38AU
Air Cooled Condensing Units
60 Hz
With PuronR (R---410A) Refrigerant
S i z e s 1 6 --- 2 5
Installation, Start---Up and
Service Instructions
CONTENTS
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . 2
Compressor Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Servicing Systems on Roofs with
Synthetic Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
INSTALLATION GUIDELINES . . . . . . . . . . . . . . . . . . 2
Replacement/Retrofit — R-22 to Puron . . . . . . . . . . . 2
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 11 - 22
Liquid Line Filter Drier . . . . . . . . . . . . . . . . . . . . . . . 34
Field Refrigerant Access Ports . . . . . . . . . . . . . . . . . . 34
Factory High-Flow Access Ports . . . . . . . . . . . . . . . . 34
Comfort Alert Diagnostic Module . . . . . . . . . . . . . . . 35
Compressor Protection . . . . . . . . . . . . . . . . . . . . . . . . 37
Crankcase Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Low-Pressure Switch . . . . . . . . . . . . . . . . . . . . . . . . . 37
High-Pressure Switch . . . . . . . . . . . . . . . . . . . . . . . . . 37
Outdoor Fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Coil Type Identification . . . . . . . . . . . . . . . . . . . . . . . 42
NOVATIONtCoil Cleaning and Maintenance . . . . . 42
Repairing NOVATION Condenser Tube Leaks . . . . . 42
Replacing NOVATION Condenser Coil . . . . . . . . . . . 43
Jobsite Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Step 1 - Plan for Unit Location . . . . . . . . . . . . . . . . . 11
Step 2 - Complete Pre-Installation Checks . . . . . . . . 11
Step 3 – Prepare Unit Mounting Support . . . . . . . . . . 12
Step 4 – Rig and Mount the Unit . . . . . . . . . . . . . . . . 12
Step 5 – Complete Refrigerant Piping Connections . . . 12
Step 6 – Install Accessories . . . . . . . . . . . . . . . . . . . . 17
Step 7 – Complete Electrical Connections . . . . . . . . . 18
PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Turn On Crankcase Heater . . . . . . . . . . . . . . . . . . . . . 23
Preliminary Charge . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Routine Cleaning of Round-Tube Plate Fin
(RTPF) Coils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 - 31
Preliminary Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Start Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Fastener Torque Values . . . . . . . . . . . . . . . . . . . . . . . . 44
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . 44 - 45
OPERATING SEQUENCE . . . . . . . . . . . . . . . . . . . . . . 32
APPENDIX A
Indoor (Supply) Fan . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Cooling, Unit Without Economizer . . . . . . . . . . . . . . 32
Cooling, Unit With Economizer . . . . . . . . . . . . . . . . . 32
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Air Conditioner & Heat Pump with PuronR
—
Quick Reference Guide . . . . . . . . . . . . . . . . . . . . . . . . . 46
APPENDIX B
Wiring Diagram List . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
ROUTINE SYSTEM MAINTENANCE . . . . . . . . . . . . 33
APPENDIX C
Low Ambient Option — Factory Installed . . . . . . . . . . 47
Quarterly Inspection (and 30 days after initial start) . . . 33
Seasonal Maintenance . . . . . . . . . . . . . . . . . . . . . . . . 33
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . 55 - 56
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 - 44
Refrigeration System . . . . . . . . . . . . . . . . . . . . . . . . . 33
1
Same tube sizes are capable of handling higher flowrates
(expressed as tons of cooling capacity) with Puron
refrigerant compared to R-22 at constant pressure drops.
For example, a 1/2-inch OD liquid line is rated at 33%
higher tons with PuronR than with R-22 (at 5_F pressure
drop). A 1 1/8-inch OD suction line is rated at 53% higher
tons with Puron than with R-22 (at 2_F pressure drop).
Refrigeration lines selected for R-22 use are typically
oversized for Puron applications. Carefully check the
existing suction line size against the table for maximum size
(see Table 7); replace vertical riser segments if necessary.
Check existing liquid line size against sizing data in Table 5
or 6; replace with smaller lines when feasible.
5. Install a new field-supplied liquid-line filter drier at
the indoor coil just upstream of the TXV or fix orifice
metering device.
6. If a suction line filter drier is also to be installed, in-
stall suction line drier downstream of suction line ser-
vice valve at condensing unit.
!
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
Never install suction-line filter drier in the liquid-line
of a PuronR system.
Installation –
1. Remove the existing evaporator coil or fan coil and
install the replacement coil when appropriate.
2. Drain oil from low points and traps in suction line
tubing (and hot gas bypass tubing if appropriate) and
evaporator if they were not replaced. Removing oil
from evaporator coil may require purging of the
tubing with dry nitrogen.
3. Unless indoor unit is equipped with a Puron® ap-
proved metering device, change the metering device
to a thermal expansion valve (TXV) designed for
PuronR (R-410A).
4. Remove the existing outdoor unit. Install the new out-
door unit according to these installation instructions.
7. If required, install a 100% activated alumina suction
line filter drier at the outdoor unit.
8. Evacuate and charge the system according to the in-
structions in this installation manual.
9. Operate the system for 10 hr. Monitor the pressure
drop across the suction line filter drier. If pressure
drop exceeds 3 psig (21kPa), replace suction-line and
liquid-line filter driers. Be sure to purge system with
dry nitrogen and evacuate when replacing filter
driers. Continue to monitor the pressure drop across
suction-line filter drier. Repeat filter changes is neces-
sary. Never leave suction-line filter drier in system
longer than 72 hr (actual time).
3
C10942
Standard
Weight
Corner
A
Corner
B
Corner
C
Corner
D
Unit
Height
UNIT
Center of Gravity
lbs.
633
kg.
lbs.
kg.
lbs.
kg.
61
lbs.
kg.
61
lbs.
kg.
X
Y
Z
H
3
38AUZ*16
(MCHX)
38
[965.2]
19
[482.6]
15
[381]
50
/
8
288
220
220
237
237
100
134
134
172
172
135
135
135
135
144 65.5
144 65.5
[1279.2]
3
38AUD*16
(MCHX)
38
[965.2]
19
[482.6]
15
[381]
50
/
8
633
731
731
288
332
332
100
107
107
61
78
78
61
61
61
[1279.2]
3
38AUZ*16
(RTPF)
38
[965.2]
19
[482.6]
17
[431.8]
50
/
8
186
186
84
84
[1279.2]
3
38AUD*16
(RTPF)
38
[965.2]
19
[482.6]
17
[431.8]
50
/
8
[1279.2]
LEGEND: MCXH = Novation™ coil
RTPF = Round Tube/Plate Fin coil
Fig. 1 - 38AU**16 Unit Dimensions
4
C10943
Standard
Weight
Corner
A
Corner
B
Corner
C
Corner
D
Unit
Height
UNIT
Center of Gravity
lbs.
978
kg.
lbs.
kg.
lbs.
kg.
85
lbs.
kg.
67
lbs.
kg.
X
Y
Z
H
3
38AUZ*25
(RTPF)
38
[965.2]
23
[584.2]
17
[431.8]
50 /
8
444
360
360
163
188
188
147
147
283
283
128
[1279.2]
3
38AUD*25
(RTPF)
38
[965.2]
23
[584.2]
17
[431.8]
50 /
8
978
444
163
85
67
128
[1279.2]
LEGEND: RTPF = Round Tube/Plate Fin coil
Fig. 2 - 38AU**25 Unit Dimensions
5
Table 1A — Physical Data — 38AUZ*16-25 Units — 60 Hz English
UNIT SIZE 38AU
Z*16
Z*25
NOMINAL CAPACITY (tons)
OPERATING WEIGHTS (lb)
NOVATION™ Coil (Al Tube)
Round Tube/Plate Fin Coil (Cu/Al)
15
20
633
731
---
900
‡
REFRIGERANT TYPE
R-410A
†
NOVATION Operating Charge, Typical (lb)
NOVATION Shipping Charge (lb)
24.6
12.2
43.0
32.0
---
---
†
RTPF Operating Charge, Typical (lb)
38.0
28.0
RTPF Shipping Charge (lb)
COMPRESSOR
Qty...Type
2...Scroll
60
2...Scroll
110
Oil Charge (oz)
CONDENSER FANS
Qty...Rpm
3...1100
1
4...1100
1
Motor Hp
/
/
4
4
Diameter
22
22
Nominal Airflow (Cfm Total)
Watts (Total)
9,000
970
12,000
1150
RTPF CONDENSER COIL
Material (Tube/Fin)
Coil Type
Cu / Al
Cu / Al
3
3
/ --- in R T P F
8
/ --- in R T P F
8
Rows/Fins per inch (FPI)
Face Area (sq ft total)
NOVATION CONDENSER COIL
Material (Tube/Fin)
Coil Type
2 / 17
47.0
2 / 17
50.0
Al / Al
Novation
1 / 17
---
---
---
---
Rows/Fins per inch (FPI)
Face Area (sq ft total)
CONTROLS
50.0
Pressurestat Settings (psig)
High Cutout
630 ± 10
505 ± 20
54 ± 3
Cut-in
Low Cutout
Cut-in
117 ± 5
PIPING CONNECTIONS (in. ODS)
Qty...Suction
3
5
1...1 /
1...1 /
5
8
8
5
Qty...Liquid
1... /
1... /
8
8
LEGEND
RTPF — Round Tube/Plate Fin
ODS — Outside Diameter Sweat (socket)
‡
†
Unit is factory-supplied with partial charge only.
Typical operating charge with 25 ft of interconnecting piping.
6
Table 1B — Physical Data — 38AUZ*16-25 Units — 60 Hz SI
UNIT SIZE 38AU
Z*16
Z*25
NOMINAL CAPACITY (kW)
OPERATING WEIGHT (kg)
NOVATION™ Coil (Al Tube)
Round Tube/Plate Fin Coil (Cu/Al)
52.7
70.3
288
332
---
409
‡
REFRIGERANT TYPE
R-410A
Scroll
†
NOVATION Operating Charge, Typical (kg)
NOVATION Shipping Charge (kg)
11.1
5.4
---
---
†
RTPF Operating Charge, Typical (kg)
19.5
14.5
17.2
12.7
RTPF Shipping Charge (kg)
COMPRESSOR
Qty...Type
2...Scroll
1.7
2...Scroll
3.2
Oil Charge (L)
CONDENSER FANS
Qty...r/s
3...18
1
4...18
1
Motor Hp NEMA
/
/
4
4
Diameter (mm)
560
4248
970
560
5663
1150
Nominal Airflow (L/s)
Watts (Total)
RTPF CONDENSER COIL (Qty)
Material (Tube/Fin)
Coil Type
Cu / Al
Cu / Al
3
3
/ --- in R T P F
8
/ --- in R T P F
8
Rows/Fins per Meter (Fins/m)
Face Area (sq m total)
NOVATION CONDENSER COIL
Material (Tube/Fin)
Coil Type
1...670
4.4
2...670
4.6
Al / Al
Novation
1...670
4.6
---
---
---
---
Rows/Fins per Meter (Fins/m)
Face Area (sq m total)
CONTROLS
Pressurestat Settings (kPa)
High Cutout
4347 ± 70
3482 ±138
372 ± 21
807 ± 34
Cut-in
Low Cutout
Cut-in
PIPING CONNECTIONS (mm ODS)
Qty...Suction
1...34.9
1...13.3
1...38.7
1...13.3
Qty...Liquid
LEGEND
RTPF — Round Tube/Plate Fin
NEMA — National Electrical Manufacturers Association
ODS — Outside Diameter Sweat (socket)
‡
†
Unit is factory-supplied with partial charge only.
Typical operating charge with 7.62 m of interconnecting piping.
7
Table 2A — Physical Data — 38AUD*16-25 Units — 60 Hz English
UNIT SIZE 38AU
D*16
D*25
NOMINAL CAPACITY (tons)
OPERATING WEIGHTS (lb)
NOVATION™ Coil (Al Tube)
Round Tube/Plate Fin Coil (Cu/Al)
15
20
633
731
---
900
‡
REFRIGERANT TYPE
R-410A
†
NOVATION Operating Charge A/B, Typical (lb)
NOVATION Shipping Charge A/B (lb)
12.0 / 12.0
6.0 / 6.0
---
---
†
RTPF Operating Charge A/B, Typical (lb)
22.0 / 22.0
16.0 / 16.0
19.0 / 19.0
14.0 / 14.0
RTPF Shipping Charge A/B (lb)
COMPRESSOR
Qty...Type
2...Scroll
60 / 60
2...Scroll
110 / 110
Oil Charge A/B (oz)
CONDENSER FANS
Qty...Rpm
3...1100
4...1100
1
1
Motor Hp
/4
/
4
Diameter
22
22
Nominal Airflow (Cfm Total)
Watts (Total)
9,000
970
12,000
1150
RTPF CONDENSER COIL
Material (Tube/Fin)
Coil Type
Cu / Al
Cu / Al
3
3
/ --- in R T P F
8
/ --- in R T P F
8
Face Area (sq ft total)
Rows/Fins per inch (FPI)
NOVATION CONDENSER COIL
Material (Tube/Fin)
Coil Type
47
50
2 / 17
2 / 17
Al / Al
Novation
50
---
---
---
---
Face Area (sq ft total)
Rows/Fins per inch (FPI)
CONTROLS
1 / 17
Pressurestat Settings (psig)
High Cutout
630 ± 10
505 ± 20
54 ± 3
Cut-in
Low Cutout
Cut-in
117 ± 5
PIPING CONNECTIONS (in. ODS)
Qty...Suction
3
3
2...1 /
2...1 /
1
8
8
1
Qty...Liquid
2... /
2... /
2
2
LEGEND
RTPF — Round Tube/Plate Fin
ODS — Outside Diameter Sweat (socket)
‡
†
Unit is factory-supplied with partial charge only.
