Fisher Paykel Humidifier MR850 User Manual
MR850 RESPIRATORY  
HUMIDIFIER  
Technical Manual  
REVISION J  
Copyright ©2005 Fisher & Paykel Healthcare Ltd.  
Auckland, New Zealand  
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TABLE OF CONTENTS  
1
INTRODUCTION .................................................................................................................................7  
1.1 ABOUT THIS MANUAL..............................................................................................................................7  
1.2 GLOSSARY ............................................................................................................................................7  
1.3 DEFINITIONS ..........................................................................................................................................8  
1.4 PRODUCT APPLICATION..........................................................................................................................8  
2
3
HUMIDIFIER SYMBOLS.....................................................................................................................9  
SPECIFICATIONS.............................................................................................................................10  
3.1 MECHANICAL .......................................................................................................................................10  
3.2 ELECTRICAL.........................................................................................................................................10  
3.3 TEMPERATURE RANGE.........................................................................................................................10  
3.3.1 Heater Wire Mode..................................................................................................................10  
3.3.2 Non Heater Wire Mode..........................................................................................................10  
3.3.3 Alarm Parameters..................................................................................................................10  
3.4 PERFORMANCE....................................................................................................................................11  
3.5 TRANSPORT AND STORAGE ENVIRONMENTAL CONDITIONS ....................................................................11  
3.6 STANDARDS AND APPROVALS...............................................................................................................11  
4
OPERATING MODES AND CONTROLS.........................................................................................12  
4.1 HUMIDIFIER OPERATION .......................................................................................................................12  
4.1.1 Heater wire operation ............................................................................................................12  
4.1.2 Non-Heater Wire Operation...................................................................................................13  
4.1.3 Stand-by Operation................................................................................................................13  
4.1.4 Power Up Sequence..............................................................................................................14  
4.1.5 Humidity Compensation (HC) mode......................................................................................14  
4.1.6 Breathing Circuit Recognition................................................................................................15  
4.2 HUMIDIFIER CONTROLS ........................................................................................................................16  
4.2.1 Power Button .........................................................................................................................16  
4.2.2 Mode Button ..........................................................................................................................16  
4.2.3 Mute Button ...........................................................................................................................17  
4.3 TEMPERATURE DISPLAY.......................................................................................................................17  
4.3.1 Showing Chamber and Airway Temperature ........................................................................17  
4.4 SETUP INDICATORS..............................................................................................................................17  
4.4.1 Heater wire connector ...........................................................................................................17  
4.4.2 Temperature / Flow Probe Connector ...................................................................................18  
4.4.3 Chamber Probe & Airway Probe ...........................................................................................18  
4.4.4 Chamber or Airway Probe Alarm with Probe connector alarm..............................................18  
4.4.5 Water Out Indicator................................................................................................................19  
4.5 OPERATIONAL ALARMS.........................................................................................................................19  
4.5.1 Temperature Indicator ...........................................................................................................19  
4.5.2 Non-Heater Wire Operation...................................................................................................20  
4.5.3 See Manual Indicator.............................................................................................................20  
5
MAINTENANCE PROCEDURES......................................................................................................21  
5.1 MAINTENANCE SCHEDULE ....................................................................................................................21  
5.1.1 MR850 Humidifier..................................................................................................................21  
5.1.2 MR850 Temperature Probe...................................................................................................21  
5.2 SAFETY CHECK....................................................................................................................................22  
5.3 CLEANING INSTRUCTIONS.....................................................................................................................23  
5.3.1 MR850 Humidifiers ................................................................................................................23  
5.3.2 Temperature Flow Probe.......................................................................................................23  
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6
TROUBLESHOOTING ..................................................................................................................... 24  
6.1 OPERATIONAL PROBLEMS.................................................................................................................... 24  
6.2 TECHNICAL PROBLEMS ........................................................................................................................ 26  
6.3 “SEE MANUAL” ERROR CODES............................................................................................................. 27  
6.4 DIAGNOSTIC MENU.............................................................................................................................. 29  
6.4.1 Diagnostic Menu for Software Versions 5.45, 5.70............................................................... 29  
6.4.2 Diagnostic Menu for Software Version 6.00 ......................................................................... 30  
6.4.3 Diagnostic Menu for Software Version 7.00 & 7.21.............................................................. 31  
6.4.4 Diagnostic Menu for Software Version 7.14 & 7.22.............................................................. 32  
6.4.5 Diagnostic Menu for Software Version 7.23 ......................................................................... 34  
7
SERVICING PROCEDURES............................................................................................................ 35  
7.1 GENERAL CONSIDERATIONS ................................................................................................................ 35  
7.2 DISASSEMBLY ..................................................................................................................................... 35  
7.2.1 Opening the case.................................................................................................................. 35  
7.2.2 Replacing Fuses ................................................................................................................... 36  
7.2.3 Replacement of Printed Circuit Boards (PCBs).................................................................... 37  
7.2.4 Replacement of Transformer ................................................................................................ 38  
7.2.5 Servicing the Heater Plate .................................................................................................... 38  
7.2.6 Installing New Software......................................................................................................... 42  
7.2.7 Replacing the Mains Cable................................................................................................... 43  
7.2.8 Closing the case.................................................................................................................... 43  
8
PERFORMANCE TESTING ............................................................................................................. 44  
8.1 HUMIDIFIER PERFORMANCE TESTING ................................................................................................... 44  
8.1.1 Entering the Service Menu.................................................................................................... 44  
8.1.2 Humidifier Calibration Check ................................................................................................ 44  
8.1.3 Humidifier Display Test......................................................................................................... 45  
8.1.4 Humidifier Voltage Calibration Check ................................................................................... 46  
8.1.5 Humidifier Warm-up and Control Check ............................................................................... 46  
8.2 PROBE ACCURACY CHECK................................................................................................................... 47  
8.2.1 Probe Temperature Accuracy Test....................................................................................... 47  
8.2.2 Probe Flow Accuracy Test.................................................................................................... 47  
9
RECOMMENDED MAINTENANCE CHECKLIST............................................................................ 49  
9.1 HUMIDIFIER CHECK (ANNUALLY) .......................................................................................................... 49  
9.2 PROBE CHECK (EVERY SIX MONTHS).................................................................................................... 49  
10  
11  
12  
SPARE PARTS................................................................................................................................. 51  
CALIBRATION PROBE ................................................................................................................... 55  
SERIAL PORT & LOGGING SOFTWARE ...................................................................................... 56  
12.1 INTRODUCTION............................................................................................................................... 56  
12.2 INSTALLATION................................................................................................................................. 56  
12.3 OPERATING INSTRUCTIONS......................................................................................................... 56  
12.3.1 Viewing Humidifier Data........................................................................................................ 56  
12.3.2 Logging Humidifier Data to File............................................................................................. 57  
13  
14  
EMC INFORMATION........................................................................................................................ 58  
PRODUCT CHANGE HISTORY....................................................................................................... 60  
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Revision  
A
Description of Technical Manual Change  
Date Issued  
First release technical manual.  
12 Jan. 1999  
Covers Revision A PCB’s ONLY.  
B
Second release technical manual.  
6 May 1999  
Covers Revision C and later PCB’s ONLY.  
C
D
Add “View850” Software Instructions  
1 Mar. 2000  
15 May 2001  
Neonatal volume ventilation capability.  
3.4 Performance  
4.1.2 Power Up sequence.  
4.1.3 Manual Temperature Compensation (TC).  
5.3 Cleaning Instructions  
Appendix E – Product Change History.  
Covers release of software version 6.00.  
E
1 November 2001  
3.4 Performance  
Recommended Operating Temperature: 15 to 26ºC  
4.1.1 Stand-by.  
Changed stand-by power limits.  
4.1.3 Humidity Compensation (HC) mode.  
Auto HC mode option.  
4.2 Humidifier Controls  
Power button must be held for 1 second to switch OFF.  
4.4 Setup Indicators  
Two LED’s now indicate heater wire connect alarm.  
4.5 Operational Alarms  
Low temperature alarm enabled during stand-by.  
6.4 Diagnostic Menu  
“OFF” Offset removed from diagnostic menu.  
F
Covers release of software version 7.00.  
3.4 Performance  
2 April 2002  
Recommended Operating Temperature: 18 to 26ºC  
4.1.3 Humidity Compensation (HC) mode  
Changed step size to 1 °C in non-invasive mode  
4.1.4 Breathing Circuit Recognition added  
6.3 See – Manual, Error Codes  
removed redundant error code “E33”  
6.4 Diagnostic Menu  
add new functions “CHP” and “Cct”  
G
Technical manual now covers software versions 5.45, 5.70, 6.00, 7.00  
and 7.14  
1 May 2003  
The following sections have been modified: 3.3, 4.1.3, 4.1.5, 4.4, 5.3,  
6.4, 7.2.3, 7.2.6, Appendix E  
H
I
Added Non-Heater Wire Mode in sections 3.0, 4.0, 6.0, and updated  
Product Change History  
1 July 2004  
8.1.2 Humidifier Calibration Check – Equipment Required  
Removed the reference to the service kit  
10 Spare Parts  
1 August 2005  
Added parts 17 to 22.  
12.1 Introduction  
Updated how to get View850 and the serial cable  
12.2 Installation  
Changed View850 installation from floppy disk to CD  
12.3.1 Viewing Humidifier Data  
Updated how to run View850 and how to change the com. Port  
Add section, 13. EMC Information  
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Revision  
J
Description of Technical Manual Change  
Date Issued  
1.4 Product Application, Add warning to connect humidifier only to a  
pure sine wave power source  
1 November 2005  
5.2 Safety Check, add CAUTION: and NOTE:  
6.3 “See manual” Error codes, Elaborate the fault description  
8.1.5 Humidifier Warm-up and Control Check, Change test flow rate  
from 20±10 SLPM to 10±5 SLPM. Reference test limits to airway and  
chamber set temperatures rather than fixed values.  
8.2.2 Probe Flow Accuracy Test, Change test flow rate from 20±2  
SLPM to 10±1 SLPM. Check flow measurement is now between 5 and  
15 LPM  
10 Spare Parts, add items 23,24,25,26  
Note:  
1. Fisher & Paykel Healthcare have a policy of continued product improvement and reserve the right to change  
specifications without notice.  
2. This Technical Manual covers software version 5.45, 5.70, 6.00, 7.00, 7.14, 7.21, 7.22, 7.23 and PCB Revision  
C, D and E. Refer to previous revisions of the Technical Manual for earlier software and PCB versions.  
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Introduction  
1.1  
About this Manual  
This manual is intended for qualified service personnel who will perform maintenance and  
servicing on the Fisher & Paykel Healthcare MR850 Respiratory Humidifier. This manual  
covers the product specifications, includes a maintenance schedule, and provides the  
necessary information required for servicing.  
NOTE: Some software may not be available in your country. Refer to your local Fisher &  
Paykel Healthcare representative for the appropriate software version. Maintenance  
procedures should be carried out at regular intervals (as recommended in the maintenance  
schedule), to ensure that the humidifier and its accessories are working correctly.  
If a fault should occur with the humidifier, follow the troubleshooting guide (section 6) in order to  
find the most likely cause. If the unit requires servicing, make sure the servicing procedures are  
followed in order to prevent damage to the humidifier. After service, or as part of the  
maintenance schedule, a humidifier performance check should be completed.  
Due to the nature of the electronics contained within this humidifier, it is not recommended that  
the printed circuit boards be serviced at component level. Instead, if the PCBs are found to be  
malfunctioning, they should be replaced.  
1.2  
Glossary  
Chamber  
Device that allows gas to be to be heated and humidified by passing it  
over heated water.  
Temperature / Flow  
Probe  
Sensor assembly for measuring temperature and flow of respiratory  
gases traveling through the breathing circuit. Consists of a chamber  
and airway probe.  
Airway Probe  
Sensor assembly for measuring gas temperature at the end of the  
inspiratory limb.  
Chamber Probe  
Thermistor  
Sensor assembly for measuring gas flow and temperature at the  
outlet of the humidification chamber.  
A temperature sensitive resistor placed inside the chamber and  
airway probes.  
Chamber Set Point  
Airway Set Point  
The temperature that the humidifier attempts to maintain at the  
chamber probe port.  
The temperature that the humidifier attempts to maintain at the airway  
probe port.  
Heater Wire Adaptor  
Breathing Circuit  
Electrical connector between the breathing circuit and the humidifier.  
Tubing that carries respiratory gases to and from the patient.  
Dual Heated Breathing A breathing circuit that is heated by means of heater wires, in both the  
Circuit  
expiratory and inspiratory limbs.  
Single Heated  
Breathing Circuit  
A breathing circuit that is heated by means of a heater wire, in only  
the inspiratory limb.  
PCB  
Printed Circuit Board.  
Heater Wire  
Inspiratory Limb  
Wire inside the breathing circuit which heats the respiratory gases.  
The section of the breathing circuit that takes the inspired gases to  
the patient.  
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Expiratory Limb  
The section of the breathing circuit that takes the expired gases from  
the patient.  
1.3  
Definitions  
NOTE: A NOTE provides important information or explanation of procedures or conditions which  
may otherwise be misinterpreted or overlooked.  
CAUTION: A CAUTION statement designates the possibility of damage to this or other  
equipment if a procedure is not followed exactly.  
WARNING:  
A WARNING statement refers to conditions with a possibility of personal injury if a  
procedure is not followed exactly.  
1.4  
Product Application  
The MR850 is a respiratory humidifier designed for use in hospital intensive care units. It is  
used to provide optimum humidity to respiratory gases delivered to patients via endotracheal  
tubes or face masks.  
Refer to the Respiratory Humidification Product Catalogue or your local Fisher & Paykel  
Healthcare representative for a list of approved accessories.  
WARNING:  
•
The use of breathing circuits, chambers or other accessories which are not approved  
by Fisher & Paykel Healthcare may impair performance or compromise safety.  
•
•
Ensure that Invasive mode is set for patients that have bypassed airways.  
Ensure maintenance of grounding integrity by connection to a "hospital grade"  
receptacle.  
•
•
Always disconnect supply before servicing.  
When mounting a humidifier adjacent to a patient ensure that the humidifier is always  
securely mounted and positioned lower than the patient.  
•
•
•
The operation of high frequency surgical apparatus, shortwave or microwave  
equipment in the vicinity of the humidifier may adversely affect its function. If this  
occurs, the humidifier should be removed from the vicinity of such devices.  