Typical operating charge with 25 ft of interconnecting piping.
8
Table 2B — Physical Data — 38AUD*16-25 Units — 60 Hz SI
UNIT SIZE 38AU
D*16
D*25
NOMINAL CAPACITY (kW)
OPERATING WEIGHT (kg)
NOVATION™ Coil (Al Tube)
Round Tube/Plate Fin Coil (Cu/Al)
52.7
70.3
288
332
---
409
‡
REFRIGERANT TYPE
R-410A
5.4 / 5.4
2.7 / 2.7
10.0 / 10.0
7.3 / 7.3
R-410A
---
†
NOVATION Operating Charge A/B, Typical (kg)
NOVATION Shipping Charge A/B (kg)
---
†
RTPF Operating Charge A/B, Typical (kg)
8.6 / 8.6
6.8 / 6.8
RTPF Shipping Charge A/B (kg)
COMPRESSOR
Qty...Type
2...Scroll
1.7 / 1.7
2...Scroll
3.2 / 3.2
Oil Charge A/B (L)
CONDENSER FANS
Qty...r/s
3...18
1
4...18
1
Motor Hp NEMA
/
/
4
4
Diameter (mm)
560
4248
970
560
5663
1150
Nominal Airflow (L/s)
Watts (Total)
RTPF CONDENSER COIL (Qty)
Material (Tube/Fin)
Coil Type
Cu / Al
Cu / Al
3
3
/ --- in R T P F
8
/ --- in R T P F
8
Rows/Fins per Meter (Fins/m)
Face Area (sq m total)
NOVATION CONDENSER COIL
Material (Tube/Fin)
Coil Type
1...670
4.4
2...670
4.6
Al / Al
Novation
1...670
4.6
---
---
---
---
Rows/Fins per Meter (Fins/m)
Face Area (sq m total)
CONTROLS
Pressurestat Settings (kPa)
High Cutout
4347 ± 70
3482 ±138
372 ± 21
807 ± 34
4347 ± 70
3482 ±138
372 ± 21
807 ± 34
Cut-in
Low Cutout
Cut-in
PIPING CONNECTIONS (mm ODS)
Qty...Suction
2...34.9
2...12.7
2...34.9
2...12.7
Qty...Liquid
LEGEND
RTPF — Round Tube/Plate Fin
NEMA — National Electrical Manufacturers Association
ODS — Outside Diameter Sweat (socket)
‡
†
Unit is factory-supplied with partial charge only.
Typical operating charge with 7.62 m of interconnecting piping.
9
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18
3
8 A U Z A 2
5
A 0 G 6 A 0 A 0
A
0
Model Type
Packaging
38AU= Carrier Condensing Unit
Puron® R---410A Refrigerant
0 = Standard
1 = LTL
Type of Coil
Z = Single Circuit, A/C Scroll Compressor
D = Dual Circuit, A/C Scroll Compressor
Electrical Options
A = None
C = Non-Fused Disconnect
Service Options
0 = None
Refrigerant Options
A = None
B = Low Ambient
1 = Un-powered Convenience Outlet
2 = Powered Convenience Outlet
Nominal Tonnage
16 = 15 Tons
Not Used
25 = 20 Tons
A = Place Holder
Not Used
Base Unit Controls
A = Not Used
0 = Electro-Mechanical Controls
Not Used
0 = Not Used
Design Rev
A = Initial Release
Voltage
1 = 575/3/60
5 = 208/230/3/60
6 = 460/3/60
Coil Options
NOVATION™ (Size 16 only)
G= Al/Al
RTPF (Sizes 16 & 25)
A= Cu/Al
K = E-Coat Al/Al
T = Al/Al with Hail Guard
B = Precoat (Cu/Al)
C = E-Coat (Cu/Al)
W= E-Coat Al/Al with Hail Guard M= Cu/Al with Hail Guard
N = Precoat (Cu/Al) with Hail Guard
P = E-Coat (Cu/Al) with Hail Guard
C10944
Fig. 3 - Model Number Nomenclature
POSITION NUMBER
TYPICAL
1
0
2
5
3
1
4
0
5
U
6
1
7
2
8
3
9
4
10
5
POSITION
1 – 2
3 – 4
DESIGNATES
Week of manufacture (fiscal calendar)
Year of manufacture ("10" = 2010)
5
Manufacturing location (U = Monterrey, Mexico)
Sequence number
6 – 10
C101041
Fig. 4 - Serial Number Nomenclature
10
Evaluate the path and required line length for
interconnecting refrigeration piping, including suction
riser requirements (outdoor unit above indoor unit), liquid
line lift (outdoor unit below indoor unit) and hot gas
bypass line. Relocate sections to minimize the length of
interconnecting tubing.
Matching 38AU Model To Evaporator Coil
The Model 38AUZ is a single-circuit unit design,
requiring one set of refrigeration piping. This model can
be connected to an evaporator coil with one circuit or with
two circuits (by manifolding the evaporator connections
into a single piping system).
DO NOT BURY REFRIGERATION LINES.
The Model 38AUD is a dual-circuit unit design that
requires two sets of refrigeration piping between the
outdoor unit and the evaporator coil (or coils). This model
can only be connected to an evaporator coil that has two
refrigeration circuits (or to two separate evaporator coils).
The Model 38AUD CANNOT be connected to a
single-circuit evaporator coil. The Model 38AUD
CANNOT be field-converted to a single-circuit design.
Although unit is weatherproof, avoid locations that permit
water from higher level runoff and overhangs to fall onto
the unit.
RIGHT:
REAR:
Min 18” (457 mm)
Min 18” (457 mm)
requried for service
requried for service
Table 3 – Evaporator Coil Connections
Evaporator Coil has Connect to Model Notes
FRONT:
LEFT:
42” (1067 mm)
Min 18” (457 mm)
Single Circuit
38AUZ ONLY
38AUZ
requried for service
Manifold evaporator
circuits into single
piping system
Note: Observe requirements for 39” (914 mm) operating clearance
on either Left or Rear coil opening.
Two Circuits
Or
C10201
38AUD
Use two separate
piping systems
Fig. 5 - Service Clearance Dimensional Drawing
Step 2 — Complete Pre-Installation Checks
Before unpacking this new 38AU model, compare the
evaporator coil design to the 38AU model.
Check Unit Electrical Characteristics: Confirm before
installation of unit that voltage, amperage and circuit
protection requirements listed on unit data plate agree with
power supply provided.
.INSTALLATION
Jobsite Survey
Un-crate Unit: Remove unit packaging except for the top
skid assembly, which should be left in place until after the
unit is rigged into its final location.
Complete the following checks before installation.
1. Consult local building codes and the NEC (National
Electrical Code) ANSI/NFPA 70 for special installa-
tion requirements.
2. Determine unit location (from project plans) or select
unit location.
Inspect Shipment: File a claim with shipping company if
the shipment is damaged or incomplete.
Consider System Requirements:
3. Check for possible overhead obstructions which may
interfere with unit lifting or rigging.
S Consult local building codes and National Electrical
Code (NEC, U.S.A.) for special installation
requirements.
Step 1 — Plan for Unit Location
S Allow sufficient space for airflow clearance, wiring,
refrigerant piping, and servicing unit. See Fig.1 and
Fig. 2 for unit dimensions and weight distribution data.
Select a location for the unit and its support system (pad,
rails or other) that provides for the minimum clearances
required for safety. This includes the clearance to
combustible surfaces, unit performance and service access
below, around and above unit as specified in unit
drawings. See Fig. 5.
S Locate the unit so that the outdoor coil (condenser)
airflow is unrestricted on all sides and above.
S The unit may be mounted on a level pad directly on the
base channels or mounted on raised pads at support
points. See Tables 1A through 2B for unit operating
weights. See Fig. 1 and Fig. 2 for weight distribution
based on recommended support points.
NOTE: Consider also the effect of adjacent units on
airflow performance and control box safety clearance.
Do not install the outdoor unit in an area where fresh air
supply to the outdoor coil may be restricted or when
recirculation from the condenser fan discharge is possible.
Do not locate the unit in a well or next to high walls.
NOTE: If vibration isolators are required for a particular
installation, use the data in Fig. 1 and Fig. 2 to make the
proper selection.
11
Table 4 – Equivalent Lengths for Common Fittings (ft)
Step 3 — Prepare Unit Mounting Support
Slab Mount —
Elbows
Nominal
Tube OD
90° Std 90° Lrad 90° Street 45° Std 45° Street
Provide a level concrete slab that extends a minimum of 6
in. (150 mm) beyond unit cabinet. Install a gravel apron in
front of condenser coil air inlet to prevent grass and
foliage from obstructing airflow.
3
/
1.3
1.4
1.6
1.8
2
0.8
0.9
1
2.2
2.3
2.5
2.9
3.2
4.1
5.6
6.3
8.2
0.6
0.7
0.8
0.9
0.9
1.3
1.7
2.1
2.6
1
8
1
5
3
/
/
/
1.1
1.3
1.5
1.6
2.1
3
2
8
4
8
Step 4 — Rig and Mount the Unit
1.2
1.4
1.7
2.3
2.6
3.3
7/
!
1
CAUTION
1 /
2.6
3.3
4
8
8
8
8
3
1 /
UNIT DAMAGE HAZARD
5
1 /
3.4
4.5
Failure to follow this caution may result in equipment
damage.
1
2 /
5
All panels must be in place when rigging. Unit is not
designed for handling by fork truck.
Tees
Nominal
Tube OD
Straight-Thru
No Reduct Reduce 25% Reduce 50%
Branch
Flow
3
Rigging: These units are designed for overhead rigging.
Refer to the rigging label for preferred rigging method.
Spreader bars are not required if top crating is left on the
unit. All panels must be in place when rigging. As further
protection for coil faces, plywood sheets may be placed
against the sides of the unit, behind cables. Run cables to
a central suspension point so that the angle from the
horizontal is not less than 45 degrees. Raise and set the
unit down carefully.
/
/
/
/
2.6
2.7
3
0.8
0.9
1
1.1
1.2
1.4
1.7
1.9
2.3
3.1
3.7
4.7
1.3
1.4
1.6
1.8
2
8
2
8
4
8
1
5
3
3.5
4
1.2
1.4
1.7
2.3
2.6
3.3
7/
1
1 /
5
2.6
3.3
4
8
8
8
8
3
1 /
7
5
1 /
8
1
If it is necessary to roll the unit into position, mount the
unit on longitudinal rails, using a minimum of 3 rollers.
Apply force to the rails, not the unit. If the unit is to be
skidded into position, place it on a large pad and drag it
by the pad. Do not apply any force to the unit.
2 /
10
5
Check 38AU Model with Evaporator Coil Connections —
Confirm before installation of unit that the evaporator coil
connections are consistent with this 38AU model. See
Table 3 on page 11.
Raise from above to lift the unit from the rails or pad
when unit is in its final position.
Determine Refrigerant Line Sizes —
After the unit is in position, remove all shipping materials
and top crating.
Select the recommended line sizes for 38AUZ and
38AUD unit from the appropriate tables.
Step 5 — Complete Refrigerant Piping
Connections
Determine the linear length of interconnecting piping
required between the outdoor unit and indoor unit
(evaporator). Consider and identify also the arrangement
of the tubing path (quantity and type of elbows in both
lines), liquid line solenoid size, filter drier and any other
refrigeration specialties located in the liquid line. Refer to
the indoor unit installation instructions for additional
details on refrigeration specialties devices.
IMPORTANT: Do not bury refrigerant piping
underground.
IMPORTANT: A refrigerant receiver is not provided
with the unit. Do not install a receiver.
Provide Safety Relief —
Determine equivalent line length adjustments for path and
components and add to linear line lengths. See Table 4,
Equivalent Lengths for Common Fittings, for usual fitting
types. Also identify adjustments for refrigeration
specialties. Refer to Part 3 of the Carrier System Design
Manual for additional data and information on equivalent
lengths.
If local codes dictate an additional safety relief device,
purchase locally and install locally. Installation will
require the recovery of the factory shipping charge before
the factory tubing can be cut and the supplemental relief
device is installed.
Model 38AUD has two separate refrigeration systems. If
required, each circuit will require a field-supplied/installed
supplemental relief device.
NOTE: Equivalent line lengths will vary based on tube
diameter. Calculate equivalent line length for each pipe by
adding equivalent length adjustments to linear lengths for
each pipe.
12
Enter the appropriate table to select the recommended line
sizes.
line tube size if necessary. If maximum available tube size
cannot provide the required lift distance on this
installation, relocate the outdoor unit to reduce the
equivalent line length or the lift requirement.
Model:
38AUZ
38AUD
Line Sizes Table Quantity of Line Sets
5
6
1
2
Suction Riser —
A suction riser condition exists when the outdoor unit is
located above the indoor (evaporator) unit and suction
vapor must flow vertically up to return to the compressor.
Oil return is a concern when the suction tube size is too
large to produce the minimum refrigerant velocity to
ensure oil return at minimum load conditions.
Liquid Lift —
A liquid lift condition exists when the outdoor unit is
located below the indoor (evaporator) unit and liquid
flows vertically up in a portion of the liquid line. The
vertical column of liquid reduces the available state point
subcooling at the evaporator coil’s thermal expansion
valve. This effect reduces the length of liquid lift (feet of
elevation) that a liquid line size can accommodate.
Longer linear tube lengths will also reduce the amount of
liquid lift possible.
Check Table 7 for maximum suction tube size for 38AU
units at minimum load conditions. Consider suction speed
riser (reduced tube size for vertical segment only) or
double suction riser arrangement if the recommended
suction tube size does not provide necessary minimum
flowrates for this riser.
Check Tables 5 (38AUZ) and 6 (38AUD) for maximum
liquid lift capabilities for line sizes. Reselect the liquid
Table 5 – 38AUZ 16-25 Piping Recommendations (Single-Circuit Unit)
R-410A
Equivalent Length
75-113
Ft
0-38
0-12
38-75
12-23
113-150
34-46
150-188
46-57
m
23-34
Linear Length
Ft
0-25
25-50
50-75
75-100
100-125
m
0-8
5
8-15
5
15-23
5
23-30
5
30-38
5
Model
38AUZ*16
Liquid Line
Max Lift
Suction Line
Charge (lbs)
Novation
RTPF
/
/
/
/
/
8
8
8
8
8
25
50
75
100
3
125
3
1
3
3
5
1- /
1- /
1- /
1- /
1- /
1- /
8
8
8
8
8
8
24.3
27.5
30.6
33.7
37.8
42.7
5
45.9
5
49.0
5
52.1
5
56.2
5
38AUZ*25
Legend:
Liquid Line
Max Lift
Suction Line
Charge (lbs)
/
/
/
/
/
8
8
8
8
8
25
50
71
77
63
1
3
3
3
5
5
5
1- /
1- /
1- /
1- /
1- /
1- /
1- /
8
8
8
8
8
8
8
37.8
40.8
44.6
47.8
51.1
Equivalent
Length
Equivalent tubing length, including effects of refrigeration specialties devices
Linear Length
Liquid Line
Max Lift
Typical linear tubing length, (50% added to linear to define Equivalent Length for this table)
Tubing size, inches OD.
Maximum liquid lift (indoor unit ABOVE outdoor unit only), at maximum permitted liquid line pressure drop —
S Linear Length Less than 75 ft (23 m): Minimum 2.0° F subcooling entering TXV
S Linear Length Greater than 75 ft (23m): Minimum 0.5° F subcooling entering TXV
Suction Line
Charge
Tube size, inches OD
Charge Quantity, lbs. Calculated for both liquid line sizes (where applicable), but only with larger suction line size
(where applicable)
NOTE:
For applications with equivalent length greater than 188 ft (57 m) and/0r linear length greater than 125 ft (38 m),
contact your local Carrier representative.
13
Table 6 – 38AUD 16-25 Piping Recommendations (Two-Circuit Unit)
NOTE: 38AUD requires TWO sets of refrigeration piping
R-410A
Equivalent Length
Ft
0-38
0-12
38-75
12-23
75-113
23-34
113-150
34-46
150-188
46-57
m
Linear Length
Ft
0-25
25-50
50-75
75-100
100-125
m
0-8
1
8-15
1
15-23
1
23-30
1
30-38
1
Model
38AUD*16
Liquid Line
Max Lift
/
/
/
/
/
2
2
2
2
2
25
7
50
75
100
1
125
1
1
1
Suction Line
Charge ea. (lbs)
Novation
RTPF
/
1 /
1 /
1 /
1 /
8
8
8
8
8
11.7
13.8
15.7
17.6
19.6
21.7
1
23.8
1
25.7
1
27.6
1
29.6
1
5
5
5
38AUD*25
Legend:
Liquid Line
Max Lift
/
/
/
/
/
/
/
/
8
2
2
2
8
2
8
2
25
50
54
75
60
99
46
95
1
1
1
1
3
3
Suction Line
1 /
1 /
1 /
1 /
1 /
1 /
8
8
8
8
8
8
Charge (lbs)
1
2
19.3
18.3
21.0
20.3
23.0
22.0
26.0
25.0
25.9
24.9
29.7
28.7
28.0
27.0
32.7
31.7
Equivalent
Length
Equivalent tubing length, including effects of refrigeration specialties devices
Linear Length
Liquid Line
Max Lift
Typical linear tubing length (50% added to linear to define Equivalent Length for this table)
Tubing size, inches OD.
Maximum liquid lift (indoor unit ABOVE outdoor unit only), at maximum permitted liquid line pressure drop —
S Linear Length Less than 75 ft (23 m): Minimum 2.0° F subcooling entering TXV
S Linear Length Greater than 75 ft (23m): Minimum 0.5° F subcooling entering TXV
Suction Line
Charge
Tube size, inches OD
Charge Quantity, lbs. Calculated for both liquid line sizes (where applicable), but only with larger suction line size
(where applicable)
NOTE:
For applications with equivalent length greater than 188 ft (57 m) and/0r linear length greater than 125 ft (38 m),
contact your local Bryant representative.
1
Table 7 – 38AU Maximum Suction Pipe Size
installed in the compressor discharge line. Run a /2-in OD
line between outdoor unit and evaporator coil inlet. Install an
Auxiliary Side Connector at the evaporator between TXV
and distributor (follow instructions for the side connector
part). Insulate the hot gas line.
Model:
Unit Size
Maximum Tube Size
5
16
25
16
25
1 /
8
8
8
8
38AUZ
5
1 /
5
38AUD: Generally only one hot gas bypass system will be
applied on a two-circuit unit. Connect the hot gas bypass
system to Circuit 1 (first-on/last-off, connected to the
evaporator coil’s bottom circuit).
1 /
38AUD
5
1 /
Vertical Separation (outdoor unit above indoor unit) –
38AUD Piping Connections —
Vertical elevation difference of 200 ft (60 m) is permitted
when the outdoor unit (38AUZ or 38AUD) is located
above the indoor unit.
The 38AUD’s two circuits are designated Circuit 1 and
Circuit 2. Circuit 1 is controlled by the thermostat’s Y1 (or
TC1) contact and will be the first circuit on and last circuit
off. Circuit 2 is controlled by the thermostat’s Y2 (or TC2)
contact and this circuit is always the “lag” circuit.
Insulate Suction Lines —
Apply closed-cell tubular insulation to all suction lines
between evaporator coil connection and 38AU unit’s
suction service valve.
See Fig. 6 for location of Circuit 1 and Circuit 2 service
valves and field piping connections. Circuit 1 is on the
left-hand side of the service valve compartment; Circuit 2
is on the right.
Hot Gas Bypass —
Hot gas bypass, if used, should be introduced before the
evaporator. (A bypass route that also bypasses the evaporator
circuit may lead to oil trapping in the evaporator circuit
during low load conditions and then to oil slugging as
evaporator load increases.) Model 38AU units do not include
a hot gas stub connection; a tee must be field-supplied and
When a single piece evaporator coil with two separate
circuits is connected to a 38AUD, the lower coil circuit
should be connected to the 38AUD’s Circuit 1 so that the
evaporator’s lower coil segment is first-on/last-off (to avoid
re-evaporation of condensate on dry lower coil segments).
14
38AU units include one (38AUZ) or two (38AUD)
Puron-duty filter drier(s), shipped in cartons attached to
the unit basepan. Remove the filter drier(s) and prepare to
install in the liquid line(s) at the evaporator coil. Do not
remove connection fitting plugs until ready to connect and
braze the filter drier into the liquid line position.
CKT
2
CKT
1
CKT
2
CKT
1
Circuit 2
Connections
Circuit 1
Connections
1
C10355
2
Fig. 6 - 38AUD Service Valve Locations
Plan the Circuit 1 and Circuit 2 tubing segments carefully,
mark each segment and check constantly as piping
systems are assembled to avoid piping errors.
FIRST ON/LAST OFF = 2
VERTICAL INSTALLATION
38AUD
single-circuit/tandem system.
unit
cannot
be
field-piped
as
a
2
Connecting 40RU to 38AUD: The 40RU fan coil in sizes
16, 25 and 28 is a face-split coil design that also has its
circuits designated as 1 and 2. See Fig. 7. Note that the
lower coil segment changes as the arrangement of the
40RU changes. In a vertical arrangement, the 40RU’s
lower coil segment is segment 2; this segment should be
connected to the 38AUD’s Circuit 1. In a horizontal
arrangement, the 40RU’s lower segment is now segment
1; this segment should be connected to the 38AUD’s
Circuit 1.
1
FIRST ON/LAST OFF = 1
HORIZONTAL INSTALLATION
C10071
Fig. 7 - Typical Evaporator Coil Connections (40RU)
Note that refrigerant suction piping should be insulated.
Table 8 – Puron-duty Filter Drier(s)
40RU
Cooling
Stage
40RU Coil
Segment
Connect to
38AUD
Arrangement
Liquid
Desiccant
Volume
Part
Model-Size
Qty
Line OD
Number Ref
Y1
Y2
2
1
Circuit 1
Circuit 2
Vertical
5
38AUZ*16
38AUZ*25
38AUD*16
38AUD*25
1
1
2
2
/ -in
8
30 cu. in.
30 cu. in.
16 cu. in.
16 cu. in.
KH43LG087
KH43LG087
KH43LG085
KH43LG085
Y1
Y2
1
2
Circuit 1
Circuit 2
5
1
1
/ -in
Horizontal
8
/ -in
2
/ -in
2
Install Filter Drier(s) and Moisture Indicator(s) —
Installation of liquid line moisture indicating sightglass in
each circuit is recommended. Locate the sightglass(es)
between the outlet of the filter drier and the TXV inlet.
Every unit MUST have a filter drier in the liquid line.
38AUD models require two filter driers (one in each
liquid line). Locate the filter drier(s) at the indoor unit,
close to the evaporator coil’s thermal expansion valve
(TXV) inlets.
Refer to Table 9 for recommendations on refrigeration
specialties.
Table 9 – Refrigerant Specialties Part Numbers.
LIQUID LINE
SIZE (in.)
LIQUID LINE
SOLENOID VALVE (LLSV)
LLSV
COIL
SIGHT
GLASS
FILTER
DRIER
1
/
/
EF680035
EF680036
EF680037
EF680037
KM680004
KM680005
2
8
provided with unit
see Table 8
5
38AUD units require TWO sets of parts.
15
from the indoor unit to the outdoor unit before opening
the liquid and suction lines at the outdoor unit.
EQUALIZER LINE
TXV
INDOOR
SENSING
BULB
SIGHT GLASS
A LOCATION
COIL CKT
FILTER DRIER
LOCATION
A
Install Liquid Line Solenoid Valve —
TXV
AIRFLOW
15 DIAMS
MIN
10
It is recommended that a solenoid valve be placed in the
main liquid line (see Figs. 8 & 9) between the condensing
unit and the evaporator coil. Locate the solenoid valve at the
outlet end of the liquid line, near the evaporator coil
connections, with flow direction arrow pointed at the
evaporator coil. Refer to Table 9. (A liquid line solenoid
valve is required when the liquid line length exceeds 75 ft
[23 m].) This valve prevents refrigerant migration (which
causes oil dilution) to the compressor during the off cycle, at
low outdoor ambient temperatures. Wire the solenoid in
parallel with the compressor contactor coil (see Figs. 8 & 9).
This means of electrical control is referred to as solenoid
drop control.