Ensure that both temperature probe sensors are correctly and securely fitted. Failure  
to do so may result in gas temperatures in excess of 41 °C being delivered to the  
patient.  
Do not touch the glass tip of the chamber temperature probe during use. Keep black  
connectors dry at all times.  
•
•
Visually inspect accessories for damage before use.  
Normal operation can not be guaranteed if powered from a source other than a pure  
sine wave, such as a square wave inverter.  
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2
Humidifier Symbols  
Caution: Hot surfaces may  
exceed 85 °C  
Power On/Off (stand by)  
Invasive Mode  
Type BF  
Attention – consult  
accompanying documents  
Non-invasive mode  
Temperature Alarm  
Alternating Current  
Drip proof protection to IPX1  
Date of manufacture  
Serial Port  
Protective Earth  
Year-month  
C-tick for EMC  
Caution: Electrostatic  
Sensitive Device  
Do not discard  
WEEE collection (EU only)  
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3
Specifications  
3.1  
Mechanical  
Dimensions:  
Weight:  
140 mm x 173 x 135 (without chamber fitted)  
2.8 kg (without chamber fitted)  
Approx. 3.1 kg (with chamber fitted, and filled with water)  
3.2  
Electrical  
MR850 Model Number  
MR850Axx  
Supply Voltage  
230 V~  
Supply Current  
1.0 A Max  
MR850Pxx  
127 V~  
1.8 A Max  
MR850Jxx  
115 V~  
2.0 A Max  
MR850Gxx  
100 V~  
2.4 A Max  
Supply Frequency:  
50 or 60 Hz, Sine Wave  
Heater Plate Capacity  
HP Thermal Cutout:  
Heater Wire Supply:  
Maximum Heater Wire Load:  
150 W at nominal mains voltage  
118 ± 6 °C  
22 ± 5 V~, 2.73 A Max, 50 or 60 Hz  
8.0 Ω.  
3.3  
Temperature Range  
3.3.1  
Heater Wire Mode  
Invasive Mode:  
Chamber Set Point: 35.5 to 37 °C  
Chamber Set Point: 35.5 to 40 °C (versions 5.33, 5.34, 5.45, 5.70,  
6.00, 7.00, 7.21).  
Chamber Set Point: 35.5 to 42 °C (versions 7.14, 7.17 & 7.22).  
Airway Set Point: 35 to 40 °C  
Non-Invasive Mode:  
Chamber Set Point: 31 °C  
Chamber Set Point: 31 to 34 °C (versions 5.33, 5.34, 5.45, 5.70,  
6.00).  
Chamber Set Point: 31 to 36 °C (versions 7.00, 7.14, 7.17, 7.21,  
7.22).  
Airway Set Point: 28 to 34 °C  
3.3.2  
Non Heater Wire Mode  
Invasive Mode:  
Non-invasive Mode:  
Display:  
Airway Set point: 37 °C (chamber temperature limited to 66 °C)  
Airway Set point: 31 °C (chamber temperature limited to 66 °C)  
Three digit, 14 mm, 7 segment LED  
Range: 10 to 70 °C  
Accuracy:  
± 0.3 °C (in 25 to 45 °C temperature range)  
3.3.3  
Alarm Parameters  
High Temperature Alarm:  
Causes an immediate, audible and visible alarm at a displayed  
temperature of 41 °C or if the airway temperature exceeds 43 °C  
(see section 4.3)  
Temperature Alarm:  
Invasive Mode:  
After 10 minutes @ 29.5 °C causes an audible and visible alarm.  
After 60 minutes @ 34.5 °C causes an audible and visible alarm  
(see section 4.5)  
NOTE: The temperature indicator lights if the displayed  
temperature drops below 35.4 °C, initially providing a temperature  
warning.  
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Non-heater wire operation:  
Invasive Mode: Airway temperature < 29.5 °C causes an audible  
and visible alarm.  
Non-invasive Mode: Airway temperature < 26.0 °C causes an  
audible and visible alarm.  
Sound Pressure Level:  
Alarms exceed 50 dBA @ 1 m.  
3.4  
Performance  
Invasive Mode:  
Flow up to 60 LPM, humidity output >33 mg/L  
Non-Invasive Mode:  
Flow up to 120 LPM, humidity output >10 mg/L  
NOTE: Performance results with RT100 breathing circuit  
20 kPa, gas leakage at max. pressure <100 mL/minute.  
Maximum System  
Operating Pressure:  
Warm-up time:  
Less than 30 minutes.  
18 to 26 °C  
Recommended ambient  
temperature range:  
CAUTION: If operating outside the recommended ambient temperature range, consult your  
local Fisher & Paykel Healthcare representative or refer section 4.1.5.  
3.5  
Transport and Storage Environmental Conditions  
Transport Conditions:  
Storage Conditions:  
-10 to +50 °C  
-10 to +50 °C  
3.6  
Standards and Approvals  
AS/NZS 3200.1.0, CAN/CSA 22.2 No.601.1, UL 60601-1, IEC 60601-1, EN 60601-1  
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4
Operating Modes and Controls  
4.1  
Humidifier Operation  
The MR850 humidifier is designed to add heat and moisture to respiratory gases. The gas is  
passed through a humidification chamber where it is warmed and humidified.  
The MR850 has two heating systems. The first is a heater plate, which heats the water  
contained in the humidification chamber, humidifying the air passing through it. The humidifier  
monitors the temperature of the gas at the chamber outlet with the chamber probe, and controls  
the amount of power delivered to the heater plate, in order to maintain the chamber set point.  
Under normal conditions the gas is heated to 37 °C in the invasive mode, 31 °C for the non-  
invasive mode.  
4.1.1  
Heater wire operation  
Ventilator/Gas Supply  
RT100 Breathing Circuit  
Temperature Probe  
Chamber Probe  
Airway Probe  
MR290 Chamber  
Heater Wire Adapter  
MR850 Humidifier  
Figure 4.1 Typical Heater Wire Humidifier Setup  
Humidified gas from the chamber travels through the inspiratory limb, where its temperature  
must be maintained in order to prevent the generated humidity from condensing. This is  
achieved with a heater wire encapsulated within the inspiratory limb. The humidifier maintains  
the temperature along the inspiratory limb by monitoring the temperature at the airway probe  
and controlling the power delivered to the heater wire. Under normal conditions the gas is  
heated to 40 °C in the invasive mode, 34 °C for the non-invasive mode.  
An optional, second heater wire, located in the expiratory limb, minimises condensate in this  
limb.  
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4.1.2  
Non-Heater Wire Operation (Software version 7.23 only)  
Ventilator/Gas Supply  
RT134 Breathing Circuit  
Temperature Probe  
Chamber  
Probe  
Airway Probe  
MR290  
Chamber  
Water trap  
MR850 Humidifier  
Figure 4.2 Typical Non-Heater Wire Humidifier Setup  
In this application the MR850 maintains the airway temperature at the desired set point  
(invasive 37 °C or non-invasive 31 °C) by heating the chamber of water through the heater  
plate. As the gas cools considerably down the unheated circuit, a water trap circuit must be  
used to collect the resulting condensate.  
Activating Non-Heater Wire Operation  
Refer also to the diagnostic menu in section 6.4.  
1
2
Turn on the humidifier with NO heated circuit connected, and mute the heater wire alarm.  
Access the diagnostic menu by pressing the mute and mode buttons together for 1 second,  
the display should show two rows of dashes ‘= = =’. Releasing both buttons will allow the  
diagnostic menu to cycle automatically.  
3
4
Allow the menu to cycle through to “cct” – the circuit identification. Press mute to access  
this function.  
To enable non-heated operation, press both mute and mode buttons simultaneously for 1  
second, the humidifier will beep twice and the temperature display will show “nhh”.  
Release both buttons. The humidifier is now configured for non-heated circuits. This  
setting will be remembered each time the humidifier is turned on.  
Deactivating Non-Heater Wire Operation  
The simplest way to de-activate non heater wire operation is to connect a heated breathing  
circuit. Alternatively it can be de-activated the same way that non-heated circuit operation was  
activated (see above).  
4.1.3  
Stand-by Operation  
If the humidifier detects a problem with its setup or operation it will alarm. Depending on the  
severity of the alarm condition, the humidifier will either remove all power from the heating  
systems, or enter stand-by. The humidifier will also enter stand-by if the gas flow through the  
breathing circuit has stopped.  
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Stand-by (Software versions: 5.45 & 5.70)  
•
•
•
•
Heater wire power is set at 30 %.  
Control of chamber temperature is attempted, within the following limits:  
Heater plate temperature is limited to 60 °C.  
Heater plate power is limited to 20 %.  
Stand-by (Software version: 6.00 onward)  
•
•
•
•
Heater wire power is set at 15 %.  
Control of chamber temperature is attempted, within the following limits:  
Heater plate temperature is limited to 50 °C.  
Heater plate power is limited to 20 %.  
NOTE: The temperature alarm algorithm continues to function in stand-by.  
4.1.4 Power Up Sequence  
The purpose of the power up sequence is to perform internal checks on various parts of the  
humidifier and provide the user with a visual and audible check.  
Internal self test sequence:  
1. Test presence of heater wire.  
2. Test correct operation of heater wire triac.  
3. Test correct operation of protection relays.  
4. Test integrity of temperature/flow probe.  
Visual/Audio test sequence:  
1. The temperature display and indicator LEDs turn on.  
2. The temperature display is blanked and indicators set to their default.  
3. Display shows humidifier model number i.e. 850.  
4. Display is blanked.  
5. Display shows software version number.  
6. Display is blanked and an audio tone of 2100 Hz sounds.  
7. Normal display.  
4.1.5  
Humidity Compensation (HC) mode (Software version 6.00 onward, except 7.23)  
Normal ambient environments between 18 °C and 26 °C do not affect humidity output of  
temperature controlled heated humidifiers. However once the ambient temperature increases  
above 26 °C, and/or the temperature of the incoming gas becomes greater than 32 °C, e.g. due  
to ventilator heating, then the humidity output maybe reduced.  
This can be identified by the lack of beading condensate on the inner walls of the humidification  
chamber and rectified by modifying the breathing circuit or humidifier settings. Increasing the  
length of breathing circuit between the ventilator and the humidification chamber will assist in  
cooling the gas before it enters the chamber and improve humidity output.  
If beading condensate does not form, humidity output can be further improved by increasing the  
humidifier’s chamber set point. This can be achieved by accessing the HC mode (or Tc) in the  
Diagnostic Menu (see section 6.4) and either manually selecting a level of chamber temperature  
compensation or letting the automatic mode do it for you.  
Automatic Humidity Compensation  
When automatic HC mode is selected the humidifier calculates the power required to  
adequately humidify the gas flow through the chamber. If the minimum power level is not met  
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then the chamber set point will automatically be increased in 0.5 °C steps (1 °C steps for non-  
invasive mode) until the minimum power is achieved. The maximum amount of compensation  
applied is either 3 or 5 °C depending on the mode and software version (section 6.4 Diagnostic  
Menu details how compensation is applied for each software version).  
If conditions improve and too much power is being applied, then the MR850 will automatically  
reduce the chamber set temperature.  
NOTE: Excessive condensate may form in the breathing circuit if the auto HC function is used  
with turbine driven ventilators (i.e. ventilators that use room air). It is recommended to switch off  
the auto HC function in these situations if the condensate becomes excessive.  
NOTE: Auto HC function is factory set to enabled on all MR850 models.  
Manual Humidity Compensation  
For manual HC the level of compensation should be increased until beading condensate is  
observed on the inner walls of the humidification chamber. It should be noted that if  
environmental conditions change then it might be necessary to re-adjust this setting. For  
example, a fall in room temperature could produce a build up of unwanted condensate in the  
delivery circuit. A reduction in this setting may stop further build up.  
NOTE: The previous manual HC setting is restored when power is applied to the humidifier  
Refer to section 6.4 Diagnostic Menu for further information regarding this feature.  
Activating/Deactivating Humidity Compensation  
Refer also to the diagnostic menu in section 6.4  
1. Access the diagnostic menu by pressing the mute and mode buttons together for 1  
second, the diagnostic menu is entered, indicated by the display of two rows of dashes  
‘= = =’. Releasing both buttons will allow the diagnostic menu to cycle automatically  
through the menu.  
2. The first item is “HC” this is the humidity compensation item, press and hold mute to  
access this function.  
3. The setting may show either ‘0’ or ‘-A-‘ to change the setting press both mute and mode  
buttons simultaneously for 1 second, the humidifier will beep twice and the setting will  
increase. Release both buttons.  
4. To increase again repeat step 3. To decrease the setting press the mute and power  
buttons for 1 second.  
5. To exit the menu, release all buttons, the menu will continue to cycle until ‘end’ is  
displayed, the menu will automatically exit.  
Temperature Display  
To alert users during normal operation that either manual or automatic HC mode has been  
enabled, the decimal point on the temperature display will flash. Each of the two modes can be  
further identified by the flash rate, where auto HC mode has a slower flash rate than manual HC  
mode.  
Note: The displayed temperature may also be higher than normal indicating (up to 39°C) the  
amount of compensation present.  
4.1.6  
Breathing Circuit Recognition (Software version 7.00 onward)  
Fisher & Paykel Healthcare has developed a range of breathing circuits that offer optimum  
performance for the type of treatment selected while working within recommended operating  
conditions. Some of these breathing circuits require a slightly modified controller to optimize  
performance. To do this the MR850 must first recognize what type of delivery circuit has been  
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connected. Breathing circuit recognition is performed via three electrical connections on the  
heater wire adaptor. Re-configuring the electrical connection pins on a heated circuit and the  
way it connects to this adaptor identifies the type of heated circuit. In this way three separate  
heater wire circuits can be identified by the MR850.  
4.2  
Humidifier Controls  
4.2.1  
Power Button  
The humidifier will power on if this button is held down briefly, but must be held  
for one second to turn the humidifier off.  
Note: For software version 5.45, 5.70 the power button need only be pressed  
briefly to turn off the MR850.  
CAUTION: Although the display is not illuminated, the unit may still be  
energized. Be sure to disconnect power from the MR850 before servicing.  
After power-on the humidifier starts an internal diagnostic routine which checks  
for possible problems in the humidifier setup. If everything is working correctly,  
normal control is initiated.  
4.2.2  
Mode Button  
When held down for one second, the mode button toggles the humidifier  
between Non-Invasive and Invasive mode. The Mode indicator LED shows the  
user which mode is selected.  