DIAMS
8 DIAMS
MIN
LIQUID LINE
SOLENOID
VALVE
Single Circuit Coil Piping Configuration
For single compressor condensing units
EQUALIZER LINE
TXV
INDOOR
SENSING
BULB
COIL CKT 2
SIGHT GLASS
A LOCATION
FILTER DRIER
A LOCATION
TXV
AIRFLOW
15 DIAMS
MIN
CKT 2
10
DIAMS
8 DIAMS
MIN
SIGHT
GLASSES
B LOCATION
TXV
Solenoid drop control wiring: Control the power to the
liquid line solenoid through a Solenoid Valve Relay (SVR)
in all units. Use part number HN61PC005 (field-supplied,
installed). 38AUZ unit requires one SVR; 38AUD unit
requires two relays.
FILTER
DRIERS
B LOCATION
SENSING
BULB
LIQUID LINE
INDOOR
SOLENOID
VALVE
COIL CKT 1
TXV
AIRFLOW
15 DIAMS
MIN
CKT 1
10
DIAMS
8 DIAMS
MIN
38AUD unit also requires
a
separate control power
transformer for the liquid solenoid valve loads. Select
transformer part number according to unit power supply.
Dual Circuit Coil Piping Configuration
For single compressor condensing units
C10202
Unit Power
208/230
460
Transformer Part #
HT01BD202
Fig. 8 - Location of Sight Glass(es) and Filter Driers
Typical 38AUZ Systems
HT01BD702
575
HT01BD902
EQUALIZER LINE
TXV
SENSING
BULB
Mount the SVR (and transformer TRAN3 when used) in
unit control box. Connect per wiring schematic label on
unit or per Fig. 29 (38AUZ) or Fig. 30 (38AUD).
AIRFLOW
TXV
15 DIAMS
MIN
CKT 2
10
DIAMS
8 DIAMS
MIN
Capacity Control Liquid Line Solenoid Valve:
Evaporator capacity staging control via direct thermostat
control of a liquid solenoid valve on the evaporator’s
second stage circuit is not possible with 38AU models. If
this installation is a retrofit for a unit that included
automatic pressure-operated unloading, check the existing
thermostat and liquid solenoid valve wiring for possible
direct thermostat control of a solenoid valve; re-wire per
Figs. 17 or 18 and 29 or 30.
SIGHT
GLASSES
LIQUID LINE
TXV
SOLENOID VALVE
CIRCUIT 2
SENSING
FILTER
BULB
DRIERS
TXV
AIRFLOW
15 DIAMS
MIN
CKT 1
10
DIAMS
8 DIAMS
MIN
LIQUID LINE
SOLENOID VALVE
CIRCUIT 1
SUCTION
CIRCUIT 1
SUCTION
CIRCUIT 2
Selecting an Accumulator –
Dual Circuit Coil Piping Configuration
For two circuit condensing units
Because all 38AU models use scroll compressors, an
accumulator is not required. If an accumulator is to be
added, check the accumulator manufacturer’s literature
carefully for indication of its suitability for use with
R-410A; look for minimum working pressure of 200 psig
(1380 kPa). Select the accumulator first on the basis of its
cataloged minimum capacity (tons) to ensure oil return from
the accumulator, then on tube size or holding capacity.
C10072
Fig. 9 - Location of Sight Glasses and Filter Driers
Typical 38AUD Systems
In some applications, depending on space and convenience
requirements, it may be desirable to install 2 filter driers and
sight glasses in a single circuit application. One filter drier
and sight glass may be installed at A locations (see Fig. 8) or
2 filter driers and sight glasses may be installed at B
locations (see Figs. 8 and 9).
Make Piping Connections —
Piping connections at the 38AU unit are ball valves with
stub tube extensions. Do not open the unit service valves
until all interconnecting tube brazing has been completed.
Select the filter drier for maximum unit capacity and
minimum pressure drop. Complete the refrigerant piping
16
The stub tube connections include 1/4-in SAE service
fittings with Schrader valve cores (see Fig. 10). Before
making any brazed connections to the unit service valves,
remove both Schrader valve caps and cores and save for
re-installation. Connect a source for nitrogen to one of
these service fittings during tube brazing to prevent the
formation of copper oxides inside the tubes at brazed
joints.
charging. For a cylinder without a dip tube, invert the
cylinder (access valve on the bottom) when removing
liquid refrigerant.
Because Puron (R-410A) refrigerant is a blend, it is
strongly recommended that refrigerant always be removed
from the cylinder as a liquid. Admit liquid refrigerant into
the system in the discharge line. If adding refrigerant into
the suction line, use a commercial metering/expansion
device at the gauge manifold; remove liquid from the
cylinder, pass it through the metering device at the gauge
set and then pass it into the suction line as a vapor. Do not
remove Puron (R–410A) refrigerant from the cylinder as a
vapor.
Field Service
Access Port
(Schrader core)
Factory
High-Flow
Preliminary Charge —
Access Port
Before starting the unit, charge R-410A liquid refrigerant
into the high side of each 38AU circuit through the liquid
service valve(s). The amount of refrigerant added must be
at least 80% of the operating charge listed in Tables 5 or 6
for LINEAR line length LESS the factory charge quantity
(if factory shipping charge has not been removed). See
example below.
Service Valve
with Stem Cap
Sweat
Connection
C10203
Fig. 10 - Typical Piping Connection Assembly
When connecting the field tubing to the 38AU service
valves, wrap the valves in wet rags to prevent overheating
Allow high and low side pressures to equalize. If pressures
do not equalize readily, charge R-410A vapor (using spe-
cial service manifold with expansion device) into the suc-
tion line service port for the low side of system to assure
charge in the evaporator. Refer to GTAC II, Module 5,
Charging, Recover, Recycling, and Reclamation for liquid
charging procedures.
Pressure-test all joints from outdoor unit connections over
to the evaporator coil, using nitrogen as pressure and with
soap-and-bubbles.
When pressure-testing is completed, remove the nitrogen
source at the outdoor unit service valves and re-install the
two Schrader valve cores. Torque the cores to 2-3 in-lbs
(23-34 N-cm).
Example:
38AUD*25 (RTPF)
60-ft (18.3 m) linear line length
Equivalent line length 90-ft (27.4 m)
Liquid Lift: 20-ft (6.1 m)
Select line sizes from Table 6 (38AUD):
Liquid 1/2 in
Evacuation/Dehydration —
Evacuate and dehydrate the connected refrigeration
system(s) (excluding the 38AU unit) to 500 microns using
a two-stage vacuum pump attached to the service ports
outside the 38AU service valves, following description in
GTAC II, Module 4, System Dehydration.
Suction 1-1/8 in.
Charge
!
WARNING
Circuit 1: 23.0 lbs (at 75-ft linear length)
Circuit 2: 22.0 lbs
UNIT OPERATION AND SAFETY HAZARD
Failure to follow this warning could cause personal
injury, death and/or equipment damage.
PuronR (R-410A) refrigerant systems operate at
higher pressure than standard R-22 systems. Do not
use R-22 service equipment or components on Puron
refrigerant equipment.
80% of Operating Charge:
Circuit 1: 0.80 x 23.0 = 18.4 lbs
Circuit 2: 0.80 x 22.0 = 17.6 lbs
Factory Shipping Charge: 15 lbs
Field-Charge
Circuit 1: 18.4 - 15 = 3.4 lbs
Circuit 2: 17.6 - 15 = 2.6 lbs
This unit is designed for use with Puron (R-410A)
refrigerant. Do not use any other refrigerant in this
system.
For linear line lengths longer than 125 ft (38 m), contact
your local Carrier representative for system charge value.
Puron (R-410A) refrigerant is provided in pink (rose)
colored cylinders. These cylinders are available with and
without dip tubes; cylinders with dip tubes will have a
label indicating this feature. For a cylinder with a dip
tube, place the cylinder in the upright position (access
valve at the top) when removing liquid refrigerant for
Step 6 — Install Accessories
Accessories requiring modifications to unit wiring should
be completed now. These accessories may include Winter
Start controls and Low Ambient controls. Refer to the
instructions shipped with the accessory.
17
Step 7 — Complete Electrical Connections
!
WARNING
!
WARNING
FIRE HAZARD
Failure to follow this warning could cause in personal
injury, death and/or equipment damage.
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Do not connect aluminum wire between disconnect
switch and condensing unit. Use only copper wire.
(See Fig. 11.)
Do not use gas piping as an electrical ground. Unit
cabinet must have an uninterrupted, unbroken electrical
ground to minimize the possibility of personal injury if
an electrical fault should occur. This ground may consist
of electrical wire connected to unit ground lug in control
compartment, or conduit approved for electrical ground
when installed in accordance with NEC (National
Electrical Code); ANSI/NFPA 70, latest edition (in
Canada, Canadian Electrical Code CSA [Canadian
Standards Association] C22.1), and local electrical
codes.
ELECTRIC
DISCONNECT
SWITCH
COPPER
WIRE ONLY
ALUMINUM
WIRE
NOTE: Check all factory and field electrical connections
for tightness. Field-supplied wiring shall conform with the
limitations of 63°F (33°C) rise.
A93033
Fig. 11 - Disconnect Switch and Unit
Field Power Supply —
Units Without Factory-Installed Disconnect —
If equipped with optional Powered Convenience Outlet:
The power source leads to the convenience outlet’s
transformer primary are not factory connected. Installer
must connect these leads according to required operation
of the convenience outlet. If an always-energized
convenience outlet operation is desired, connect the
source leads to the line side of the unit-mounted
disconnect. (Check with local codes to ensure this method
is acceptable in your area.) If a de-energize via unit
disconnect switch operation of the convenience outlet is
desired, connect the source leads to the load side of the
unit disconnect. On a unit without a unit-mounted
disconnect, connect the source leads to compressor
contactor C and indoor fan contactor IFC pressure lugs
with unit field power leads..
When installing units, provide a disconnect switch per
NEC (National Electrical Code) of adequate size.
Disconnect sizing data is provided on the unit informative
plate. Locate on unit cabinet or within sight of the unit per
national or local codes. Do not cover unit informative
plate if mounting the disconnect on the unit cabinet.
Units with Factory-Installed Disconnect —
The factory-installed option disconnect switch is located
in a weatherproof enclosure located under the main
control box. The manual switch handle is accessible
through an opening in the access panel.
All Units —
Field power wires are connected to the unit at line-side
pressure lugs on compressor contactor C and TB1 (see
wiring diagram label for control box component
arrangement) or at factory-installed option non-fused
disconnect switch. Max wire size is #4 AWG (copper
only).
All field wiring must comply with NEC and all local
codes. Size wire based on MCA (Minimum Circuit Amps)
on the unit informative plate. See Fig. 12 for power wiring
connections to the unit contactor and terminal block and
equipment ground.
Provide a ground-fault and short-circuit over-current
protection device (fuse or breaker) per NEC Article 440
(or local codes). Refer to unit informative data plate for
MOCP (Maximum Over-current Protection) device size.
NOTE: TEST LEADS - Unit may be equipped with short
leads (pigtails) on the field line connection points on
contactor C or optional disconnect switch. These leads are
for factory run-test purposes only; remove and discard
before connecting field power wires to unit connection
points. Make field power connections directly to line
connection pressure lugs only.
All units except 208/230-v units are factory wired for the
voltage shown on the nameplate. If the 208/230-v unit is
to be connected to a 208-v power supply, the control
transformer must be rewired by moving the black wire
with the 1/4-in. female spade connector from the 230-v
connection and moving it to the 208-v 1/4-in. male
terminal on the primary side of the transformer. Refer to
unit label diagram for line-side information.
18
and mounted on a bracket behind the convenience outlet;
access is through the unit’s control box access panel. See
Fig. 13.
Units Without Disconnect Option
C
TB1
11
13
Convenience
Outlet
GFCI
Disconnect
per
NEC
Pwd-CO
Fuse
Switch
L1
L2
L3
208/230-3-60
460-3-60
575-3-60
Pwd-CO
Transformer
Units With Disconnect Option
L1
2
1
Control Box
Access Panel
Optional
Disconnect
Switch
Factory
Wiring
L2
L3
4
6
3
5
C10205
Fig. 13 - Convenience Outlet Location
The primary leads to the convenience outlet transformer are
not factory-connected. Selection of primary power source is
a customer-option. If local codes permit, the transformer
primary leads can be connected at the line-side terminals on
the unit-mounted non-fused disconnect switch; this will
provide service power to the unit when the unit disconnect
switch is open. Other connection methods will result in the
convenience outlet circuit being de-energized when the unit
disconnect is open. See Fig. 14.
Disconnect factory test leads; discard.
C10204
Fig. 12 - Power Wiring Connections
Affix the crankcase heater warning sticker to the unit
disconnect switch.
Convenience Outlets —
!
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal
injury or death.
Units with convenience outlet circuits may use
multiple disconnects. Check convenience outlet for
power status before opening unit for service. Locate
its disconnect switch, if appropriate, and open it.
Tag-out this switch, if necessary.