Invasive mode is for use with patients whose upper airways have been  
bypassed by either a tracheostomy or endotracheal tube. In this mode of  
operation the humidifier attempts to deliver optimal humidity to the patient (37  
°C, 100 % RH). This mode is the default mode on power up of the humidifier.  
The humidifier normally controls the chamber outlet temperature to 37 °C, and  
the airway temperature to 40 °C, maintaining a +3 °C temperature gradient  
along the inspiratory limb1.  
If however this temperature gradient is not maintained, the chamber set point is  
reduced in 0.5 °C steps (minimum setting of 35.5 °C), in order to reduce  
condensate buildup in the breathing circuit2. If the chamber set point is less  
than 37 °C and sufficient temperature gradient has been maintained along the  
inspiratory limb, then the chamber set point is increased back up to 37 °C in 0.5  
°C steps.  
Non-Invasive mode is suitable only for patients whose natural humidification  
system (i.e. upper airways) has not been bypassed, but are receiving gas via a  
facemask or similar.  
The humidifier normally controls the chamber outlet temperature to 31 °C, and  
the airway temperature to 34 °C, maintaining a +3 °C temperature gradient  
along the inspiratory limb1.  
1 If automatic or manual humidity compensation has been activated then the displayed temperature may be higher  
than 37 °C (Invasive mode) or 31 °C (Non-Invasive mode).  
2 The humidity compensation algorithm takes precedence over the condensation control algorithm.  
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4.2.3  
Mute Button  
The mute button silences the humidifier's audible alarm. The muted time  
depends on the alarm condition. In general, alarms will be muted for 2 minutes.  
A chamber or airway probe alarm is muted for a longer time, until the humidifier  
determines whether the probe is in or out. The temperature alarm is treated  
differently - see section 4.5.  
4.3  
Temperature Display  
The front panel shows the lower of the chamber or airway temperatures. This temperature  
gives an indication of the dew point (in °C) of the gas that is being supplied to the patient. The  
dew point of a gas is the best indication of both its humidity and energy content. Under normal  
operation, the displayed temperature will be the chamber temperature, as its control set point is  
lower. If the temperature is above 70 °C, "Hi" will be displayed. If the temperature is below 10  
°C, "Lo" will be displayed. If HC mode has been enabled the decimal point on the temperature  
display will flash.  
4.3.1  
Showing Chamber and Airway Temperature  
Both the chamber and airway temperature can be displayed by pushing and holding the mute  
button for 1 second. The temperatures are displayed in the following sequence:  
1
Chamber temperature is displayed until two seconds after the mute button is released. The  
chamber probe indicator (see section 4.4) will also light to show which temperature is being  
displayed.  
2
The display will blank, and then the airway temperature will be displayed until two seconds  
after the mute button is released. The airway probe indicator will also light (see section 4.4)  
to show which temperature is being displayed.  
3
The temperature display will blank again, and revert to normal operation.  
4.4  
Setup Indicators  
The MR850 setup indicators, placed on the lower left of the front panel, are intended to aid the  
user in identifying problems with the incorrect setup of the device and its accessories.  
4.4.1  
Heater wire connector  
These indicators light if the heater wire in the breathing circuit has not been  
connected correctly, or if the heater wire or heater wire adaptor is faulty. An  
intermittent connection, or excessive current (total current in all limbs > 3.5 A) in  
the heater wires will also produce this alarm. The humidifier will remove power  
from the heating systems if this alarm is active.  
NOTE: Software versions 5.45 and 5.70 do not light the upper indicator located  
on the breathing circuit.  
NOTE: Software versions 7.22 and 7.23 in non heater wire operation and  
without a heater wire connected no audible or visual heater wire alarm will be  
given. Connecting a heated wire circuit will automatically cause the MR850 to  
default to heater wire operation.  
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4.4.2  
Temperature / Flow Probe Connector  
This indicator will light if the temperature probe is not correctly plugged in, or the  
probe used is faulty. The humidifier tests for the following probe fault conditions:  
• Temperature probe disconnected  
• Chamber thermistor open or short circuit  
• Airway thermistor open or short circuit  
• Flow thermistor open or short circuit (shorted probe test)  
• One thermistor shorted to another (shorted probe test)  
• Flow calibration resistor open or short circuit (shorted probe test)  
An alarm will be generated if any of the above faults are found, and the  
humidifier will remove power from all heating systems.  
NOTE: the shorted probe tests and flow thermistor tests are only performed on  
start-up, or when temperature probe or heater wire alarms are cancelled.  
4.4.3  
Chamber Probe & Airway Probe  
These indicators are used to show that either the chamber probe or airway  
probe is not inserted into the breathing circuit correctly. On start-up, and during  
rapid changes in temperature, the humidifier tests to see if a probe is in place by  
cooling and then heating the probe. If the humidifier finds that either probe is  
not inserted into the breathing circuit, an alarm will be generated and the  
humidifier will enter stand-by. During this alarm the humidifier will initiate a  
probe out test periodically, or a test will be initiated immediately after mute has  
been pressed.  
During periods of low or zero gas flow, the airway probe out alarm is disabled.  
As soon as flow is detected however, an airway probe test is initiated.  
NOTE: For software versions 7.22 and 7.23 in non-heater wire operation, the  
airway probe out alarm does not function, instead the low temperature of the  
disconnected probe will activate the temperature alarm (refer section 4.5).  
4.4.4  
Chamber or Airway Probe Alarm with Probe connector alarm  
The humidifier checks to see if the temperature probe is faulty by testing for the  
following conditions:  
• Chamber temperature has been greater than 50 °C for 20 minutes  
• Chamber temperature is greater than 80 °C  
• Airway temperature has been greater than 50 °C for 5 minutes  
• Airway temperature is greater than 80 °C  
If an apparent fault is found, the humidifier will give a temperature / flow probe  
connector alarm, and also indicate either the chamber or airway probe. The  
humidifier will stay in stand-by until the chamber or airway temperature drops  
below 50 °C. Once this occurs, a probe test will also be initiated.  
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4.4.5  
Water Out Indicator  
This indicates that there is insufficient water in the humidification chamber.  
The humidifier measures the amount of power used to obtain the chamber  
temperature. If a lower than expected amount of power is used, a 'water out'  
alarm is generated. It may take 15 minutes or longer to generate an alarm  
especially if there is a disturbance (change in flow).  
This alarm can be cancelled by pressing the mute button. If however the water  
out condition remains, the humidifier will alarm again.  
4.5  
Operational Alarms  
These alarms are generated if problems occur with the operation of the humidifier.  
4.5.1  
Temperature Indicator  
This alarm will occur if the displayed temperature is too high, or if the delivered  
temperature (Invasive mode only) has been low for a period of time.  
High temperature:  
The humidifier will immediately alarm if at any time the displayed temperature  
exceeds 41 °C, or if the airway temperature exceeds 43 °C. If either of these  
high temperature alarms occur, the humidifier will immediately shut down the  
heater wire and heater plate.  
Low Temperature:  
The low temperature warning (visual only) and alarm (visual and audible) are  
active only when the humidifier is in Invasive mode. Both are disabled during  
warm-up conditions. The warning alerts the user that low temperature is being  
delivered to the patient. The alarm alerts the user that a low level has been  
delivered to an Invasive patient for too long.  
The low temperature warning and alarm operate by monitoring the displayed  
temperature. If the displayed temperature is below 35.5 °C for 25 seconds, the  
temperature indicator will light, and act as a warning to the user. If the  
temperature remains below this level for too long, then a Temperature Alarm is  
activated. The time taken for the humidifier to alarm is dependent on how far  
below the 35.5 °C threshold the displayed temperature is. Figure 4.3 shows the  
relationship between temperature, a temperature warning and the time before a  
temperature alarm:  
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Figure 4.3 Temperature vs Time to Alarm  
Pressing mute during a temperature alarm silences the alarm for half the normal  
time period, if the same temperature is maintained.  
The low temperature warning and alarm can be caused by cold or drafty  
ambient conditions, or can result from using gas flow rates outside the  
specification of the breathing circuit, chamber or humidifier.  
NOTE: The low temperature alarm is disabled in stand-by on software version  
5.45 and 5.70.  
4.5.2  
Non-Heater Wire Operation (Software versions 7.22 & 7.23)  
When the airway temperature exceeds 41 °C, the heater plate is shut off, and  
an immediate visible and audible high temperature alarm is activated.  
In invasive mode, the low temperature warning and alarm is identical for the  
heater wire mode (see above) after warm-up.  
In addition the airway temperature must reach 29.5 °C in invasive mode (or 26  
°C for non-invasive mode) within 15 minutes, otherwise a visible and audible low  
temperature alarm will be given, and the heater plate will be switched off. This  
will occur if the airway probe has not been inserted into the breathing circuit.  
After warm-up, if the airway temperature drops below 29.5 °C (or 26 °C non-  
invasive mode), a visible and audible low temperature alarm will be given, and  
the heater plate will be switched off.  
NOTE: The low temperature alarm will be inactive in stand-by.  
4.5.3  
See Manual Indicator  
This indicates a serious hardware fault. Please refer to section 6,  
"Troubleshooting".  
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5
Maintenance Procedures  
In order to keep your humidifier in good working order, it is necessary to perform maintenance  
at regular intervals.  
5.1  
Maintenance Schedule  
5.1.1  
MR850 Humidifier  
Annually  
a. Check MR850 for physical damage:  
•
•
•
Check the mains cable for damage, replace if necessary.  
Check the heater plate for deep scratching etc., replace if necessary.  
Check the heater wire adaptor for kinks, abrasions and damaged connectors. Check  
that the plugs couple with the sockets on the humidifier.  
b. Carry out a full performance test. This procedure is detailed in section 8.  
NOTE: A maintenance check sheet is given in Section 9.  
5.1.2  
MR850 Temperature Probe  
Every Six months  
a. Visually check the humidifier probes for physical damage:  
•
Check that the chamber probe's glass thermistor has not been damaged. Replace  
probe if required.  
•
Inspect the chamber probe's glass thermistor for deposits or foreign material. Clean  
probe as required.  
•
•
Check the probe cable for kinks and abrasions etc.  
Check that the probe connectors couple with the humidifier sockets.  
b. A temperature accuracy check and flow accuracy check should be performed on the MR850  
temperature probe as outlined in section 8.2.  
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5.2  
Safety Check  
The unit should be tested to the current medical electrical standards for in-house testing for  
each specific country (example, refer to AS/NZS 3551 for Australia and New Zealand).  
CAUTION: Permanent damage to this humidifier will result if the serial port is used as a  
ground point during electrical safety testing.  
NOTE: The correct ground test point location is on the heater plate front underside edge, as  
shown in Figure 5.1., where the insulating anodizing layer has been removed.  
Figure 5.1 Showing the correct location of ground test point on the heater plate  
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5.3  
Cleaning Instructions  
5.3.1  
MR850 Humidifiers  
It is recommended that only the following cleaners be used on the MR850 as at the time of  
revision of this technical manual. The disinfectants in the list below have been tested to ensure  
that no damage will result to the outer plastic or metal components of the humidifier.  
1. Disconnect the humidifier from any electrical outlet.  
2. Clean the humidifier with one of the following recommended disinfectants using a damp  
cloth:  
Isopropyl Alcohol  
Normal dishwashing detergent  
NOTE:  
Follow the manufacturer’s instructions carefully.  
Use the correct dilution of the disinfectant.  
DO NOT immerse the humidifier in any liquid.  
3. Wipe the humidifier clear of any cleaning residues before use.  
5.3.2 Temperature Flow Probe  
The cleaning methods listed below meet the FDA regulations for these types of devices, and do  
not affect the integrity or performance of the probe. It is the user’s responsibility to qualify any  
deviations from these procedures, both for disinfecting efficacy and physical effect on the probe.  
For advice on other cleaning methods not mentioned here, contact your local Fisher and Paykel  
Healthcare distributor.  
NOTE: Refer also to the disinfection instructions on the instruction sheet for the airway  
temperature probe, Ref 185042434.  
1. Physically clean the probes, removing all visible contaminants.  
2. Disinfect the probes with one of the following solutions:  
Sporicidin; Sporox; Cidex; Cidex OPA  
OR Sterilise the probe using Ethylene Oxide sterilisation at 55 °C (131 °F), 80 kPa,  
allow at least 15 hours for residual ETO to disperse before use.  
NOTE: Follow the manufacturer’s instructions carefully. Use the correct dilution of the  
disinfectant.  
CAUTION: DO NOT immerse the black electrical connector plug in disinfectant.  
DO NOT autoclave probes.  
DO NOT use dishwater detergents or solvents.  
3. Wipe the airway temperature probes clear of any cleaning residues before use.  
4. Store in clean conditions.  
Cidexis a registered trademark of Johnson & Johnson Medical Pty. Ltd. North Ryde, NSW, Australia.  
Sporicidinis a registered trademark of Sporicidin International Ltd, Rockville, MD 20852, USA.  
Sporoxis a registered trademark of Reckitt & Colman Inc. 1655 Valley Rd. Wayne NJ USA  
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6
Troubleshooting  
6.1  
Operational Problems  
This section deals with faults that cause the humidifier to alarm. This may be caused by  
incorrect setup, faulty accessories, or a faulty humidifier. Refer below for troubleshooting.  
Symptom  
Corrective Action  
Reference  
See manual  
Record the displayed error code.  
Section 6.3  
indicator flashing  
with audible alarm  
See manual  
indicator light  
permanently on,  
without an audible  
alarm  
1. If “PtS” is displayed on the front panel, then the production Section 7.2.6  
test mode has been accessed. Check the production test  
button is not depressed or mode set by serial command.  
2. Humidifier faulty. Replace PCBs.  
Section 7.2.3  
Water Out indicator 1. Check that there is sufficient water in the chamber. Refill  
flashes,  
accompanied by an  
audible alarm  
or replace chamber as necessary. Check that the water  
bag is not empty, and the delivery tube is not kinked or  
occluded.  
2. Check that the water level in the MR290 chamber is not  
above the marked line. Replace chamber if the water is  
above this line.  
3. Check that the gas flow rate is within specification of the  
humidifier and accessories being used. Adjust as  
necessary.  
4. Has condensate formed on the chamber probe? Dry  
Probe and re-insert.  
5. Temperature probe faulty. Complete a temperature and  
flow accuracy test on the probe. Replace probe as  
required.  
Section 8.2  
Section 8  
6. Humidifier faulty. Complete a performance test. Service  
humidifier as required.  