Two types of convenience outlets are offered on 38AU
models: Non-powered and unit-powered. Both types
provide a 125-volt GFCI (ground-fault circuit-interrupter)
duplex receptacle rated at 15-A behind a hinged
waterproof access cover, located on the end panel of the
unit. See Fig. 13.
C10206
UNIT
CONNECT
AS
PRIMARY
TRANSFORMER
TERMINALS
VOLTAGE
CONNECTIONS
208,
230
L1: RED + YEL
L2: BLU + GRA
H1 + H3
H2 + H4
240
480
Non-powered type: This type requires the field
installation of a general-purpose 125-volt 15-A circuit
powered from a source elsewhere in the building. Observe
national and local codes when selecting wire size, fuse or
breaker requirements and disconnect switch size and
location. Route 125-v power supply conductors into the
bottom of the utility box containing the duplex receptacle.
L1: RED
Splice BLU +
YEL
H1
H2 + H3
H4
460
L2: GRA
L1: RED
L2: GRA
H1
H2
575
600
Fig. 14 - Powered Convenience Outlet Wiring
Unit-powered type:
A
unit-mounted transformer is
factory-installed to stepdown the main power supply voltage
to the unit to 115-v at the duplex receptacle. This option also
includes a manual switch with fuse, located in a utility box
The unit-powered convenience outlet has a 1000 VA rated
transformer. Maximum continuous current must not
exceed 8 Amps.
19
NOTICE
Convenience Outlet Utilization
Maximum Continuous use : 8 Amps 24/7
50HJ542739
B
C10207
Fig. 15 - Convenience Outlet Utilization Notice Label
Test the GFCI receptacle by pressing the TEST button on
the face of the receptacle to trip and open the receptacle.
Check for proper grounding wires and power line phasing
if the GFCI receptacle does not trip as required. Press the
RESET button to clear the tripped condition.
C09022
Fig. 16 - Weatherproof Cover Installation
All Units —
Fuse on power type: The factory fuse is a Bussman
“Fusetron” T-15, non-renewable screw-in (Edison base)
type plug fuse.
Voltage to compressor terminals during operation must be
within voltage range indicated on unit nameplate. See
Tables 10 and 11. On 3-phase units, voltages between
phases must be balanced within 2% and the current within
10%. Use the formula shown in the legend for Tables 10
and 11, Note 5 (see page 22) to determine the percent of
voltage imbalance. Operation on improper line voltage or
excessive phase imbalance constitutes abuse and may
cause damage to electrical components. Such operation
would invalidate any applicable Carrier warranty.
!
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal
injury or death.
Using unit-mounted convenience outlets: Units with
unit-mounded convenience outlet circuits will often
require that two disconnects be opened to de-energize
all power to the unit. Treat all units as electrically
energized until the convenience outlet power is also
checked and de-energization is confirmed. Observe
National Electrical Code Article 210, Branch Circuits,
for use of convenience outlets.
Field Control Wiring —
38AU unit control voltage is 24 v. See Fig. 29 (38AUZ)
and Fig. 30 (38AUD) for typical field control connections
and the unit’s label diagram for field-supplied wiring
details. Route control wires to the 38AU unit through the
opening in unit’s end panel to the connections terminal
board in the unit’s control box.
Installing Weatherproof Cover: A weatherproof while in
use cover for the factory installed convenience outlets is
now required by UL standards. This cover cannot be
factory mounted due its depth; it must be installed at unit
installation. For shipment, the convenience outlet is
covered with a blank cover plate.
Remainder of the system controls connection will vary
according to the specific construction details of the indoor
section (air handler or packaged fan coil). Fig. 17
(38AUZ) and Fig. 18 (38AUD) depict typical connections
to a Carrier 40RU fan coil unit. Plan for field connections
carefully and install control wiring correctly per the
project plan. Additional components and supplemental
transformer accessory may be required.
The weatherproof cover kit is shipped in the unit’s control
box. The kit includes the hinged cover, a backing plate
and gasket.
DISCONNECT ALL POWER TO UNIT AND
CONVENIENCE OUTLET.
The 38AU unit requires an external temperature control
device. This device can be a thermostat (field-supplied) or
a PremierLink controller (available as a field-installed
accessory, for use on a Carrier Comfort Network or as a
stand alone control).
Remove the blank cover plate at the convenience outlet;
discard the blank cover.
Loosen the two screws at the GFCI duplex outlet, until
approximately /2 -in (13 mm) under screw heads are
1
exposed. Press the gasket over the screw heads. Slip the
backing plate over the screw heads at the keyhole slots
and align with the gasket; tighten the two screws until
snug (do not overtighten).
Mount the weatherproof cover to the backing plate as
shown in Fig. 16. Remove two slot fillers in the bottom of
the cover to permit service tool cords to exit the cover.
Check for full closing and latching.
20
Thermostat —
Install a Carrier-approved accessory thermostat according
to installation instructions included with the accessory.
Locate the thermostat accessory on a solid wall in the
conditioned space to sense average temperature in
accordance with the thermostat installation instructions.
(Note 1)
The 38AUZ is a single-circuit, two-stage cooling unit.
Select a two—stage cooling thermostat, with or without
supplemental heating as needed.
(Note 3)
(Note 3)
The 38AUD is a dual-circuit, two-stage cooling unit.
Select a two—stage cooling thermostat, with or without
supplemental heating as needed.
(Note 2)
Select a thermostat cable or equivalent single leads of
different colors with minimum of five leads for 38AUZ or
six leads for
38AUD unit. Check the thermostat
installation instructions for additional features which
might require additional conductors in the cable.
For wire runs up to 50 ft. (15 m), use no. 18 AWG
(American Wire Gage) insulated wire (35 C minimum).
For 50 to 75 ft. (15 to 23 m), use no. 16 AWG insulated
wire (35 C minimum). For over 75 ft. (23 m), use no. 14
AWG insulated wire (35 C minimum). All wire sizes
larger than no. 18 AWG cannot be directly connected to
the thermostat and will require a junction box and splice
at the thermostat.
Note 1: Typical multi-function marking. Follow manufacturer’s configuration
instructions to select Y2.
Note 2: Connect only if thermostat requires 24-vac power source.
Note 3: Connect W1 and W2 if supplemental heaters are installed
Field Wiring
C10078
Fig. 18 - Typical Remote Thermostat Connections
— 38AUD
PremierLink (accessory installation) – Refer to Form
33CS-58SI for details on connecting the PremierLink
controller and its various sensors.
Control Circuit Wiring —
Control voltage is 24 v. See Fig. 12 and the unit’s label
diagram for field-supplied wiring details. Route control
wires through the opening in unit’s end panel to the
connection in the unit’s control box.
Control Transformer Wiring —
On multi voltage units, check the transformer primary
wiring connections. See Fig. 19 or refer to the unit’s label
diagram.
(Note 1)
(Note 3)
If the unit will be operating at 208-3-60 power, remove
the black wire (BLK) from the transformer primary
connection labelled “230” and move it to the connection
labelled “208”. See Fig. 19.
(Note 3)
(Note 2)
Note 1: Typical multi-function marking. Follow manufacturer’s configuration
instructions to select Y2.
Note 2: Connect only if thermostat requires 24-vac power source.
Note 3: Connect W1 and W2 if supplemental heaters are installed
Field Wiring
C10208
Fig. 17 - Typical Remote Thermostat Connections
— 38AUZ
C10079
Fig. 19 - Control Transformer Wiring
21
Table 10 – Unit Wire/Fuse or HACR Breaker Sizing Data
COMPRESSOR
No. 1 No. 2
NO C.O. or UNPWRD C.O.
NOMINAL
POWER
SUPPLY
VOLTAGE
RANGE
UNIT
SIZE
38AU
OFM
POWER SUPPLY
FUSE or
DISCONNECT SIZE
FLA
(ea)
V --- P h --- H z
Min
Max
RLA
LRA
RLA
LRA
Qty
MCA
HACR
BRKR
FLA
LRA
208/230---3---60
460 --- 3 --- 60
187
414
518
187
414
518
253
506
633
253
506
633
25.0
12.2
9.0
164
100
78
25.0
12.2
9.0
164
100
78
3
3
3
4
4
4
1.5
0.8
0.7
1.5
0.8
0.7
60.8/60.8
29.9
80/80
40
63/63
31
337/337
206
D*16
Z*16
575 --- 3 --- 60
22.4
30
23
162
208/230---3---60
460 --- 3 --- 60
30.1
16.7
12.2
225
114
80
30.1
16.7
12.2
225
114
80
73.7/73.7 100/100
76/76
42
462/462
236
D*25
Z*25
40.8
30.3
50
40
575 --- 3 --- 60
31
168
COMPRESSOR
No. 1 No. 2
w/ PWRD C.O.
NOMINAL
POWER
SUPPLY
VOLTAGE
RANGE
UNIT
SIZE
38AU
OFM
POWER SUPPLY
FUSE or
DISCONNECT SIZE
FLA
(ea)
V --- P h --- H z
Min
Max
RLA
LRA
RLA
LRA
Qty
MCA
HACR
BRKR
FLA
LRA
208/230---3---60
460 --- 3 --- 60
187
414
518
187
414
518
253
506
633
253
506
633
25.0
12.2
9.0
164
100
78
25.0
12.2
9.0
164
100
78
3
3
3
4
4
4
1.5
0.8
0.7
1.5
0.8
0.7
65.6/65.6
32.1
90/90
40
68/68
33
342/342
208
D*16
Z*16
575 --- 3 --- 60
24.1
30
25
164
208/230---3---60
460 --- 3 --- 60
30.1
16.7
12.2
225
114
80
30.1
16.7
12.2
225
114
80
78.5/78.5 100/100
82/82
45
467/467
238
D*25
Z*25
43
32
50
40
575 --- 3 --- 60
33
170
Legend and Notes for Table 10
LEGEND:
Example: Supply voltage is 230-3-60
BRKR
CO
--- Circuit breaker
--- Convenient outlet
--- Fu ll L o a d A m p s
--- Locked Rotor Amps
--- Minimum Circuit Amps
Protection
max voltage deviation from average voltage
average voltage
F L A
% Voltage Imbalance = 100 x
LRA
MCA
AB = 224 v
BC = 231 v
AC = 226 v
NEC
PWRD CO
RLA
UNPWR CO
NOTES:
--- National Electrical Code
--- Powered convenient outlet
--- Rated Load Amps
--- Unpowered convenient outlet
(224 + 231 + 226)
681
3
Average Voltage =
=
=
3
1. In compliance with NEC requirements for multimotor and
combination load equipment (refer to NEC Articles 430 and
440), the overcurrent protective device for the unit shall be
fuse or HACR breaker. Canadian units may be fuse or circuit
breaker.
2. The MCA values are calculated in accordance with The NEC.
Article 440.
3. Motor RLA and LRA values are established in accordance
with Underwriters’ Laboratories (UL). Standard 1995.
4 . T h e 5 7 5 --- v u n it s a r e UL , C a n a d a --- li st e d o n ly.
227
Determine maximum deviation from average voltage.
(AB) 227 – 224 = 3 v
(BC) 231 – 227 = 4 v
(AC) 227 – 226 = 1 v
Maximum deviation is 4 v.
Determine percent of voltage imbalance.
5. Unbalanced 3-Phase Supply Voltage
4
Never operate a motor where a phase imbalance in supply
voltage is greater than 2%. Use the following formula to de-
termine the percentage of voltage imbalance.
% Voltage Imbalance
= 100 x
= 1.76%
227
This amount of phase imbalance is satisfactory as it is below the
maximum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is more than
2%, contact your local electric utility company immediately.
22
PRE-START-UP
!
CAUTION
IMPORTANT: Before beginning Pre-Start-Up or
Start-Up, review Start-Up Checklist at the back of this
book. The Checklist assures proper start-up of a unit
and provides a record of unit condition, application
requirements, system information, and operation at
initial start-up.
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage.
Prior to starting compressor, a preliminary charge of
refrigerant must be added to avoid possible
compressor damage.
!
CAUTION
START-UP
UNIT DAMAGE HAZARD
38AU Units: The compressor crankcase heater must be on
for 24 hours before start-up. After the heater has been on
for 24 hours, the unit can be started. If no time elapsed
since the preliminary charge step was completed, it is
unnecessary to wait the 24-hour period.
Failure to follow this caution may result in equipment
damage.
Do not attempt to start the condensing unit, even
momentarily, until the following steps have been
completed. Compressor damage may result.
Preliminary Checks
1. Check that electric power supply agrees with unit
nameplate data.
System Check
1. The electrical power source must agree with the unit’s
nameplate rating.
2. Verify that the compressor crankcase heater is se-
curely in place.
2. Check all air handler(s) and other equipment auxiliary
components. Consult the manufacturer’s instructions re-
garding any other equipment connected to the condens-
ing unit. If the unit has field-installed accessories, be
sure all are properly installed and correctly wired. If
used, the airflow switch must be properly installed.
3. Check that the compressor crankcase heater has been
on at least 24 hours.
4. Recheck for leaks using the procedure outlined in the
Pre-Start-Up section, Leak Test and Dehydration. If
any leaks are detected, repair as required. Evacuate
and dehydrate as described in the Leak Test and De-
hydration section.
3. Check tightness of all electrical connections.
4. Be sure liquid line and low side of the system are
properly leak checked and dehydrated.
5. Be sure the unit is properly charged. See “Preliminary
Charge”, below.
5. Ensure that the preliminary charge has been added as
described in the Pre-Start-Up section, Preliminary
Charge.
6. All internal wiring connections must be tight, and all
barriers and covers must be in place.
6. Open the liquid line and suction line service valves.
NOTE: The 38AU units are factory charged with the
required amount of oil. If recharging in required, use
Emkarate RL 32-3MAF for the 38AU units.
7. The crankcase heater must be firmly attached to the
compressor crankcase. Be sure the crankcase is warm
(heater must be on for 24 hours before starting com-
pressor).
Compressor Rotation —
Turn On Crankcase Heater —
On 3-phase units with scroll compressors, it is important to
be certain that the compressor is rotating in the proper
direction. 38AU units are equipped with a Comfort Alert
Diagnostic Module (CADM). Alert Code 7 indicates reverse
power phasing.
Turn on the crankcase heater for 24 hours before starting
the unit to be sure all the refrigerant is out of the oil. To
energize the crankcase heater, proceed as follows:
1. Set the space thermostat set point above the space
temperature so there is no demand for cooling.
2. Close the field disconnect.
To correct phase order:
1. Turn off power to the unit, tag disconnect.
2. Reverse any two of the unit power leads.
Preliminary Charge —
3. Reapply power to the compressor, verify correct pres-
sures.
Before starting the unit, charge liquid refrigerant into the
high side of the system through the liquid service valve. The
amount of refrigerant added must be at least 80% of the
operating charge listed in the Physical Data table (Tables 1A
through 2B, pages 6 through 9). Allow high and low side
pressures to equalize before starting compressor. If pressures
do not equalize readily, charge vapor on low side of system
to assure charge in the evaporator. Refer to GTAC II,
Module 5, Charging, Recover, Recycling, and Reclamation
for liquid charging procedures.
To verify the compressor is rotating in the proper
direction:
1. Connect service gages to the suction and liquid pres-
sure fittings.
2. Energize the compressor.
3. The suction pressure should drop and the liquid pres-
sure should rise, as is normal on any start-up.
23
Compressor Overload —
Start Unit
This overload interrupts power to the compressor when
either the current or internal motor winding temperature
becomes excessive, and automatically resets when the
internal temperature drops to a safe level. This overload
may require up to 60 minutes (or longer) to reset. If the
internal overload is suspected of being open, disconnect
the electrical power to the unit and check the circuit
through the overload with an ohmmeter or continuity
tester.
Set the space thermostat to a set point above space
temperature so that there is no demand for cooling. Close
the 38AU disconnect switch. Only the crankcase heater
will be energized.
Reset the space thermostat below ambient so that a call
for cooling is ensured.
!
CAUTION
Advanced Scroll Temperature Protection (ASTP) —
UNIT DAMAGE HAZARD
A label located above the terminal box identifies Copeland
Scroll compressor models that contain this technology. See
Fig. 20. Advanced Scroll Temperature Protection (ASTP) is
a form of internal discharge temperature protection, that
unloads the scroll compressor when the internal temperature
reaches approximately 149_C (300_F). At this temperature,
an internal bi-metal disk valve opens and causes the scroll
elements to separate, which stops compression. Suction and
discharge pressures balance while the motor continues to
run. The longer the compressor runs unloaded, the longer it
must cool before the bi-metal disk resets. See Fig. 21.
Failure to follow this caution may result in equipment
damage.
Never charge liquid into the low-pressure side of
system. Do not overcharge. During charging or
removal of refrigerant, be sure indoor-fan system is
operating. Ensure both outdoor fan motors are
running; bypass any Motormaster function.
Adjust Refrigerant Charge —
Refer to Cooling Charging Charts, Fig. 23 through Fig. 28.
For applications with line lengths greater than 125 ft (38 m),
contact Carrier representative. Vary refrigerant until the
conditions of the chart are met. Note that the charging charts
are different from the type normally used. The charts are
based on charging the units to the correct subcooling for the
various operating conditions. Accurate pressure gage and
temperature sensing device are required. Connect the
pressure gage to the service port on the liquid line service
valve. Mount the temperature sensing device on the liquid
line close to the liquid line service valve, and insulate it so
that outdoor ambient temperature does not affect the reading.
Indoor airflow must be within the unit’s normal operating
range. Operate the unit for a minimum of 15 minutes.
Ensure that pressure and temperature readings have
stabilized. Plot the liquid pressure and temperature on chart
and add or reduce the charge to meet the curve. Adjust the
charge to conform with the charging chart, using the liquid
pressure and temperature to read the chart.
C10080
Fig. 20 - Advanced Scroll Temperature Protection Label
120
110
100
90
80
70
60
50
40
30
20
10
0
Using plotted operating point:
If plotted operating condition is -
BELOW the curve
Adjust charge by -
REDUCE charge
ADD charge
0
10
20
30
40
50
60
70
80
90
ABOVE the curve
Compressor Unloaded Run Time (Minutes)*
*Times are approximate.
NOTE: Various factors, including high humidity, high ambient
temperature, and the presence of a sound blanket will
increase cool-down times.
C10081
Fig. 21 - Recommended Minimum Cool-Down Time
After Compressor is Stopped
To manually reset ASTP, the compressor should be
stopped and allowed to cool. If the compressor is not
stopped, the motor will run until the motor protector trips,
which occurs up to 90 minutes later. Advanced Scroll
Temperature Protection will reset automatically before the
motor protector resets, which may take up to 2 hours.
24
38AUZ*25 Check Compressor Oil Level —
IMPORTANT: Oil level should only be checked
when the compressors are off.
After adjusting the refrigerant charge, allow the unit to
run fully loaded for 20 minutes. Stop the compressors and
check the oil level. Oil level should be /3 to /2 up on the
sight glass (see Fig. 22).
Add oil only if necessary to bring the oil into view in the
sight glass. If oil is added, run the circuit for an additional
10 minutes, then stop and check oil level. If the level
remains low, check the piping system for proper design
for oil return; also, check the system for leaks. If checking
the oil level with unit running in part load, let unit run one
hour, then run at full load for 10 minutes. If oil does not
return to acceptable sight glass levels, check for correct
suction piping and line sizing.
1
1
1/2 (MAX)
1/3 (MIN)
Final Checks —
Ensure that all safety controls are operating, control panel
covers are on, and the service panels are in place.
C01377
Fig. 22 - Recommended Oil Level — 38AUZ*25
C10945
Fig. 23 - 38AUZ*16 Charging Chart (Novation)
25
(CIRCUIT 1)
(CIRCUIT 2)
C10946
Fig. 24 - 38AUD*16 Charging Chart (Novation)
26
C10947
Fig. 25 - 38AUZ*16 Charging Chart (RTPF)
C10948
Fig. 26 - 38AUZ*25 Charging Chart (RTPF)
27
C10949
Fig. 27 - 38AUD*16 Charging Chart (RTPF)
28
(CIRCUIT 1)
(CIRCUIT 2)
C10950
Fig. 28 - 38AUD*25 Charging Chart (RTPF)
29
C10212A
Fig. 29 - Typical 38AUZ Wiring Diagram - (15 Ton 230V Tandem Unit Shown)
30
C10213A
Fig. 30 - Typical 38AUD Wiring Diagram - (15 Ton 230V Dual Unit Shown)
31
On a thermostat calling for Stage 2 Cooling, thermostat
output Y2 is energized; terminal Y2 at 38AUD unit
receives 24-v. 24-v received at CADM2 terminal Y. If
anti-recycle time delay period has not expired, CADM2
relay will remain open, de-energizing Solenoid Valve
Relay 2 (SVR2) and preventing compressor start. When
safety pressure switches are closed and CADM2 time
delay expires, CADM2 relay closes, SVR2 and
compressor contactor C2 are energized; liquid line
solenoid valve LLSV2 opens and Circuit 2 compressor
starts.
OPERATING SEQUENCE
Base Unit Controls
Indoor (Supply) Fan —
The indoor fan contactor (IFC) is remotely located at the fan
coil or fan section. If the thermostat fan operation is selected
as Continuous, the IFC is energized and the indoor (supply)
fan motor runs continuously. If the thermostat fan operation
is selected as Automatic, the IFC will be energized on a call
for Cooling; indoor (supply) fan motor runs. When
thermostat call for Cooling is satisfied, the IFC is
de-energized and indoor (supply) fan motor stops.
As space cooling load is satisfied, thermostat outputs Y2
and Y1 are de-energized, removing 24-v at 38AUD
terminals Y2 and Y1. Circuit 2 compressor stops on Y2
opening; SVR2 is de-energized and LLSV2 closes.
CADM2 begins its three-minute anti-recycle time delay.
On Y1 opening, Circuit 1 compressor stops, all outdoor
fan motors stop and SVR1 relay is de-energized. Liquid
line solenoid valve LLSV1 is de-energized and valve
closes. CADM1 begins its three-minute anti-recycle time
delay.
Cooling, Unit Without Economizer —
38AUZ (Single Circuit)
On a thermostat call for Cooling, IFC will be energized
and indoor (supply) fan motor runs. Thermostat output Y1
is energized; terminal Y1 at 38AUZ unit receives 24-v.
24-v received at CADM1 terminal Y. If anti-recycle time
delay period has not expired, CADM1 relay will remain
open, de-energizing Solenoid Valve Relay (SVR) and
preventing compressor start. When safety pressure
switches are closed and CADM1 time delay expires,
CADM1 relay closes, SVR and compressor contactor C1
are energized; liquid line solenoid valve LLSV opens, all
outdoor fan motors start and Compressor 1 starts.
All Units
If either the Low Pressure Switch or High Pressure Switch
opens while thermostat output Y1 or Y2 remain energized,
the compressor contactor is de-energized, the compressor
stops and liquid line solenoid is de-energized (valve
closes). CADM initiates a TRIP event (cooling demand
sensed at CADM terminal Y but no current is measured at
T1, T2, T3 motor sensors); CADM relay opens and RED
LED is illuminated. TRIP condition maintains lockout of
compressor operation until CADM is manually reset.
Reset CADM by cycling unit main power.
On a thermostat calling for Stage 2 Cooling, thermostat
output Y2 is energized; terminal Y2 at 38AUZ unit
receives 24-v. 24-v received at CADM2 terminal Y. If
anti-recycle time delay period has not expired, CADM2
relay will remain open, preventing Compressor 2 start.
When safety pressure switches are closed and CADM2
time delay expires, CADM2 relay closes, compressor
contactor C2 is energized; Compressor 2 starts.
Complete system shutdown may be caused by loss of
main power, open compressor internal overload, open
low-pressure or high-pressure switch, or a fault detected
by the CADM logic. Compressor operation without
cooling may indicate the compressor’s ASTP feature is
active; disconnect unit power and allow compressor to
cool. See Service section for further details.
As space cooling load is satisfied, thermostat outputs Y2
and Y1 are de-energized, removing 24-v at 38AUZ
terminals Y2 and Y1. Compressor 2 stops on Y2 opening.
CADM2 begins its three-minute anti-recycle time delay.
On Y1 opening, Compressor 1 stops, all outdoor fan
motors stop and SVR relay is de-energized. Liquid line
solenoid valve is de-energized and valve closes. CADM1
begins its three-minute anti-recycle time delay.
Cooling, Unit With Economizer —
Refer to fan coil unit installation instructions and
economizer accessory installation instructions for
operating sequences when system is equipped with
accessory economizer.
38AUD (Two Circuit)
On a thermostat call for Cooling, IFC will be energized
and indoor (supply) fan motor runs. Thermostat output Y1
is energized; terminal Y1 at 38AUD unit receives 24-v.
24-v received at CADM1 terminal Y. If anti-recycle time
delay period has not expired, CADM1 relay will remain
open, de-energizing Solenoid Valve Relay 1 (SVR1) and
preventing compressor start. When safety pressure
switches are closed and CADM1 time delay expires,
CADM1 relay closes, SVR1 and compressor contactor C1
are energized; liquid line solenoid valve LLSV1 opens, all
outdoor fan motors start and Circuit 1 compressor starts.
Heating —
Refer to fan coil unit installation instructions and accessory
heating device installation instructions for operating
sequences in heating mode.
32
ROUTINE SYSTEM MAINTENANCE
SERVICE
These items should be part of a routine maintenance
program, to be checked every month or two, until a specific
schedule for each can be identified for this installation:
Refrigeration System
!