Chamber Probe  
alarm flashes  
accompanied by an  
audible alarm  
1. Check that the chamber probe is inserted into the  
breathing circuit correctly, and that the breathing circuit is  
set up correctly.  
2. Check that there is sufficient water in the chamber. Refill  
as necessary. Check that the water bag and delivery tube  
are not kinked or occluded.  
3. Ensure correct chamber is being used (refer Operating  
Manual)  
4. Check that the gas flow rate is within specification of the  
humidifier and accessories being used. Adjust as  
necessary.  
5. Has condensate formed on the chamber probe? Dry  
probe and re-insert.  
6. Temperature probe or humidifier faulty. Complete  
performance tests. Replace probe or service humidifier as  
required.  
Section 8  
Heater wire  
connector alarm  
flashes,  
accompanied by an  
audible alarm  
1. Check that the heater wire adaptor is correctly plugged into  
the humidifier along with the breathing circuit.  
NOTE: The short lead must connect to the inspiratory limb.  
2. Replace breathing circuit, and re-rest.  
3. Replace heater wire adaptor, and check for intermittent  
connections. Re-test.  
4. Humidifier faulty. Replace PCBs.  
Section 7.2.3  
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Symptom  
Corrective Action  
Reference  
Heater wire alarm  
not working  
Non-heater wire mode has been activated, connect a heated  
wire circuit or disable this mode via the diagnostic menu.  
Section 4.1.2  
Airway Probe  
alarm flashes along  
with an audible  
alarm  
1. Check that the airway probe is inserted into the breathing  
circuit correctly, the breathing circuit assembled correctly,  
and that there is water in the chamber.  
2. Check that the circuit is connected correctly to the  
ventilator – gas flow could be reversed through the  
humidifier.  
3. Check that the gas flow rate is within specification of the  
humidifier and type of accessories being used. Adjust as  
necessary.  
Section 3.4  
Section 8.2  
4. Check for excessive condensate build up. Excessively  
cold or drafty ambient conditions may cause this alarm to  
occur. Ensure there are no strong drafts around the  
breathing circuit.  
5. Complete a probe accuracy check. Replace probe as  
necessary.  
6. Humidifier faulty. Replace PCBs.  
Temperature / Flow 1. If the Temperature / Flow Probe alarm occurs with  
Section 4.4  
Section 8.2  
Probe alarm with  
airway or chamber  
indicators flashing  
chamber or airway indicators also flashing, the  
temperature probe is faulty.  
2. Complete a probe accuracy check, and replace probe if  
required.  
Temperature probe 1. Is the probe connector correctly plugged into the  
connector indicator  
flashes,  
accompanied by an  
audible alarm  
humidifier? Plug in probe as required.  
2. Check that the circuit is connected correctly to the  
ventilator – gas flow could be reversed through the  
humidifier.  
3. Perform a humidifier calibration check.  
Section 8.1.2  
Section 8.2  
4. Replace temperature probe and re-test. If the alarm  
condition disappears, the temperature probe is faulty.  
Discard faulty probe.  
5. Humidifier faulty. Replace PCBs.  
Section 7.2.3  
Temperature  
The humidifier has been unable to maintain temperature over a  
period of time.  
1. Gas flow has been disconnected from the humidifier either  
reconnect gas flow or turn the humidifier off.  
Indicator flashes,  
with audible alarm,  
coupled with a low  
temperature  
(< 35.5 °C)  
displayed  
2. Check that the gas flow rate is within specification of the  
humidifier and accessories being used.  
3. Check for drafts around the breathing circuit. This can be  
caused by fans or room air conditioning. If this is found to  
be the cause, the breathing circuit should be shielded from  
the ambient airflow.  
4. Check that the circuit is connected correctly to the  
ventilator – gas flow could be reversed through the  
humidifier.  
WARNING: Never cover the breathing circuit.  
5. Check for excessive condensate pooling in the breathing  
circuit. Drain circuit if necessary.  
6. Humidifier or probe faulty? Complete humidifier & probe  
performance test. Replace probe or service humidifier as  
required.  
Section 8  
7. Check that there is sufficient water in the chamber. Refill  
as necessary. Check that the water bag and delivery tube  
are not occluded.  
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Symptom  
Corrective Action  
Reference  
A low temperature  
is shown on the  
humidifier’s  
display, with no  
audible alarm  
1. Make sure the humidifier has had time to warm up and that  
there is sufficient gas flow through the breathing circuit.  
2. The humidifier cannot maintain temperature. If the  
temperature indicator is also on then an alarm will occur  
eventually.  
Section 4.5  
Section 8  
3. Humidifier or probe faulty. Complete humidifier and probe  
performance test. Replace probe or service humidifier as  
required.  
High displayed  
temperature, no  
temperature alarm  
1. Flow has recently been changed, allow 30 minutes for  
temperature to stabilise  
2. Manual or automatic humidity compensation is active  
Section 4.1.5  
Section 8  
Temperature  
indicator flashes,  
with audible alarm,  
and a high  
temperature is  
shown.  
The gas flow rate may have suddenly changed. Monitor  
the displayed temperature, if the temperature does not fall  
rapidly then remove humidifier from patient, and complete a  
performance test on the humidifier, and temperature / flow  
probe. Replace probe or service humidifier as required.  
6.2  
Technical Problems  
Problems that cause the humidifier to malfunction without an audible alarm are discussed in this  
section.  
Symptom  
Corrective Action  
Reference  
See manual  
indicator lit (not  
flashing)  
1. Check that the mains supply is within specification.  
Provide adequate mains supply if required.  
2. If ‘PtS’ is displayed.  
Section 6.1  
3. Replace PCBs.  
Section 7.2.3  
Humidifier will not  
turn on with on/off  
button, and no  
1. Humidifier plugged into mains supply?  
2. Check that the mains supply is within specification.  
Provide adequate mains supply if required.  
indicators are lit  
3. Remove mains power and check the fuses.  
Section 7.2.2  
Section 7.2.7  
4. Check continuity of mains power cord. Replace as  
necessary.  
5. Check the transformer windings are not open circuit.  
Primary Winding: Red wires  
Section 7.2.4  
Secondary 10v winding: White wires  
Secondary 22v winding: Yellow wires  
If any windings are open circuit, replace the transformer.  
6. Replace PCBs.  
Section 7.2.3  
Section 7.2.3  
Unit fails  
calibration check  
Send unit to a Fisher & Paykel Healthcare service  
representative for calibration, or replace PCBs.  
Probe fails Probe  
Accuracy Check  
Replace probe.  
Unit fails to reach  
temperature in  
humidifier control  
check. (Section  
8.1.4)  
1. If the chamber outlet temperature was low, the heater plate Section 7.2.5  
element should be checked. Replace element as  
necessary.  
2. If the airway temperature was low, replace breathing circuit  
and re-test.  
3. Replace PCBs.  
Section 7.2.3  
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6.3  
“See Manual” Error Codes  
The following is an explanation of the error codes that are displayed in conjunction with the See  
Manual indicator flashing. A code is not displayed if the microprocessor has stopped  
functioning (see technical problems - section 6.2).  
Error Description of Fault  
E00  
E02  
E03  
E04  
E05  
E06  
No fault  
Microprocessor stack overflow  
RAM fault  
ROM fault  
EEPROM version older than ROM version. Update EEPROM. Refer to Section 7.2.6  
EEPROM version newer than ROM version – (old software). Contact Fisher & Paykel  
Healthcare  
E07  
Model mismatch with software, contact your Fisher & Paykel Healthcare  
representative.  
NOTE: included in software version 7.14 onward, except 7.21.  
Temperature circuit calibration out of range: Range Amp 0: 25.5 °C  
Temperature circuit calibration out of range: Range Amp 0: 65.0 °C  
Temperature circuit calibration out of range: Range Amp 1: 25.5 °C  
Temperature circuit calibration out of range: Range Amp 1: 34.5 °C  
Temperature circuit calibration out of range: Range Amp 2: 34.5 °C  
Temperature circuit calibration out of range: Range Amp 2: 44.6 °C  
Temperature circuit calibration out of range: Range Amp 3: 65.0 °C  
Heater wire circuit has malfunctioned, heater can not be energized:  
E10  
E11  
E12  
E13  
E14  
E15  
E16  
E20  
-
-
-
Heater plate thermal cutout tripped (section 7.2.5)  
Heater wire fuse (F2) is open circuit (section 7.2.2)  
Heater wire triac, or heater wire relay is open circuit  
E21  
Heater wire circuit has malfunctioned, heater either can not be de-energized or  
monitoring circuit has failed :  
-
-
Heater wire triac has shorted  
Heater wire sense circuit has failed  
E23  
E25  
E26  
E27  
E28  
E29  
E2A  
E2C  
Heater wire voltage measurement circuit faulty  
Transistor Q17 is not turning on  
Transistor Q16 is not turning on  
The heater wire relay is short circuited  
Mains voltage measurement is uncalibrated (section 8.1.3)  
The heater plate thermistor is short circuited  
The heater plate thermistor is open circuit  
Heater plate element circuit has malfunctioned is not turning on:  
-
-
-
Element is open circuit  
Heater plate triac or driver faulty  
Heater plate relay is faulty  
E2D  
E30  
E31  
E32  
E40  
The heater plate element is not turning off. Heater plate triac circuit faulty.  
Power (on/off) button stuck on  
Mute button stuck on  
Mode button stuck on  
Unit not functional tested at time of manufacture  
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Error Description of Fault  
E41  
E42  
E43  
E44  
E45  
E4A  
E4B  
E4C  
E50  
E51  
Failed the functional test at time of manufacture  
Was not stress tested during manufacture  
Failed the stress test during manufacture  
Not tested on functional tester 2  
Failed production functional tester 2  
EEPROM write error occurred  
EEPROM write verify error occurred  
EEPROM read error occurred  
Flow circuitry not functioning  
Flow circuitry shorted on  
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6.4  
Diagnostic Menu  
By pressing the mute and mode buttons together for 1 second, the diagnostic menu is entered,  
indicated by the display of two rows of dashes ‘= = =’. Releasing both buttons will allow the  
diagnostic menu to cycle automatically through the menu, pausing at each function. Pressing  
the mute button at this time will display the value behind each function for as long as the mute  
button is held.  
6.4.1  
Diagnostic Menu for Software Versions 5.45 & 5.70  
Display  
Description  
TC  
Temperature Compensation (TC) algorithm  
‘---‘ = 0.0 °C of chamber compensation. ( CSP = 37.0 °C)  
‘Lo ’ = 1.5 °C of chamber compensation. ( CSP = 38.5 °C )  
‘Hi ’ = 3.0 °C of chamber compensation. ( CSP = 40.0 °C )  
To change the TC value the press the Mute and Mode buttons together for 1  
second. The humidifier will confirm the change with a double-beep.  
CSP  
Chamber set point, in 0.1 °C resolution e.g.: 37.0  
Chamber Duty Cycle (%)  
Cdc  
HP  
Flo  
Heater Plate Temperature (1 °C)  
Gas Flow Rate (0.1 LPM)  
“---“ = Unknown Flow (flow measurement not started)  
Gas Flow Rate Range:  
FLr  
“---“ = Unknown Flow (flow measurement not started)  
“no” = No flow  
“Lo” = Low flow, ( < 3 LPM )  
“In” = Intermediate flow, ( 2 to 17 LPM )  
“Hi” = High flow, ( > 14 LPM )  
“ -“ = Ventilated flow detected  
OFF  
Offset temperature difference between the chamber and airway set temperatures  
(0.1 °C)  
ASP  
Adc  
LAS  
Airway temperature set point (0.1 °C)  
Airway Duty Cycle (%)  
Last Humidifier Alarm State, the display will blank, and the humidifier’s last alarm  
will be shown on the indicators. To clear LAS, press and hold the mute and mode  
buttons for 1 second. The humidifier will beep when LAS has been cleared.  
LFS  
Last Humidifiers Fault State, refer to section 6.3. To clear LFS, press and hold the  
mute and mode buttons for 1 second. The humidifier will beep when LFS has been  
cleared.  
SoF  
End  
Software version  
Press the mute button to cycle to the start of the menu, or the diagnostic menu will  
automatically exit after 6 seconds  
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6.4.2  
Diagnostic Menu for Software Version 6.00  
Display  
Description  
HC  
Humidity Compensation (HC) algorithm  
Invasive mode, compensation range is 0.0 to 3.0 °C ( CSP = 37.0 to 40 °C )  
Non-Invasive mode, compensation range is 0.0 to 5.0 °C ( CSP = 31.0 to 36.0 °C )  
By pressing the Mute and Mode buttons together for 1 second or pressing the Mute  
and Power buttons together for 1 second the user can respectively move up or  
down through the settings listed below. The humidifier will confirm the change with  
a double-beep.  
‘5.0’ = +5.0 °C of chamber compensation (Non-Invasive mode only)  
‘4.0’ = +4.0 °C of chamber compensation (Non-Invasive mode only)  
‘3.0’ = +3.0 °C of chamber compensation  
‘2.0’ = +2.0 °C of chamber compensation  
‘1.0’ = +1.0 °C of chamber compensation  
‘0.0’ = +0.0 °C of chamber compensation (NO compensation)  
‘-A-‘ = Automatic humidity compensation mode:  
Invasive mode: 0 to 3 °C in 0.5 °C steps  
Non-invasive mode: 0 to 3 °C in 0.5 °C steps  
Chamber set point, in 0.1 °C resolution eg: 37.0  
Invasive mode range 35.5 to 40 °C.  
CSP  
Non-Invasive mode range 31.0 to 36.0 °C.  
Chamber Duty Cycle (%)  
Cdc  
HP  
Flo  
Heater Plate Temperature (1 °C)  
Gas Flow Rate (0.1 LPM)  
“---“ = Unknown Flow (flow measurement not started)  
Gas Flow Rate Range:  
FLr  
“---“ = Unknown Flow (flow measurement not started)  
“no” = No flow  
“Lo” = Low flow, ( < 3 LPM )  
“In” = Intermediate flow, ( 2 to 17 LPM )  
“Hi” = High flow, ( > 13 LPM )  
“ -“ = Ventilated flow detected  
ASP  
Adc  
LAS  
Airway temperature set point (0.1 °C)  
Airway Duty Cycle (%)  
Last Alarm State, the display will blank, and the humidifier’s last alarm will be shown  
on the indicators. To clear LAS, press and hold the mute and mode buttons for 1  
second. The humidifier will beep when LAS has been cleared.  
LFS  
Last Fault State, refer to section 6.3. To clear LFS, press and hold the mute and  
mode buttons for 1 second. The humidifier will beep when LFS has been cleared.  
SoF  
End  
Software version  
Press the mute button to cycle to the start of the menu, or the diagnostic menu will  
automatically exit after 6 seconds  
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6.4.3  
Diagnostic Menu for Software Version 7.00 & 7.21  
Display  
Description  
HC  
Humidity Compensation (HC) algorithm  
Invasive mode, compensation range is 0.0 to 3.0 °C ( CSP = 37.0 to 40 °C )  
Non-Invasive mode, compensation range is 0.0 to 5.0 °C ( CSP = 31.0 to 36.0 °C )  
By pressing the Mute and Mode buttons together for 1 second or pressing the Mute  
and Power buttons together for 1 second the user can respectively move up or  
down through the settings listed below. The humidifier will confirm the change with  
a double-beep.  
‘5.0’ = +5.0 °C of chamber compensation (Non-Invasive mode only)  
‘4.0’ = +4.0 °C of chamber compensation (Non-Invasive mode only)  
‘3.0’ = +3.0 °C of chamber compensation  
‘2.0’ = +2.0 °C of chamber compensation  
‘1.0’ = +1.0 °C of chamber compensation  
‘0.0’ = +0.0 °C of chamber compensation (No compensation)  
‘-A-‘ = Automatic humidity compensation mode:  
Invasive mode: 0 to 3 °C in 0.5 °C steps  
Non-invasive mode: 0 to 5 °C in 1 °C steps  
Chamber set point, in 0.1 °C resolution eg: 37.0  
Invasive mode range 35.5 to 40 °C.  
CSP  
Non-Invasive mode range 31.0 to 36.0 °C.  
Chamber Duty Cycle (%)  
Cdc  
CHP  
hP  
Chamber Power / Flow ratio (W/LPM)  
Heater Plate Temperature (1 °C)  
Flo  
Gas Flow Rate (0.1 LPM)  
“---“ = Unknown Flow (flow measurement not started)  
Gas Flow Rate Range:  
FLr  
“---“ = Unknown Flow (flow measurement not started)  
“no” = No flow  
“Lo” = Low flow, ( < 3 LPM )  
“In” = Intermediate flow, ( 2 to 17 LPM )  
“Hi” = High flow, ( > 13 LPM )  
“ -“ = Ventilated flow detected  
ASP  
Adc  
Cct  
Airway temperature set point (0.1 °C)  
Airway Duty Cycle (%)  
Connected Circuit heater identification:  
“S“ = Standard inspiratory heater connected  
“C” = Coaxial inspiratory heater connected  
“E” = Expiratory heater connected  
“---” = No heaters connected  
LAS  
LFS  
Last Alarm State, the display will blank, and the humidifier’s last alarm will be shown  
on the indicators. To clear LAS, press and hold the mute and mode buttons for 1  
second. The humidifier will beep when LAS has been cleared.  
Last Fault State, refer to section 6.3. To clear LFS, press and hold the mute and  
mode buttons for 1 second. The humidifier will beep when LFS has been cleared.  
SoF  
End  
Software version  
Press the mute button to cycle to the start of the menu, or the diagnostic menu will  
automatically exit after 6 seconds  
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6.4.4  
Diagnostic Menu for Software Version 7.14  
Display  
Description  
Humidity Compensation (HC) algorithm  
HC  
Note: HC is inactive while operating under non-heater wire control.  
Invasive mode, compensation range is 0.0 to 5.0 °C ( CSP = 37.0 to 42 °C )  
Non-Invasive mode, compensation range is 0.0 to 5.0 °C ( CSP = 31.0 to 36.0 °C )  
By pressing the Mute and Mode buttons together for 1 second or pressing the Mute and Power buttons  
together for 1 second the user can respectively move up or down through the settings listed below. The  
humidifier will confirm the change with a double-beep.  
‘5.0’ = +5.0 °C of chamber compensation  
‘4.0’ = +4.0 °C of chamber compensation  
‘3.0’ = +3.0 °C of chamber compensation  
‘2.0’ = +2.0 °C of chamber compensation  
‘1.0’ = +1.0 °C of chamber compensation  
‘0.0’ = +0.0 °C of chamber compensation (NO compensation)  
‘-A-‘ = Automatic humidity compensation mode:  
Invasive mode: 0 to 5 °C in 0.5 °C steps  
Non-invasive mode: 0 to 5 °C in 1 °C steps  
Connected breathing circuit identification:  
“S“ = Standard inspiratory heater connected  
“C” = Coaxial inspiratory heater connected  
“E” = Expiratory heater connected  
Cct  
“---” = No heaters detected while under heater wire control  
Chamber set point, in 0.1 °C resolution eg: 37.0  
Invasive mode range 35.5 to 42 °C.  
CSP  
Cdc  
Non-Invasive mode range 31.0 to 36.0 °C.  
Chamber Duty Cycle (%)  
During selection of this menu and while a chamber probe out test is active the chamber probe indicator will  
light.  
Chamber Power / Flow ratio (W/LPM)  
Heater Plate Temperature (1 °C)  
CHP  
hP  
Gas Flow Rate (0.1 LPM)  
Flo  
“---“ = Unknown Flow (flow measurement not started)  
Gas Flow Rate Range:  
FLr  
“---“ = Unknown Flow (flow measurement not started)  
“no” = No flow, ( Stand-by )  
“Lo” = Low flow, ( < 3 LPM )  
“In” = Intermediate flow, ( 2 to 17 LPM )  
“Hi” = High flow, ( > 13 LPM )  
“ -“ = Ventilated flow detected  
Airway temperature set point (0.1 °C)  
ASP  
Adc  
Airway Duty Cycle (%)  
During selection of this menu and while an airway probe out test is active the airway probe indicator will light.  
Water out number, used to detect the presence of chamber water, calculated from, chamber power / (heater  
plate temp. – chamber temp.).  
H2O  
During selection of this menu and while the water out number falls below a dry chamber threshold the water  
out indicator will light.  
Last Alarm State, the display will blank, and the humidifier’s last alarm will be shown on the indicators. To  
clear LAS, press and hold the mute and mode buttons for 1 second. The humidifier will beep when LAS has  
been cleared.  
LAS  
LFS  
Last Fault State, refer to section 6.3. To clear LFS, press and hold the mute and mode buttons for 1 second.  
The humidifier will beep when LFS has been cleared.  
Software version  
SoF  
End  
Press the mute button to cycle to the start of the menu, or the diagnostic menu will automatically exit after 6  
seconds.  
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6.4.5  
Diagnostic Menu for Software Version 7.22  
Display  
Description  
Humidity Compensation (HC) algorithm  
HC  
Note: HC is inactive while operating under non-heater wire control.  
Invasive mode, compensation range is 0.0 to 5.0 °C ( CSP = 37.0 to 42 °C )  
Non-Invasive mode, compensation range is 0.0 to 5.0 °C ( CSP = 31.0 to 36.0 °C )  
By pressing the Mute and Mode buttons together for 1 second or pressing the Mute and Power buttons  
together for 1 second the user can respectively move up or down through the settings listed below. The  
humidifier will confirm the change with a double-beep.  
‘5.0’ = +5.0 °C of chamber compensation  
‘4.0’ = +4.0 °C of chamber compensation  
‘3.0’ = +3.0 °C of chamber compensation  
‘2.0’ = +2.0 °C of chamber compensation  
‘1.0’ = +1.0 °C of chamber compensation  
‘0.0’ = +0.0 °C of chamber compensation (NO compensation)  
‘-A-‘ = Automatic humidity compensation mode:  
Invasive mode: 0 to 5 °C in 0.5 °C steps  
Non-invasive mode: 0 to 5 °C in 1 °C steps  
Connected breathing circuit identification:  
“S“ = Standard inspiratory heater connected  
“C” = Coaxial inspiratory heater connected  
“E” = Expiratory heater connected  
Cct  
“---” = No heaters detected while under heater wire control  
Non-Heater Wire Operation  
To enable non heater wire operation, press and hold both the mute and mode buttons simultaneously for 1  
second. The display will show ‘nhh’ and the humidifier will confirm with an audible beep. Ensure that no  
heated breathing circuit is connected to the humidifier otherwise the humidifier won’t change operation.  
To disable non-heater wire mode, repeat the above process or connect a heater breathing circuit.  
Chamber set point, in 0.1 °C resolution eg: 37.0  
Invasive mode range 35.5 to 42 °C.  
CSP  
Cdc  
Non-Invasive mode range 31.0 to 36.0 °C.  
Chamber Duty Cycle (%)  
During selection of this menu and while a chamber probe out test is active the chamber probe indicator will  
light.  
Chamber Power / Flow ratio (W/LPM)  
Heater Plate Temperature (1 °C)  
CHP  
hP  
Gas Flow Rate (0.1 LPM)  
Flo  
“---“ = Unknown Flow (flow measurement not started)  
Gas Flow Rate Range:  
FLr  
“---“ = Unknown Flow (flow measurement not started)  
“no” = No flow, ( Stand-by )  
“Lo” = Low flow, ( < 3 LPM )  
“In” = Intermediate flow, ( 2 to 17 LPM )  
“Hi” = High flow, ( > 13 LPM )  
“ -“ = Ventilated flow detected  
Airway temperature set point (0.1 °C)  
ASP  
Adc  
Airway Duty Cycle (%)  
During selection of this menu and while an airway probe out test is active the airway probe indicator will light.  
Water out number, used to detect the presence of chamber water, calculated from, chamber power / (heater  
plate temp. – chamber temp.).  
H2O  
During selection of this menu and while the water out number falls below a dry chamber threshold the water  
out indicator will light.  
Last Alarm State, the display will blank, and the humidifier’s last alarm will be shown on the indicators. To  
clear LAS, press and hold the mute and mode buttons for 1 second. The humidifier will beep when LAS has  
been cleared.  
LAS  
LFS  
Last Fault State, refer to section 6.3. To clear LFS, press and hold the mute and mode buttons for 1 second.  
The humidifier will beep when LFS has been cleared.  
Software version  
SoF  
End  
Press the mute button to cycle to the start of the menu, or the diagnostic menu will automatically exit after 6  
seconds.  
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6.4.6  
Diagnostic Menu for Software Version 7.23  
Display  
Description  
Cct  
Connected breathing circuit identification:  
“S“ = Standard inspiratory heater connected  
“C” = Coaxial inspiratory heater connected  
“E” = Expiratory heater connected  
“---” = No heaters detected while under heater wire control  
Non-Heater Wire Operation  
To enable non heater wire operation, press and hold both the mute and mode  
buttons simultaneously for 1 second. The display will show ‘nhh’ and the humidifier  
will confirm with an audible beep. Ensure that no heated breathing circuit is  
connected to the humidifier otherwise the humidifier won’t change operation.  
To disable non-heater wire mode, repeat the above process or connect a heater  
breathing circuit.  
CSP  
Chamber set point, in 0.1 °C resolution eg: 37.0  
Invasive mode: range 35.5 to 42 °C.  
Non-Invasive mode: range 31.0 to 36.0 °C.  
Chamber Duty Cycle (%)  
Cdc  
During selection of this menu and while a chamber probe out test is active the  
chamber probe indicator will light.  
CHP  
hP  
Chamber Power / Flow ratio (W/LPM)  
Heater Plate Temperature (1 °C)  
Gas Flow Rate (0.1 LPM)  
Flo  
“---“ = Unknown Flow (flow measurement not started)  
Gas Flow Rate Range:  
FLr  
“---“ = Unknown Flow (flow measurement not started)  
“no” = No flow, ( Stand-by )  
“Lo” = Low flow, ( < 3 LPM )  
“In” = Intermediate flow, ( 2 to 17 LPM )  
“Hi” = High flow, ( > 13 LPM )  
“ -“ = Ventilated flow detected  
ASP  
Adc  
Airway temperature set point (0.1 °C)  
Airway Duty Cycle (%)  
During selection of this menu and while an airway probe out test is active the airway  
probe indicator will light.  
H2O  
Water out number, used to detect the presence of chamber water, calculated from,  
chamber power / (heater plate temp. – chamber temp.).  
During selection of this menu the water out indicator will light if the water out  
number falls below a dry chamber threshold.  
LAS  
LFS  
Last Alarm State, the display will blank, and the humidifier’s last alarm will be shown  
on the indicators. To clear LAS, press and hold the mute and mode buttons for 1  
second. The humidifier will beep when LAS has been cleared.  
Last Fault State, refer to section 6.3. To clear LFS, press and hold the mute and  
mode buttons for 1 second. The humidifier will beep when LFS has been cleared.  
SoF  
End  
Software version  
Press the mute button to cycle to the start of the menu, or the diagnostic menu will  
automatically exit after 6 seconds.  
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7
Servicing Procedures  
7.1  
General Considerations  
WARNING:  
Although the MR850 display may not be illuminated, the unit may still be energized. Be  
sure to disconnect the MR850 from the power supply before servicing.  
All servicing procedures should be followed by a humidifier performance test, and an  
electrical safety test to ensure proper operation. The performance tests are outlined in  
section 8.  
CAUTION:  
Where screws and bolts have been removed from the product, do not use excessive force when  
re-fastening.  
Antistatic procedures should be followed when servicing this product.  
7.2  
Disassembly  
7.2.1  
Opening the case  
1. Ensure mains power is disconnected from the unit.  
2. Remove the four screws at the back of the humidifier.  
Separate the case by sliding the two halves apart. Pull the front half of the case away from  
the rear (Figure 7.1). The control PCB is attached to the front half of the case and is  
connected via ribbon cable to the power PCB fitted to the rear half of the case.  
Figure 7.1 Case separation  
3. Slide the power PCB forward with the side panel (the side panel is attached to the power  
PCB). The side panel will need to be pushed inwards during this action in order to unlatch  
and clear the electrical connectors.  
4. Un-clip the three fasteners (Figure 7.2) which hold the front (control) PCB to the front of the  
case, and separate the front PCB from the case.  
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Figure 7.2 Showing PCB fasteners  
7.2.2  
Replacing Fuses  
1. Open the case (section 7.2.1).  
2. The fuses can now be accessed. See Figure 7.3 for the location of the fuses on the power  
PCB.  