CAUTION
Quarterly Inspection (and 30 days after initial start) —
EQUIPMENT DAMAGE HAZARD
Indoor section
Failure to follow this caution may result in damage to
equipment.
S Condenser coil cleanliness checked.
S Return air filter replacement
S Outdoor hood inlet filters cleaned
S Belt tension checked
This system uses PuronR refrigerant which has higher
pressures than R-22 and other refrigerants. No other
refrigerant may be used in this system. Gage set,
hoses, and recovery system must be designed to
handle Puron. If you are unsure consult the equipment
manufacturer.
S Belt condition checked
S Pulley alignment checked
S Fan shaft bearing locking collar tightness checked
S Condensate drain checked
Compressor Oil —
!
CAUTION
Seasonal Maintenance —
EQUIPMENT DAMAGE HAZARD
These items should be checked at the beginning of each
season (or more often if local conditions and usage patterns
dictate):
Failure to follow this caution may result in damage to
equipment.
The compressor in a Puron system uses a polyolester
(POE) oil. This oil is extremely hygroscopic, meaning
it absorbs water readily. POE oils can absorb 15 times
as much water as other oils designed for HCFC and
CFC refrigerants. Take all necessary precautions to
avoid exposure of the oil to the atmosphere.
Air Conditioning
S Condenser fan motor mounting bolts tightness
S Compressor mounting bolts
S Condenser fan blade positioning
S Control box cleanliness and wiring condition
S Wire terminal tightness
Servicing Systems on Roofs With Synthetic Materials —
S Refrigerant charge level
POE (polyolester) compressor lubricants are known to cause
long term damage to some synthetic roofing materials.
Exposure, even if immediately cleaned up, may cause
embrittlement (leading to cracking) to occur in one year or
more. When performing any service which may risk
exposure of compressor oil to the roof, take appropriate
precautions to protect roofing. Procedures which risk oil
leakage include but are not limited to compressor
replacement, repairing refrigerants leaks, replacing
refrigerant components such as filter drier, pressure switch,
metering device, coil, accumulator, or reversing valve.
S Evaporator coil cleaning
S Evaporator blower motor amperage
Heating
S Power wire connections
S Fuses ready
S Manual-reset limit switch is closed
Economizer or Outside Air Damper
S Inlet filters condition
Synthetic Roof Precautionary Procedure:
S Check damper travel (economizer)
S Check gear and dampers for debris and dirt
1. Cover extended roof working area with an imper-
meable polyethylene (plastic) drop cloth or tarp.
Cover an approximate 10 x 10 ft (3.3 x 3.3 m) area.
2. Cover area in front of the unit service panel with a
terry cloth shop towel to absorb lubricant spills and
prevent run-offs, and protect drop cloth from tears
caused by tools or components.
3. Place terry cloth shop towel inside unit immediately un-
der component(s) to be serviced and prevent lubricant
run-offs through the louvered openings in the base pan.
4. Perform required service.
5. Remove and dispose of any oil contaminated material
per local codes.
33
Liquid Line Filter Drier —
Factory High-Flow Access Ports —
The factory-provided filter drier is specifically designed to
operate with Puron®. Replace the filter drier with
factory-authorized components only with a filter drier
with desiccant made from 100% molecular sieve grade
XH-11. Filter drier must be replaced whenever the
refrigerant system is opened.
There are two additional access ports in the system - on
the suction tube between the compressor and the suction
service valve and on the liquid tube near the liquid service
valve (see Figs 35 and 39). These are brass fittings with
black plastic caps. The hose connection fittings are
standard 1/4-in SAE Male Flare couplings.
When removing a filter drier, use a tubing cutter to cut the
drier from the system. Do not unsweat a filter drier from
the system. Heat from unsweating will release moisture
and contaminants from drier into system.
The brass fittings are two-piece High Flow valves, with a
receptacle base brazed to the tubing and an integral
spring-closed check valve core screwed into the base. (See
Fig. 31) This check valve is permanently assembled into
this core body and cannot be serviced separately; replace
the entire core body if necessary. Service tools are
available from RCD that allow the replacement of the
check valve core without having to recover the entire
system refrigerant charge. Apply compressor refrigerant
oil to the check valve core’s bottom o-ring. Install the
fitting body with 96 ±-10 in-lbs (1085 ±23 N-cm) of
torque; do not overtighten.
Field Refrigerant Access Ports —
Field service access to refrigerant pressures is through the
access ports located at the service valves (see Figs 34 and
38). These ports are 1/4-in SAE Flare couplings with
Schrader check valves and service caps. Use these ports to
admit nitrogen to the field tubing during brazing, to
evacuate the tubing and evaporator coil, to admit initial
refrigerant charge into the low-side of the system and
when checking and adjusting the system refrigerant
charge. When service activities are completed, ensure the
service caps are in place and secure; check for leaks. If
the Schrader check valve must be removed and
re-installed, tighten to 2-3 in-lbs (23-34 N-cm).
SEAT
CORE
(Part No. EC39EZ067)
1/2-20 UNF RH
0.596
45°
30°
WASHER
O-RING
DEPRESSOR PERARI720
1/2" HEX
+.01/-.035
.47
5/8” HEX
FROM FACE OF BODY
This surface provides a metal to metal seal when
torqued into the seat. Appropriate handling is
required to not scratch or dent the surface.
7/16-20 UNF RH
C08453
Fig. 31 - CoreMax Access Port Assembly
34
POWER
(GRN)
Comfort Alert Diagnostic Module
The Comfort Alert Diagnostic Module (CADM) monitors
and analyzes data from the Copeland Scroll® three-phase
compressor and the thermostat demand. The CADM also
provides a 3-minute anti-recycle time delay to compressor
cycling. Each compressor has a separate CADM module.
The CADM detects causes for electrical and system
related failures without any sensors. Flashing LEDs
communicate the Alert codes to guide service technicians
in accurately and quickly troubleshooting the system and
determining root cause for the failure.
ALERT
(YEL)
Inputs to the CADM include 24-vac power, thermostat Y1
or Y2, compressor contactor coil (common side) and
compressor power leads (from the compressor contactor).
TRIP
(RED)
C10086
Fig. 32 - CADM Housing/LED Locations
Input
Terminal
Voltage
The TRIP LED indicates either a time-delay period is
currently active (RED LED is blinking) or the module has
locked out the compressor (RED LED is on steady). A
lockout condition will occur when the CADM detects a
thermostat demand at input Y but there is no power at the
compressor line terminals T1 or T2 or T3. This lockout
can occur due to a safety switch (LPS or HPS) opening
and de-energizing the compressor contactor, the
compressor-motor internal overload opens, or other
internal power interruption has occurred. Reset of the
TRIP LED requires that unit main power be recycled after
the loss of power to the compressor condition has been
detected and corrected.
Control
Power
R
24-V
Control
Common
C
Y
P
24-V
24-V
24-V
Cooling
Contactor
Coil
Line A
Line B
Line C
T1
T2
T3
Line
Line
Line
Control of the compressor contactor coil is through a
normally-closed (power on the module) contact between
terminals P and C.
Simultaneous Blinking of YELLOW and RED LEDs
indicates control power input to the CADM is low. Check
control circuit transformer and wiring.
Communications of status and alert conditions is through
three LEDs located on the top edge of the module housing
(see Fig. 32): POWER (green), ALERT (yellow), and
TRIP (red).
Troubleshooting the CADM Wiring – Flashing LEDs also
indicate wiring problems to the CADM. See Table 12 for
discussion of additional LED flash codes and
troubleshooting instructions.
The POWER LED indicates the presence of control power
to the CADM.
The ALERT LED indicates an abnormal condition exists
in the system through a flash code. The ALERT LED will
blink a number of times consecutively, pause and the
repeat the process. The number of blinks, defined in Table
11, correlates to
a
particular abnormal condition;
troubleshooting tips are provided for each Alert code.
Reset of the ALERT may be automatic or manual. If the
fault condition causing the Alert is self-corrected, the
Alert code will be removed and the CADM will
automatically reset and allow the system to restart
normally. Manual reset requires that main power to the
38AU unit be recycled after the cause for the Alert
condition has been detected and corrected.
35
Table 11 – LED Status Codes
Status LED
Status LED Description
Status LED Troubleshooting Information
Green “POWER” Module has power
Supply voltage is present at module terminals
1. Compressor protector is open
Red “TRIP”
Thermostat demand signal
Y is present, but the com-
pressor is not running.
LED On Solid
2. Condensing unit power disconnect is open
3. Compressor circuit breaker or fuse(s) is open
4. Broken supply wires or connector is not making contact
5. Compressor power wires not routed through Comfort Alert
6. Compressor contactor has failed open
Red “TRIP” LED The anti-short cycle timer (3 minutes) in module is preventing compressor restart.
Flashing
Module locks out compressor when compressor damaging ALERT code appears.
Lockout ALERT codes are noted in the Status LED Description.
During a compressor lock out, 24VAC power must be removed from module to manually reset.
1. Compressor contactor coil shorted
Yellow “ALERT”
LED On Solid
A short circuit or over cur-
rent condition exists on
PROT terminal.
2. Electrical load too high for PROT circuit (maximum 1 Amp)
3. 24 V AC wired directly to PROT terminal
1. High head pressure
Yellow “ALERT”
Flash Code 2
System Pressure Trip
Discharge pressure out of
limits or compressor over-
load (if no high pressure
switch in system)
2. Condenser coil poor air circulation (dirty, blocked, damaged)
3. Condenser fan is not running
4. If low pressure switch is open: Refer to Code 3 for troubleshooting
1. If low pressure switch is open:
LOCKOUT
Yellow “ALERT”
Flash Code 3
Short Cycling
Compressor is running only
briefly (four consecutive
cycles of less than three
minutes each)
a. Low refrigerant charge
b. Evaporator blower is not running
c. Evaporator coil is frozen
LOCKOUT
d. Faulty metering device
e. Condenser coil is dirty
f. Liquid line restriction (filter drier blocked if present)
2. If high pressure switch is open, go to Flash Code 2 information
3. Intermittent thermostat demand signal
4. System or control board defective
1. Low line voltage to compressor
Yellow “ALERT”
Flash Code 4
Locked Rotor
LOCKOUT
2. Excessive liquid refrigerant in compressor
3. Compressor bearings are seized
1. Condensing unit power disconnect is open
2. Compressor circuit breaker or fuses are open
3. Compressor contactor has failed open
4. High pressure switch is open and requires manual reset
5. Broken supply wires or connector is not making contact
Yellow “ALERT”
Flash Code 5
Open Circuit
6. Unusually long compressor protector reset time due to extreme
ambient temperature
7. Compressor windings are damaged
1. Compressor fuse is open on one phase
2. Broken wire or connector on one phase
3. Compressor motor winding is damaged
4. Utility supply has dropped one phase
Yellow “ALERT”
Flash Code 6
Missing Phase
LOCKOUT
Yellow “ALERT”
Flash Code 7
Reverse Phase
LOCKOUT
1. Compressor running backward due to supply phase reversal
1. Compressor contactor has failed closed
2. Thermostat demand signal not connected to module
1. Control circuit transformer is overloaded
2. Low line voltage to compressor
Yellow “ALERT”
Flash Code 8
Welded Contactor
Compressor always runs
Yellow “ALERT”
Flash Code 9
Low Voltage
Control circuit < 18VAC
36
Table 12 – CADM Troubleshooting
Miswired Module Indication
Recommended Troubleshooting Action
Green LED is not on,
module does not power up
Determine if both R and C module terminals are connected. Verify voltage in present at module’s R
and C terminals.
NOTE: The CADM requires a constant nominal 24VAC power supply. The wiring to the module’s R
and C terminals must be directly from the control transformer. The module cannot receive its power
from another device that will interrupt the 24VAC power supply. See the 38AU Wiring Diagram(s)
(Fig. 29 and Fig. 30).
Green LED Intermittent,
module powers up only
when compressor runs
Determine if R and Y terminals are wired in reverse. Verify module’s R and C terminals have a con-
stant source. See “NOTE” above for details on R and C wiring.
TRIP LED is on but system
and compressor check OK
Verify Y terminal is wired properly per the 38AU wiring diagram (see Fig. 29 and Fig. 30). Verify
voltage at contactor coil falls below 0.5VAC when off. Verify 24VAQC is present across Y and C
when thermostat demand signal is present. If not, R and C are reverse wired.
TRIP LED and ALERT LED
flashing together
Verify R and C terminals are supplied with 19-28VAC.
ALERT Flash Code 3
(Compressor Short Cycling)
displayed incorrectly
Verify Y terminal is connected to 24VAC at contactor coil. Verify voltage at contactor coil falls below
0.5VAC when off.
ALERT Flash Code 5 or 6
(Open Circuit, Missing Phase)
displayed incorrectly
Check that compressor T1 and T3 wires are through module’s current sensing holes. Verify Y ter-
minal is connected to 24VAC at contactor coil. Verify voltage at contactor coil falls below 0.5VAC
when off.