Figure 7.3 Showing location of the fuses on power PCB  
The four fuses have the following ratings:  
MR850 Model Number  
Supply Voltage  
Fuse Type  
Part Number  
999 830 001  
999 830 017  
999 830 009  
999 830 009  
999 830 001  
999 830 017  
999 830 012  
999 830 012  
MR850Axx  
230 V~  
F1: 1 A 250 V FastBlow  
F2: 4 A 125 V FastBlow  
F3: 2 A 250 V FastBlow  
F4: 2 A 250 V FastBlow  
F1: 1 A 250 V FastBlow  
F2: 4 A 125 V FastBlow  
F3: 3 A 250 V FastBlow  
F4: 3 A 250 V FastBlow  
MR850Pxx  
127 V~  
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MR850 Model Number  
Supply Voltage  
Fuse Type  
Part Number  
999 830 001  
999 830 017  
999 830 012  
999 830 012  
999 830 001  
999 830 017  
999 830 012  
999 830 012  
MR850Jxx  
115 V~  
F1: 1 A 250 V FastBlow  
F2: 4 A 125 V FastBlow  
F3: 3 A 250 V FastBlow  
F4: 3 A 250 V FastBlow  
F1: 1 A 250 V FastBlow  
F2: 4 A 125 V FastBlow  
F3: 3 A 250 V FastBlow  
F4: 3 A 250 V FastBlow  
MR850Gxx  
100 V~  
WARNING:  
Be sure to replace the fuse with the correct rating and type. Do not under any  
circumstances replace F2 with anything other than a fast blow fuse of the type and rating  
specified, as serious injury could result.  
3. Replace fuse.  
4. Close the case (section 7.2.8).  
7.2.3  
Replacement of Printed Circuit Boards (PCBs)  
1. Open the case (section 7.2.1).  
2. Disconnect all harnesses attached to the power PCB. Disconnect the mains and protective  
earth wires by unscrewing the terminal blocks, and cutting the cable ties (Figure 7.4).  
3. Remove PCBs, and using an appropriate tool, remove the ROM from the 32-pin socket on  
the control PCB. Store the ROM in an antistatic bag or box.  
4. Unpack replacement PCBs, install the ROM from the previous PCB.  
5. Replace the mains fuses (F3, F4) with the correct type, and attach mains and protective  
earth wires, using the cable ties provided (Figure 7.4).  
6. NOTE: If revision A PCBs are being replaced with revision C PCBs or later, (look for  
identification on the control board), then the wiring of the heater plate thermal cutout (and  
thermistor) will need to be changed. Un-clip the four pins from the connector by using a  
small flat bladed screwdriver. Re-wire the connector so the thermistor wires (white) are  
located on the inner two pins, and the thermal cutout wires (black) are located on the two  
outer pins.  
7. Connect harnesses from the transformer and heater plate to the power PCB.  
8. Close the case (section 7.2.8).  
9. Update the EEPROM software version (step 5, section 7.2.6).  
10. Check that the humidifier powers up normally, and complete a full performance test  
(section 8).  
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Figure 7.4 Showing Humidifier Power PCB wiring  
7.2.4  
Replacement of Transformer  
1. Open the case (section 7.2.1).  
2. Disconnect the transformer primary and secondary harnesses attached to the power PCB.  
3. Unscrew the four mounting screws fixing the transformer, and remove the transformer from  
the case.  
4. Place the new transformer inside the case, and mount using the four screws.  
5. Connect transformer primary and secondary harnesses to the power PCB.  
6. Close the case (section 7.2.8).  
7.2.5  
Servicing the Heater Plate  
Resetting the thermal cutout.  
1. Open the case (section 7.2.1).  
2. Check the thermal cutout on the heater plate by pushing the red button with a pen or small  
screwdriver - see Figure 7.5.  
Figure 7.5 Showing location of thermal cutout  
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3. If the thermal cutout "clicks" when pushed, it has been previously activated, and is now  
reset. NOTE: If the heater plate is still hot, it must be allowed to cool sufficiently before the  
thermal cutout will reset.  
4. Close the case (section 7.2.8).  
Replacing the heater plate thermistor  
NOTE: A Heater plate thermistor service kit is required. (Part Number: 043 041 254)  
1. Open the case (section 7.2.1).  
2. Disconnect the heater plate element, thermistor and thermal cutout harnesses attached to  
the power PCB.  
3. Remove the three screws holding the heater plate - see Figure 7.6.  
4. Cut cable ties attached to the heater plate harnesses.  
Figure 7.6 Showing location of Heater Plate screws  
5. Remove screw holding heater plate thermistor - see Figure 7.7.  
6. Unsolder the wires attached to the thermal cutout, and remove the old thermistor and  
harness.  
7. Place the new thermistor into position, and attach using the screw.  
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Figure 7.7 Showing location of Heater Plate Thermistor  
Thermal Cutout and Element Screws  
8. Solder the wires from the new harness to the heater plate thermal cutout.  
9. Attach the cable ties provided to the heater plate harness.  
10. Place heater plate back into position, ensuring the springs underneath the heater plate are  
in place. Attach to the humidifier's case using the three long screws that were previously  
removed.  
11. Connect the heater plate element, thermistor and thermal cutout harnesses to the power  
PCB.  
12. Close the case (section 7.2.8).  
Checking the heater plate element  
1. Open the case (section 7.2.1).  
2. Disconnect the heater plate element, thermistor and thermal cutout harnesses from the  
power PCB.  
3. Measure the resistance between the 2 contacts on the heater plate element connector (this  
is the large three pin connector).  
The resistance of the heater plate element should measure the same as outlined in the table  
below:  
MR850 Model Number  
MR850Axx  
Supply Voltage  
230 V~  
Heater Plate Resistance  
353 ± 12 Ohms  
108 ± 3 Ohms  
MR850Pxx  
127 V~  
MR850Jxx  
115 V~  
88 ± 3 Ohms  
MR850Gxx  
100 V~  
67 ± 2 Ohms  
If the measured resistance is outside this range, replace the heater plate element (steps 4 to 9).  
If the heater plate element is within specification, go to step 10.  
NOTE: If the heater plate element requires replacing, a heater plate element service kit is  
required - see Section 10. Spare Parts.  
4. Remove the two visible screws holding the heater plate element reflector. Remove the  
shield, making sure the washers are not lost. Unscrew the last four screws on the element  
cover (Figure 7.7).  
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5. Remove the heater element, leaving the mica insulator in place.  
6. Insert the new element into position, making sure the insulating mica is between the element  
and the heater plate.  
7. Replace the element cover, using the four screws that were previously removed.  
8. Replace the element reflector, making sure the washers that separate the reflector from the  
cover are placed back into position. Screw into place.  
9. Place the heater plate assembly back into position, ensuring the springs underneath the  
heater plate are in place. Attach to the humidifier case using the three long screws that  
were previously removed.  
10. Connect the heater plate element, thermistor and thermal cutout harnesses to the power  
PCB.  
11. Close the case (section 7.2.8).  
Replacing the Thermal Cutout  
1. Open the case (section 7.2.1).  
2. Disconnect the heater plate element, thermistor and thermal cutout harnesses from the  
power PCB.  
3. Remove the three screws holding the heater plate - see Figure 7.7.  
4. Un-solder the two black wires attached to the thermal cutout.  
5. Unscrew fasteners used to secure the thermal cutout, and remove.  
6. Place new thermal cutout in position and fasten using screws provided.  
7. Depress the thermal cutout's red button to ensure it is reset.  
8. Solder the black wires that were previously disconnected to the contacts on the new thermal  
cutout.  
9. Place heater plate back into position, ensuring the springs underneath the heater plate are  
in place. Attach to the humidifier's case using the three long screws that were previously  
removed.  
10. Connect the heater plate element, thermistor and thermal cutout harnesses to the power  
PCB.  
11. Close the case (section 7.2.8).  
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7.2.6  
Installing New Software  
NOTE: A software upgrade kit is required.  
Some software may not be available in your country. Refer to your local Fisher & Paykel  
Healthcare representative for the appropriate part number:  
Single ROM pack  
043042459  
32 ROM Pack  
043042461  
043042460  
043041255  
GJU model  
JHU model  
All other models  
043042458  
043042066  
Figure 7.8 Showing location of U3  
1. Open the case (section 7.2.1).  
2. Remove ROM integrated circuit U3 (Figure 7.8) using appropriate tools.  
3. Place new ROM into the empty socket, ensuring correct orientation.  
4. Close the case (section 7.2.8)  
5. Turn the humidifier upside down; use a non conducting tool to hold the production test  
button down. This button is accessible through the right air vent slot (when looking at the  
rear of the humidifier). See Figure 7.9.  
WARNING:  
Never use an electrically conducting tool to depress the production test button, as there  
are live mains voltages inside the humidifier.  
Figure 7.9 Showing Location of the Production Test Button  
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6. Apply mains power to the humidifier, while keeping the production test button depressed.  
The display should read: “PTS”. This ensures that the new software version number will be  
properly updated in the EEPROM.  
7. Turn off the mains power to the humidifier, and remove the tool.  
8. Check that the humidifier powers up normally, and complete a full performance test  
(section 8).  
(An alternative method for software versions 7.21 onward.)  
1. Perform steps 1 to 4 as above.  
2. Apply mains power to the humidifier. An error code E05 (EEPROM version is older than the  
ROM version) or E06 (EEPROM version is newer than the ROM version) will be given.  
Press the Mute button to confirm that the software is to be changed to the version in the  
ROM. Once the Mute button is pressed the software version is changed and the MR850 is  
automatically restarted.  
3. Complete a full performance test (section 8).  
7.2.7  
Replacing the Mains Cable  
1. Open the case (section 7.2.1).  
2. Unscrew the three mains cable wires from the terminal blocks on the power PCB (see  
Figure 7.4), and cut the cable tie on the PCB.  
3. Slide the mains cable retainer away from the rear of the case.  
4. Replace the power cord, and affix to the case by forcefully pushing the retainer back into  
position (towards the rear of the case).  
5. Attach the 3 mains cable wires to the terminal blocks on the power PCB (see table below for  
correct mains cable wiring), and attach the phase and neutral wires with a new cable tie.  
CORD TYPE  
USA / JAPAN  
(115 / 100 V~)  
EUROPEAN / IEC  
(230/ 127 V~)  
NZ / AUSTRALIA  
(230 V~)  
PHASE  
Black  
or Brown  
NEUTRAL  
White  
or Blue  
EARTH  
Green  
or Green/Yellow  
Brown  
Blue  
Green / Yellow  
Brown  
Blue  
Green / Yellow  
WARNING:  
When attaching the mains cable wires, ensure that the correct polarity of the mains  
wiring is followed. The table given above only applies to power cords supplied by Fisher  
& Paykel Healthcare.  
6. Close the case (section 7.2.8).  
7.2.8  
Closing the case  
1. Make sure that all harnesses that were previously disconnected have been reconnected. If  
the mains wiring was disconnected during servicing, check that the mains polarity is correct  
(see table in section 7.2.7).  
2. Slide the power PCB back into position, ensuring that the side panel slides in the slots and  
latches into the case rear.  
3. Place the control PCB back into position in the front of the case, ensuring all clips are  
located properly.  
4. Slide the case together, and replace the four screws.  
5. In order to check that the humidifier is working properly, complete a full performance test as  
outlined in section 8.  
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8
Performance Testing  
This section discusses the performance testing of the MR850 humidifier and also the MR850  
temperature / flow probe. Performance testing is required as part of ongoing maintenance or  
after servicing of the humidifier has been completed.  
8.1  
Humidifier Performance Testing  
If the humidifier has been operating normally, but a performance check is required as part of the  
maintenance schedule, it is recommended that the following tests are completed:  
1. A humidifier Calibration Check (Section 8.1.2)  
2. A humidifier Display Check (Section 8.1.3)  
However, if there is a problem with the humidifier, or if the humidifier has recently been  
serviced, then the following tests should be completed in addition to those outlined above.  
3. A humidifier Voltage Calibration Check (only required if the MR850's PCBs or mains  
transformer have been serviced or replaced). (Section 8.1.4)  
4. A humidifier Warm-up and Control Check. (Section 8.1.5)  
8.1.1  
Entering the Service Menu  
The MR850 humidifier has a special mode which enables the operator to verify correct  
operation. To enter this mode, hold down the power button on the front of the humidifier then  
apply mains power. The See-Manual indicator will light, and the humidifier will enter the service  
menu. The service menu has six different tests:  
Display  
-1-  
Description  
Reference  
Section 8.1.2  
Section 8.1.2  
Section 8.1.4  
Section 8.2.1  
Section 8.2.2  
Section 8.1.3  
Calibration Probe #1 Check  
Calibration Probe #2 Check  
Voltage Calibration Check  
Temperature Probe Check  
Flow Check  
-2-  
-3-  
-4-  
-5-  
-6-  
Display Test  
End  
Service Menu Exit  
Pushing the mute button while a number is displayed enters the relevant service test. When  
'End' is displayed the user can press the mute button to cycle back to the start of the service  
menu. If no button is pushed, the service menu will automatically exit after six seconds.  
NOTE: All tests performed in the service menu will automatically exit after 30 minutes.  
8.1.2  
Humidifier Calibration Check  
This section describes how to check the accuracy of the humidifier's temperature and flow  
measurement electronics.  
Equipment Required:  
•
•
MR850 Humidifier  
Reference Probe Set, Fisher & Paykel Healthcare part number: 900MR870  
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1. Hold down the power button, then apply mains power to the humidifier. This action places  
the humidifier into service mode.  
2. Select service mode number 1 (Calibration Probe #1 Check) by pushing the mute button  
when '-1-' is displayed.  
3. Insert the calibration probe with the GREY collet into the temperature / flow probe socket of  
the humidifier.  
4. Allow the display to stabilize for a few seconds, and check the number shown on the  
humidifier display. The table below shows the numbers displayed by the humidifier in this  
mode:  
TEST  
PASS  
100  
FAIL (LOW)  
101  
FAIL (HIGH)  
102  
Airway Temperature  
Chamber Temperature  
Flow Temperature  
Calibration Resistor  
Overheat  
100  
104  
108  
100  
110  
120  
100  
140  
180  
Heater Wire  
LED OFF  
Heater Wire  
LED ON  
Heater Wire  
LED ON  
If the humidifier displays any other value than '100' or if the heater wire indicator is on, check  
that you have the correct calibration probe plugged in, otherwise the MR850 PCBs are faulty  
and they will need to be serviced or replaced (refer 7.2.3).  
5. Press the power button (this causes the Calibration Probe #2 Check to be executed).  
6. Insert the calibration probe with a BLUE collet into the temperature / flow probe socket of the  
humidifier.  
7. Allow the displayed value to stabilize for a few seconds. Check the humidifier display. The  
table below shows the numbers displayed by the humidifier in this mode:  
TEST  
PASS  
200  
FAIL (LOW)  
201  
FAIL (HIGH)  
202  
Airway Temperature  
Chamber Temperature  
Flow Temperature  
Calibration Resistor  
Overheat  
200  
204  
208  
200  
210  
220  
200  
240  
280  
Heater Wire  
LED OFF  
Heater Wire  
LED ON  
Heater Wire  
LED ON  
If the humidifier displays any other value than '200' or if the heater wire indicator is on, check  
that you have the correct calibration probe plugged in, otherwise the MR850 PCBs are faulty  
and they will need to be serviced or replaced (refer 7.2.3).  
8. Remove the calibration probe, and press the mute button to exit service mode.  
8.1.3  
Humidifier Display Test  
This test is used to determine whether the humidifier's display is working correctly.  
1. Enter the service menu (refer section 8.1.1).  
2. Select service mode number 6 (Display test) by pushing the mute button when '-6-' is  
displayed.  
3. Check that all of the display LEDs and indicators are turned on.  
4. Push the mode button to change to a display cycle test. Check that all the LEDs and  
indicators light in sequence, and that there is only ever one LED on at a time.  
5. Push the Mute button to exit back to the service menu.  
If the humidifier does not pass the display test, then it is recommended that the humidifier PCBs  
are either replaced or sent for servicing (refer 7.2.3).  
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8.1.4  
Humidifier Voltage Calibration Check  
This check is required when the humidifier's PCBs have been serviced or replaced, or if the  
mains transformer has been replaced.  
Equipment Required:  
•
•
•
An AC voltmeter, capable of measuring RMS mains voltage to ±0.5 % accuracy.  
Suitable breathing circuit for MR850 (for example 900RT100).  
MR850 Heater Wire Adaptor (for example 900MR800).  
1. Connect a breathing circuit to the humidifier with the heater wire adaptor. Make sure the  
inspiratory limb is correctly plugged in, and that a temperature or calibration probe is not  
plugged in to the humidifier.  
2. Safely connect the AC voltmeter to the mains supply.  
NOTE: Connect the voltmeter in close proximity to the mains socket used to power the  
humidifier.  
3. Enter the service menu (refer section 8.1.1).  
4. Select service mode number 3 (Voltage Calibration Check) by pushing the mute button  
when '-3-' is displayed.  
5. Calculate the percentage of the actual mains voltage (the AC voltmeter reading) to the  
nominal mains voltage for the humidifier model being tested.  
NOTE: The nominal mains voltage is the voltage indicated on the left side of the humidifiers  
case, and will be either 230 V~, 127 V~, 115 V~, or 100 V~.  
Percentage mains = 100 x [Actual mains voltage (RMS) / Nominal Mains voltage]  
For example:  
MR850 Model AEK :  
Voltmeter Reading :  
Percentage mains:  
Nominal Mains Voltage is 230 V~  
240.5 V~  
100 x [240.5 / 230] = 104.5 %  
Round any decimal points: 105  
6. Adjust the reading on the humidifier's display to read the same as the value calculated  
above. This is achieved by pushing the mode button to increase, or the power button to  
decrease the percent value on the humidifier's display.  
7. Check that the mains voltage has remained constant. If necessary recalculate the  
percentage of actual mains voltage.  
8. Store the new value in the humidifier's memory by pushing and holding the mute and mode  
buttons together for 1 second. The humidifier will beep when the value has been correctly  
stored.  
9. Exit the voltage calibration test by pushing and holding down the mute button for longer than  
one second.  
8.1.5  
Humidifier Warm-up and Control Check  
This section describes how to check the humidifier's heater control systems. This test should  
be performed if there is a problem with the humidifier, or after servicing of the humidifier.  
Equipment Required:  
•
•
•
•
•
•
MR850 Humidifier  
MR850 Heater Wire Adaptor  
Flow/Temperature Probe  
Suitable breathing circuit for MR850 (for example: RT100)  
Suitable chamber for MR850 (for example: MR290) filled with water  
Gas supply - constant flow of: 10±5 SLPM (Standard Litres Per Minute)  
1. Make sure that the humidifier passes the calibration and display checks (refer 8.1.2 and  
8.1.3).  
2. Set up the humidifier as shown in section 4.1. Make sure the chamber probe is correctly  
inserted and invasive mode selected.  
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3. Connect the humidifier chamber inlet to the gas supply, and turn the humidifier on.  
4. Wait approximately 30 minutes for the humidifier to stabilise.  
Chamber and Airway temperatures can be checked by using the display mode (section 4.3.1)  
and set temperatures can be checked by using the diagnostic menu (section 6.4).  
After the humidifier has had time to warm up, the temperature at the airway and chamber should  
be within +0.3 to -1.8°C of their set point, with no alarms occurring.  
If any alarms do occur, refer to section 6 (troubleshooting), and determine the cause. If the  
temperatures displayed are out of range, then refer to the MR850 operating manual, and check  
the humidifier's setup.  
8.2  
Probe Accuracy Check  
A probe accuracy check is used to test for the correct operation of the temperature / flow probe.  
A Probe accuracy check consists of the following tests:  
1. Probe Temperature Accuracy Test (section 8.2.1)  
2. Probe Flow Accuracy Test (section 8.2.2)  
8.2.1  
Probe Temperature Accuracy Test  
This test is used to determine the temperature accuracy of the temperature/flow probes that are  
used with the MR850 humidifier.  
Equipment Required:  
•
•
•
•
MR850 Humidifier  
Flow/Temperature Probe  
Accurate Thermometer (Accuracy ± 0.5 degrees )  
Container of water at approximately 40 °C, or a stirred water bath at 40 °C.  
1. Perform a humidifier calibration test as outlined in section 8.1.2 to make sure the humidifier  
is reading temperature correctly (ignore this step if recently completed).  
2. Place both the airway and chamber probes in a container of water (at approx. 40 °C), along  
with the accurate thermometer.  
3. Make sure the water is constantly stirred, and wait approximately 30 seconds for the  
temperature to stabilise.  
4. Enter the service menu (refer section 8.1.1).  
5. Select service mode number 4 (Temperature Probe Check) by pushing the mute button  
when '-4-' is displayed.  
6. Plug the probe under test into the humidifier.  
NOTE: if a probe fault condition exists, the humidifier will alarm at this time.  
7. The chamber temperature will be displayed; pressing the mode button will toggle between  
the airway and chamber temperature.  
8. Compare the temperatures obtained with the thermometer. The temperature difference  
(between the humidifier temperatures and the thermometer) should not be greater than 1.5  
degrees. If the difference is larger than 1.5 °C, the probe should be replaced.  
8.2.2  
Probe Flow Accuracy Test  
This test is used to determine the flow accuracy of the temperature/flow probes that are used  
with the MR850 humidifier.  
Equipment Required:  
•
•
•
•
•
MR850 Humidifier  
Flow/Temperature Probe  
Suitable Breathing Circuit for MR850 (for example: 900RT100)  
Suitable Chamber for MR850 (for example: MR290)  
Gas supply - constant flow of: 10 ± 1 SLPM (Standard Litres Per Minute)  
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1. Perform a humidifier calibration check as outlined in section 8.1.2 (ignore this step if recently  
completed).  
2. Set up the humidifier as shown in Figure 4.1. Make sure the chamber probe is correctly  
inserted into the breathing circuit.  
3. Connect the humidifier chamber inlet to the gas supply.  
4. Enter the service menu (refer section 8.1.1).  
5. Select service mode number 5 (Flow Accuracy Check) by pushing the mute button when '-5-  
' is displayed.  
6. Plug the probe under test into the humidifier.  
NOTE: If a probe fault condition exists, the humidifier will alarm at this time.  
7. The humidifier will display '---' until a flow measurement has been acquired.  
8. Check that the flow measurement is between 5 and 15 LPM.  
9. If the flow measurement is outside this range, make sure there are no water drops or  
deposits on the temperature / flow probe's glass thermistor, and repeat test.  
10. If the flow measurement remains outside the specified range, the probe should be replaced.  
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9
Recommended Maintenance Checklist  
This sheet can be copied and used to keep a record of the maintenance procedures carried out  
on your MR850 Humidifier(s), and probes. Place the serial number and the date that the  
maintenance was carried out in the spaces provided. Refer to section 5 for a description of the  
maintenance procedures required.  
9.1  
Humidifier Check (Annually)  
Serial  
Number  
Visual Checks  
Performance  
Checks  
Electrical Safety  
Signature  
and Date  
1. Mains Cable 1. Calibration  
1. Earth Resistance  
2. Insulation Resistance  
3. Earth Leakage  
2. Heater Plate  
3. Heater Wire  
Adaptor  
Check  
2. Display Check  
4. Other tests as required  
9.2  
Probe Check (Every six months)  
Batch ID  
Visual Checks  
Performance Checks  
Signature  
and Date  
1. Check Glass Thermistor  
2. Check for Foreign Deposits  
3. Check Cable for Kinks, etc.  
4. Check Probe Connectors  
1. Temperature Accuracy  
2. Flow Accuracy  
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(Blank)  
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10 Spare Parts  
Should any parts of the humidifier require replacement, the following parts list is provided. Refer to the exploded  
diagram on the opposite page for part identification.  
Item  
1
Part Number  
043 041 247  
043 041 248  
043 042 575  
043 041 249  
Description  
100 V~ Heater Plate Assembly  
115 V~ Heater Plate Assembly  
127 V~ Heater Plate Assembly  
230 V~ Heater Plate Assembly  
2
3
662 040 058  
Heater Plate Spring  
043 042 068  
043 041 334  
043 042 067  
043 042 578  
Front Case Replacement kit – 115 V~ (J models )  
Front Case Replacement kit – 230 V~ (A models )  
Front Case Replacement kit – 100 V~ (G models )  
Front Case Replacement kit – 127 V~ (P models )  
4
5
6
336 060 143  
614 061 141  
Heater Plate Case Screw  
Transformer Mounting Screw  
043 042 267  
043 042 268  
043 042 269  
043 042 270  
043 042 271  
043 042 272  
043 042 273  
043 042 274  
043 042 275  
043 042 276  
043 042 277  
043 042 278  
043 042 454  
Rear case replacement kit – ADU model  
Rear case replacement kit – AEA model  
Rear case replacement kit – AEK model  
Rear case replacement kit – AEU model  
Rear case replacement kit – AFU model  
Rear case replacement kit – AGU model  
Rear case replacement kit – ALU model  
Rear case replacement kit – ANU model  
Rear case replacement kit – ARU model  
Rear case replacement kit – JHU model  
Rear case replacement kit – JSU model  
Rear case replacement kit – PEU model  
Rear case replacement kit – GJU model  
7
043 041 250  
621 040 524  
622 040 512  
693 041 483  
614 040 120  
Electronics PCB Assembly  
Mounting Tongue Nut  
Mounting Tongue Washer  
Mains Cable Collet  
8
9
10  
11  
12  
Case Screw  
095 428 322  
095 428 869  
095 428 317  
095 428 569  
095 428 323  
Mains Cord, USA Plug, Right Angle (115 V~)  
Mains Cord, USA Plug, Straight (100 V~)  
Mains Cord, NZ / Australian Plug (230 V~)  
Mains Cord, UK Plug (230 V~)  
Mains Cord, European Schuko Plug (230 V~)  
13  
693 041 482  
614 063 026  
Mounting Tongue  
14  
15  
Mounting Tongue Bolt  
043 041 304  
043 042 576  
043 041 305  
043 041 306  
Transformer : 230 V~  
Transformer : 127 V~  
Transformer : 115 V~  
Transformer : 100 V~  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
043 041 336  
693 041 487  
662 040 067  
341 040 560  
341 040 561  
341 040 559  
341 040 558  
693 040 783  
336 060 148  
693 041 486  
653 040 124  
Equipotential Stud Kit (Option)  
Finger guard MR850 blue  
Spring for finger guard  
Socket heater wire 4-way  
Socket temperature/flow probe 6-way  
Socket retaining ring yellow  
Socket retaining ring blue  
Side panel  
Plastic rivet  
Rubber button  
Button retaining ring  
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Heater Plate Assembly  
Item  
1
Part Number  
614 040 861  
641 040 829  
336 060 149  
641 040 707  
331040 114  
614 040 327  
614 040 117  
622 040 130  
095 428 320  
655 040 111  
349 040 052  
043 041 254  
614 040 327  
Description  
Screw (M4x12)  
2
Reflector  
3
Reflector Spacer Washers  
Element Cover  
4
5
Mica Insulator  
6
Thermistor Screw  
Earth Strap Screw  
Earth Strap Washer  
Earth Strap  
7
8
9
10  
11  
12  
13  
14  
Aluminium Heater Plate  
Thermal Cutout  
Thermistor Assembly Kit  
Thermal Cutout Screw  
043 041 251  
043 042 577  
043 041 252  
043 041 253  
Element Kit: 230 V~  
Element Kit: 127 V~  
Element Kit: 115 V~  
Element Kit: 100 V~  
15  
614 040 117  
Screw (M4x8)  
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11 Calibration Probe  
The information presented here refers to the construction of the MR850 Calibration Probe. This  
information is provided so that the probe can be checked for correct operation if required.  
The calibration probe consists of two Redel plugs, each containing four 0.1 % tolerance  
resistors. In order to measure the absolute accuracy of these resistors; it is recommended that  
an ohm meter with better than ± 0.2 % accuracy is used.  
To measure the value of the resistors used in the probes, unscrew the cable collet holding the  
plug together in order to gain access to the connector pins.  
Blue collet  
Grey collet  
Chamber temperature = 75.0 °C  
Airway temperature = 42.8 °C  
Chamber temperature = 55.2 °C  
Airway temperature = 40.5 °C  
The measured values must be accurate to + 0.3 % of their nominal value when using a meter  
accurate to ± 0.2 %.  
Contact a Fisher & Paykel Healthcare representative if an independent calibration probe check  
is required.  
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12 Serial Port & Logging Software  
12.1 INTRODUCTION  
The View850 software* is intended for use with the Fisher & Paykel Healthcare MR850  
Respiratory Humidifier. The software can be used to display humidifier data and log the results  
to a file. A serial cable, part number 900MR888*, is required in order to link the MR850  
humidifier to a PC.  
WARNING:  
The serial port must not be used when the humidifier is in patient use.  
Equipment connected to the serial -port must comply with the safety standard IEC60950  
for Personal Computers.  
No liability for consequential damage: In no event shall Fisher & Paykel Healthcare or its  
suppliers be liable for any damages arising out of the use of this View850 product.  
* View850 software is supplied on the MR850 Technical CD and can be ordered along with the  
900MR888 serial cable from Fisher and Paykel Healthcare.  
12.2 INSTALLATION  
Installing View850 software from the MR850 Technical CD.  
1. Insert CD into Personal Computer.  
2. Select ‘Install View850’ from menu list.  
3. Follow the install instructions.  
4. The software is now ready to run.  
12.3 OPERATING INSTRUCTIONS  
12.3.1 Viewing Humidifier Data  
Connect a 900MR888 serial cable* from the serial socket located on the bottom of the MR850  
to a communications port (RS-232) on the host computer. Run the View850.exe program from  
the Microsoft Windows Start Menu, Programs, View850.  
Set the correct com. port in the View850 software by going to the Config. Menu and clicking on  
Settings. The com. port can be changed within the Settings dialog box.  
Finally, start the program running by clicking on the `RUN' button. To stop, click the `Running'  
button.  
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12.3.2 Logging Humidifier Data to File  
The View850 software can log the data it receives to a text file. This text file can then be  
opened at a later date (by programs such as Microsoft Excel), in order to review humidifier  
performance.  
In order to log the humidifier data, first start the program running. Next set the directory you  
want the log files to be placed in, by using the menu buttons. Select a directory, and then click  
on the `OK' button.  
To start the program logging, click on the `Log Data to file' button. A log-file will be created.  
The name of the file will be the current time and date, followed by an `.850' extension. To stop,  
click the `Logging Data to File' button.  
The log rate (how often the data is saved to file) can be changed through the menu buttons.  
Note: For further information on this program, view the ‘Readme.txt’ file.  
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13 EMC INFORMATION  
WARNING:  
The use of accessories other than those specified by Fisher & Paykel Healthcare may  
result in increased emissions or decreased immunity of the equipment or system.  
Guidance and manufacturer’s declaration – electromagnetic emissions  
The MR850 is intended for use in the electromagnetic environment specified below. The customer or the user of the MR850 should  
assure that it is used in such an environment.  
Emissions test  
Compliance  
Electromagnetic environment - guidance  
RF emissions CISPR 11  
Group 1  
The MR850 uses RF energy only for its internal function.  
Therefore, its RF emissions are very low and are not likely to  
cause any interference in nearby electronic equipment.  
RF emissions CISPR 11  
Harmonic emissions  
IEC 61000-3-2  
Class B  
Class B  
The MR850 is suitable for use in all establishments, including  
domestic establishments and those directly connected to the  
public low-voltage power supply network that supplies buildings  
used for domestic purposes.  
Voltage fluctuations/ flicker emissions  
IEC 61000-3-3  
Complies  
Guidance and manufacturer’s declaration – electromagnetic emissions  
The MR850 is intended for use in the electromagnetic environment specified below. The customer or the user of the MR850 should  
assure that it is used in such an environment.  
Emissions test  
IEC 60601-1 test level  
6 kV contact  
Compliance level  
6 kV contact  
8 kV air  
Electromagnetic environment - guidance  
Electrostatic discharge  
(ESD)  
Floors should be wood, concrete or ceramic  
tile. If floors are covered with synthetic  
material, the relative humidity should be at  
least 30 %.  
8 kV air  
IEC 61000-4-2  
Electrical fast  
transient/burst  
Mains power quality should be that of a  
typical commercial or hospital environment.  
2 kV for power supply  
lines  
2 kV for power supply  
lines  
IEC 61000-4-4  
1 kV for input/output lines  
1 kV differential mode  
2 kV common mode  
1 kV differential mode  
2 kV common mode  
1 kV for input/output lines  
1 kV differential mode  
2 kV common mode  
1 kV differential mode  
2 kV common mode  
Surge  
Mains power quality should be that of a  
typical commercial or hospital environment.  
IEC 61000-4-5  
Surge  
Mains power quality should be that of a  
typical commercial or hospital environment.  
IEC 61000-4-5  
Voltage dips, short  
interruptions and voltage  
variations on power supply  
input lines  
< 5 % UT (> 95 % dip in UT)  
for 0,5 cycle  
< 5 % UT (> 95 % dip in UT)  
for 0,5 cycle  
Mains power quality should be that of a  
typical commercial or hospital environment.  
If the user of the MR850 requires continued  
operation during power mains interruptions,  
it is recommended that the MR850 be  
powered from an uninterruptible power  
supply or a battery.  
40 % UT (60 % dip in UT)  
for 5 cycles  
40 % UT (60 % dip in UT)  
for 5 cycles  
IEC 61000-4-11  
70 % UT (30 % dip in UT)  
for 25 cycles  
70 % UT (30 % dip in UT)  
for 25 cycles  
< 5 % UT (> 95 % dip in UT)  
< 5 % UT (> 95 % dip in UT)  
for 5 sec  
for 5 sec  
Power frequency (50/60  
Hz) magnetic field  
3 A/m  
3 A/m  
Power frequency magnetic fields should be  
at levels characteristic of a typical location in  
a typical commercial or hospital  
environment.  
IEC 61000-4-8  
NOTE UT is the a.c. mains voltage prior to application of the test level.  
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Guidance and manufacturer’s declaration – electromagnetic immunity  
The MR850 is intended for use in the electromagnetic environment specified below. The customer or the user of the MR850 should  
assure that it is used in such an environment.  
Immunity test  
IEC 60601 test level  
Compliance  
level  
Electromagnetic environment – guidance  
Portable and mobile RF communications equipment should be used  
no closer to any part of the MR850 including cables, than the  
recommended separation distance calculated from the equation  
applicable to the frequency of the transmitter.  
Recommended separation distance  
Conducted RF  
IEC 61000-4-6  
Radiated RF  
3 Vrms  
3 V  
d = 1,2√P  
150 kHz to 80 MHz  
3 V/m  
3 V/m  
d = 1,2√P  
d = 2,3√P  
80 MHz to 800 MHz  
800 MHz to 2.5 GHz  
IEC 61000-4-3  
80 MHz to 2,5 GHz  
where P is the maximum output power rating of the transmitter in  
watts (W) according to the transmitter manufacturer and d is the  
recommended separation distance in metres (m).  
Field strengths from fixed RF transmitters, as determined by an  
electromagnetic site survey a ,should be less than the compliance  
level in each frequency range b.  
Interference may occur in the vicinity of equipment marked with the  
following symbol:  
NOTE 1 At 80 MHz and 800 MHz, the higher frequency range applies.  
NOTE 2 These guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption and reflection from  
structures, objects and people.  
a
Field strengths from fixed transmitters, such as base stations for radio (cellular/cordless) telephones and land mobile radios,  
amateur radio, AM and FM radio broadcast and TV broadcast cannot be predicted theoretically with accuracy. To assess the  
electromagnetic environment due to fixed RF transmitters, an electromagnetic site survey should be considered. If the measured  
field strength in the location in which the MR850 is used exceeds the applicable RF compliance level above, the MR850 should be  
observed to verify normal operation. If abnormal performance is observed, additional measures may be necessary, such as  
reorienting or relocating the MR850.  
b
Over the frequency range 150 kHz to 80 MHz, field strengths should be less than 3 V/m.  
Recommended separation distances between portable and mobile RF communications equipment  
and the MR850  
The MR850 is intended for use in an electromagnetic environment in which radiated RF disturbances are controlled. The customer  
or the user of the MR850 can help prevent electromagnetic interference by maintaining a minimum distance between portable and  
mobile RF communications equipment (transmitters) and the MR850 as recommended below, according to the maximum output  
power of the communications equipment.  
Separation distance according to frequency of transmitter (m)  
Rated maximum output  
power of transmitter (W)  
150 kHz to 80 MHz  
80 MHz to 800 MHz  
800 MHz to 2,5 GHz  
D = 1,2√P  
0,12  
0,38  
1,2  
D = 1,2√P  
0,12  
0,38  
1,2  
D = 2,3√P  
0,23  
0,73  
2,3  
0,01  
0,1  
1
10  
3,8  
3,8  
7,3  
100  
12  
12  
23  
For transmitters rated at a maximum output power not listed above, the recommended separation distance d in metres (m) can be  
estimated using the equation applicable to the frequency of the transmitter, where P is the maximum output power rating of the  
transmitter in watts (W) according to the transmitter manufacturer.  
NOTE 1 At 80 MHz and 800 MHz, the separation distance for the higher frequency range applies.  
NOTE 2 These guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption and reflection from  
structures, objects and people.  
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14 Product Change History  
Due to upgrades performed on delivered MR850 Respiratory Humidifiers, software and  
hardware versions are listed below.  
It should be realised that possible future upgrades may change the operation of the Humidifier.  
Please note that software Versions 4.40 and 4.44 will only work with Revision A or B PCB’s and  
Version 5.12 or later will only work with Revision C, D or E PCB’s.  
History Change for model JHU  
PCB  
Version  
Software  
Version  
Introduction  
Serial Number  
Comments  
A
A
C
4.40  
4.44  
5.12  
19 September 1998 9885xxx00000  
22 October 1998  
First production release.  
Software upgrade.  
12 April 1999  
9985xxx00053  
Release of new PCB to  
accommodate change in  
temperature probe circuit  
redesign.  
C
D
5.13  
5.13  
5 May 1999  
Software upgrade.  
14 January 2000  
2000-85xxx00028  
2000-85xxx01661  
2000-85xxx02806  
Release of new PCB to improve  
manufacture.  
D
D
5.23  
5.33  
3 April 2000  
25 July 2000  
Software upgrade for low flow  
control stability.  
Software upgrade, allowing  
Neonatal volume ventilation  
capability. Manual Temperature  
Compensation (TC)  
implemented.  
D
5.34  
11 October 2000  
2000-85xxx04212  
Software upgrade to improve  
EMI immunity.  
D
D
5.45  
7.00  
19 February 2001  
2 April 2002  
2001-85xxx00427  
2002-85xxx00976  
Software upgrade.  
Software upgrade.  
Improve HC speed in Non-  
invasive mode.  
F&P Co-axial circuit recognition  
and control.  
D
D
5.70  
7.23  
14 April 2003  
31 May 2004  
2003-85JHU008266  
2004-85JHU006084  
Software release USA only.  
Added Non-heater wire  
operation.  
PTS access through serial  
command.  
Humidifier model protection.  
Remove HC.  
Software release USA only.  
E
7.23  
5 July 2004  
2004-85JHU008300  
Release of new PCB capable of  
selective soldering.  
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History Change for model GJU  
PCB  
Version  
Software  
Version  
Introduction  
Serial Number  
Comments  
A
A
C
4.40  
4.44  
5.12  
19 September 1998 9885xxx00000  
22 October 1998  
First production release.  
Software upgrade.  
12 April 1999  
9985xxx00053  
Release of new PCB to  
accommodate change in  
temperature probe circuit  
redesign.  
C
D
5.13  
5.13  
5 May 1999  
Software upgrade.  
14 January 2000  
2000-85xxx00028  
2000-85xxx01661  
2000-85xxx02806  
Release of new PCB to  
improve manufacture.  
D
D
5.23  
5.33  
3 April 2000  
25 July 2000  
Software upgrade for low flow  
control stability.  
Software upgrade, allowing  
Neonatal volume ventilation  
capability. Manual  
Temperature Compensation  
(TC) implemented.  
D
5.34  
11 October 2000  
19 February 2001  
2000-85xxx04212  
2001-85xxx00427  
Software upgrade to improve  
EMI immunity.  
D
D
5.45  
6.00  
Software upgrade.  
15 November 2001 Only released as  
Software upgrade.  
software upgrade  
kits.  
Introduction of the automatic  
and manual Humidity  
Compensation (HC) mode.  
Added time delay to the OFF  
button. Enable low  
temperature alarm in stand-by.  
D
7.00  
2 April 2002  
2002-85xxx00976  
Software upgrade.  
Improve HC speed in Non-  
invasive mode.  
F&P Co-axial circuit  
recognition and control.  
D
D
7.20  
7.21  
18 March 2004  
9 June 2004  
2004-85GJU002592  
2004-85GJU006775  
Software upgrade.  
Software upgrade.  
PTS access through serial  
command.  
Humidifier model protection.  
Software release Japan only.  
E
7.21  
9 July 2004  
2004-85GJU008765  
Release of new PCB capable  
of selective soldering.  
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History Change for all model except JHU & GJU  
PCB  
Version  
Software  
Version  
Introduction  
Serial Number  
Comments  
A
A
C
4.40  
4.44  
5.12  
19 September 1998 9885xxx00000  
22 October 1998  
First production release.  
Software upgrade.  
12 April 1999  
9985xxx00053  
Release of new PCB to  
accommodate change in  
temperature probe circuit  
redesign.  
C
D
5.13  
5.13  
5 May 1999  
Software upgrade.  
14 January 2000  
2000-85xxx00028  
2000-85xxx01661  
2000-85xxx02806  
Release of new PCB to  
improve manufacture.  
D
D
5.23  
5.33  
3 April 2000  
25 July 2000  
Software upgrade for low flow  
control stability.  
Software upgrade, allowing  
Neonatal volume ventilation  
capability. Manual  
Temperature Compensation  
(TC) implemented.  
D
5.34  
11 October 2000  
19 February 2001  
2000-85xxx04212  
2001-85xxx00427  
Software upgrade to improve  
EMI immunity.  
D
D
5.45  
6.00  
Software upgrade.  
15 November 2001 Only released as  
software upgrade kits.  
Software upgrade.  
Introduction of the automatic  
and manual Humidity  
Compensation (HC) mode.  
Added time delay to the OFF  
button. Enable low  
temperature alarm in stand-by.  
D
D
7.00  
7.14  
2 April 2002  
2002-85xxx00976  
2003-85xxx009621  
Software upgrade.  
Improve HC speed in Non-  
invasive mode.  
F&P Co-axial circuit  
recognition and control.  
22 April 2003  
Software upgrade.  
Auto HC increased to +5 °C.  
Diagnostic menu changes.  
Added Non-heater wire  
operation.  
D
D
7.17  
7.22  
31 July 2003  
28 May 2004  
2003-85xxx013518  
2004-85xxx006024  
Software upgrade.  
PTS access through serial  
command.  
Humidifier model protection.  
E
7.22  
2 July 2004  
2004-85xxx008200  
Release of new PCB capable  
of selective soldering.  
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