Alert Flash Code *
(Welded Contactor)
displayed incorrectly
Determine if module’s Y terminal is connected. Verify Y terminal is connected to 24VAC at contactor
coil. Verify 24VAC is present across Y and C when thermostat demand signal is present. If not, R
and C are reverse wired. Verify voltage at contactor coil falls below 0.5VAC when off.
High-Pressure Switch —
Compressor Protection
The high-pressure switch is stem mounted on the
discharge line. The switch is a fixed, non-adjustable type.
Compressor Overtemperature Protection (IP) —
A thermostat installed on the compressor motor winding
reacts to excessively high winding temperatures and shuts
off the compressor.
Outdoor Fans —
Each fan is supported by a formed-wire mount bolted to
the fan deck and covered with a wire guard. Fan motors
have permanently lubricated bearings.
Crankcase Heater —
The heater minimizes absorption of liquid refrigerant by
oil in the crankcase during brief or extended shutdown
periods. The heater is wired to cycle with the compressor;
the heater is off when compressor is running, and on when
compressor is off.
1. Shut off unit power supply. Install lockout tag.
2. Remove outdoor fan assembly (grille, motor, and fan).
3. Loosen fan hub setscrews.
4. Adjust fan height as shown in Fig. 33.
5. Tighten setscrews to 84 in-lbs (949 N-cm).
6. Replace outdoor fan assembly.
The crankcase heater will operate as long as the power
circuit is energized. The main disconnect must be on to
energize the crankcase heater.
IMPORTANT: Never open any switch or disconnect
that energizes the crankcase heater unless unit is
being serviced or is to be shut down for a prolonged
period. After a prolonged shutdown on a service job,
energize the crankcase heater for 24 hours before
starting the compressor.
3.6 mm +0/0/-0.8
C10103
Fig. 33 - Outdoor Fan Blade Position
Advanced Scroll Temperature Protection (ASTP) —
Lubrication —
See “Advanced Scroll Temperature Protection (ASTP)” on
page 24.
Fan Motors: The fan motors have sealed bearings. No
provisions are made for lubrication.
Low-Pressure Switch —
Compressor: The compressor has its own oil supply. Loss
of oil due to a leak in the system should be the only
reason for adding oil after the system has been in
operation.
The 38AU low-pressure switch is stem-mounted on the
suction line. Switches are all fixed, non-adjustable type.
37
Condenser Fans/Motors
Access Panel -
Control Box &
Compressors
Service
Valves
C10087
Fig. 34 - 38AUD Size 16 Cabinet
C10095
Fig. 35 - 38AUD*16 Piping
38
Equalization
LPS
Oil Equalizer Line
C10079
Fig. 36 - 38AUZ*16 Compressor Assembly (Rear View)
C10214
Fig. 37 - 38AUD*16 Compressor Assembly (Rear View)
39
Condenser Fans/Motors
Access Panel -
Control Box &
Compressors
Service
Valves
C10089
Fig. 38 - 38AUZ,D Size 25 Cabinet
CKT
1
CKT
2
HPS
HPS
CKT
1
LPS
CKT
2
LPS
C10090
Fig. 39 - 38AUD*25 Piping
40
C10215
Fig. 40 - 38AUZ*25 Compressor Assembly (Rear View)
C10091
Fig. 41 - 38AUD*25 Compressor Assembly (Rear View)
41
Coil Type Identification
38AU units are available with different coil types. Cleaning
methods differ for each type so identifying the coil type is
important. Unit model number and appearance can identify
the coil type.
NOVATIONt Type —
The new NOVATION Heat Exchanger Technology is an
all-aluminum construction with louvered serpentine fins
over single-depth crosstubes. The horizontal crosstubes have
large diameter aluminum headers on each end. Various
optional coatings are also available.
38AU units use two-row segmented coils.
TUBES
FINS
C10216
Fig. 43 - Pivot and Support Top Cover
3. Carefully remove any foreign objects or debris at-
tached to the coil face or trapped within the mounting
frame and brackets.
4. Using a high pressure water sprayer, purge any soap
or industrial cleaners from hose and/or dilution tank
prior to wetting the coil. Clean condenser face by
spraying the coil core steadily and uniformly from top
to bottom, directing the spray straight into or toward
the coil face. Do not exceed 900 psig or a 45 degree
angle; nozzle must be at least 12 in. (30 cm) from the
coil face. Reduce pressure and use caution to prevent
damage to air centers (fins). Do not fracture the braze
between air centers and refrigerant tubes. Allow water
to drain from the coil core and check for refrigerant
leaks prior to start?up.
MANIFOLD
MICROCHANNELS
C07273
Fig. 42 - NOVATION Heat Exchanger Coil
Model number designation: See Fig. 3 for general unit
model number format. Position 11 indicates the coil type
and coating. Position 11 values of G, K, T and W indicate
NOVATION coil type is on this unit.
Round-Tube Plate-Fin (RTPF) Type —
5. Replace top cover and rear corner posts.
This construction uses a series of small diameter copper
hairpin tubes running horizontally with vertical plate fins.
The plate fins may be aluminum (standard) or copper
(optional). Various optional coatings are also available.
These coils may be one-row or two-row.
!
CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage.
Model number designation: See Fig. 3 for general unit
model number format. Position 11 indicates the coil type
and coating. Position 11 values of A, B, C, M, N and P
indicate RTPF coil type is on this unit.
Chemical cleaning should NOT be used on the
aluminum microchannel (NOVATION) condenser.
Damage to the coil may occur. Only approved
cleaning is recommended.
NOVATION Coil Cleaning and Maintenance —
To clean the NOVATION condenser coil, chemicals are
NOT to be used; only water is approved as the cleaning
solution. Only clean potable water is authorized for cleaning
NOVATION condensers.
Repairing NOVATION Condenser Tube Leaks —
RCD offers service repair kit Part Number 50TJ660007 for
repairing tube leaks in the NOVATION coil crosstubes. This
kit includes approved braze materials (aluminum fluxcore
braze rods), a heat shield, a stainless steel brush, replacement
fin segments, adhesive for replacing fin segments, and
instructions specific to the NOVATION aluminum coil. See
EPIC for instruction sheet 99TA526379.
Clean the coil as follows:
1. Turn off unit power.
2. Remove screws holding rear corner posts and top cover
in place. Pivot top cover up 12 to 18 in. (305 to 457
mm) and support with a rigid support. See Fig. 43.
The repair procedure requires the use of MAPP gas and
torch (must be supplied by servicer) instead of conventional
42
oxyacetylene fuel and torch. While the flame temperature
for MAPP is lower than that of oxyacetylene (and thus
provides more flexibility when working on aluminum), the
flame temperature is still higher than the melting
temperature of aluminum, so user caution is required. Follow
instructions carefully. Use the heat shield.
!
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in corrosion
and damage to the unit.
Harsh chemicals, household bleach or acid or basic
cleaners should not be used to clean outdoor or indoor
coils or any kind. These cleaners can be very difficult
to rinse out of the coil and can accelerate corrosion at
the fin/tube interface where dissimilar materials are in
contact. If there is dirt below the surface of the coil
use the Totaline environmentally sound coil cleaner as
described above.
Replacing NOVATIONt Condenser Coil —
The service replacement coil is preformed and is equipped
with transition joints with copper stub tubes. When
brazing the connection joints to the unit tubing, use a wet
cloth around the aluminum tube at the transition joint.
Avoid applying torch flame directly onto the aluminum
tubing.
Routine Cleaning of Round-Tube Plate Fin (RTPF)
Coils —
!
CAUTION
Periodic cleaning with Totaline® environmentally sound coil
cleaner is essential to extend the life of RTPF coils. This
cleaner is available from Carrier Replacement parts division
as part number P902-0301 for a one gallon container, and
part number P902-0305 for a 5 gallon container. It is
recommended that all RTPF coils be cleaned with the
Totaline environmentally sound coil cleaner as described
below.
NOTE: Do NOT use Totaline® environmentally sound coil
cleaner, or any other coil cleaner on NOVATION coils. See
“NOVATION Coil Cleaning and Maintenance” for
instructions on cleaning NOVATION coils.
UNIT RELIABILITY HAZARD
Failure to follow this caution may result in reduced
unit performance.
High velocity water from a pressure washer, garden
hose, or compressed air should never be used to clean
a coil. The force of the water or air jet will bend the
fin edges and increase airside pressure drop.
Totaline Environmentally Sound Coil Cleaner
Application Instructions:
Coil cleaning should be part of the unit’s regularly
scheduled maintenance procedures to ensure long life of
the coil. Failure to clean the coils may result in reduced
durability in the environment.
NOTE: Proper eye protection such as safety glasses is
recommended during mixing and application.
1. Turn off unit power.
2. Remove screws holding rear corner post and top cover
in place. Pivot top cover up 12 to 18 inches (305 to 457
mm) and support with a rigid support. See Fig. 43.
3. Remove all surface loaded fibers and dirt with a vacu-
um cleaner. If a vacuum cleaner is not available, a
soft non-metallic bristle brush may be used. In either
case, the tool should be applied in the direction of the
fins. Coil surfaces can be easily damaged (fin edges
can be easily bent over and damage to the coating of
a protected coil) if the tool is applied across the fins.
NOTE: Use of a water stream, such as a garden hose,
against surface loaded coil will drive the fibers and dirt
into the coil, making cleaning efforts more difficult.
Surface loaded fibers must be completely removed prior
to using low velocity clean water rinse.
Avoid the use of:
S coil brighteners
S acid cleaning prior to painting
S high pressure washers
S poor quality water for cleaning
Totaline environmentally sound coil cleaner is
non-flammable, hypoallergenic, non-bacterial, and a
USDA accepted biodegradable agent that will not harm
the coil or surrounding components such as electrical
wiring, painted metal surfaces, or insulation. Use of
non-recommended coil cleaners is strongly discouraged
since coil and unit durability could be affected.
4. Using a low velocity garden hose thoroughly wet
finned surfaces with clean water. Be careful not to
bend the fins.
5. Mix Totaline environmentally sound coil cleaner in a
21/2 gallon garden sprayer according to the instruc-
tions included with the cleaner. The optimum solution
temperature is 100°F (38°C).
Totaline Environmentally Sound Coil Cleaner
Application Equipment —
S 21/2 gallon garden sprayer
S water rinse with low velocity spray nozzle
NOTE: Do NOT USE water in excess of 130°F (54°C),
as the enzymatic activity will be destroyed.
6. Thoroughly apply Totaline® environmentally sound
coil cleaner solution to all coil surfaces including the
finned area, tube sheets and coil headers.
43
7. Hold garden sprayer nozzle close to finned areas and
apply cleaner with a vertical, up-and-down motion.
Avoid spraying in horizontal pattern to minimize po-
tential for fin damage.
8. Ensure cleaner thoroughly penetrates deep into finned
areas.
9. Interior and exterior finned areas must be thoroughly
cleaned.
10. Finned surfaces should remain wet with cleaning
solution for 10 minutes.
FASTENER TORQUE VALUES
Table 13 – Torque Values
Compressor mounting bolts
Condenser fan motor mounting bolts
Condenser fan hub setscrew
High-flow service port
65---75 in–lbs
(734–847 N–cm)
20 ±2 in–lbs
(226 ±23 N–cm)
84 ±2 in–lbs
(949 ±136 N–cm)
96 ±10 in–lbs
(1085 ±23 N–cm)
11. Ensure surfaces are not allowed to dry before rinsing.
Reapply cleaner as needed to ensure 10-minute satur-
ation is achieved.
12. Thoroughly rinse all surfaces with low velocity clean
water using downward rinsing motion of water spray
nozzle. Protect fins from damage from the spray
nozzle.
Schrader-type service check valve
Compressor oil sightglass thread
2–3 in–lbs
(23–34 N–cm)
330 ±31 in–lbs
(23–34 N–cm)
Compressor to Compressor rail torque 120–168 in–lbs
(1356–1898 N–cm)
Compressor rail to base pan torque
70 ±5 in–lbs
(791 ±57 N–cm)
13. Replace top cover and rear corner posts.
TROUBLESHOOTING
PROBLEM
SOLUTION
COMPRESSOR DOES NOT RUN
Contactor Open
1. Power off.
1. Restore power.
2. Fuses blown in field power circuit.
3. No control power.
2. After finding cause and correcting, replace with correct size fuse.
3. Check control transformer primary connections and circuit breaker.
4. Check thermostat setting.
4. Thermostat circuit open.
5. Safety device lockout circuit active.
6. Low-pressure switch open.
5. Reset lockout circuit.
6. Check for refrigerant undercharge, obstruction of indoor airflow. Make
sure liquid line solenoid valve(s) is open.
7. High-pressure switch open.
7. Check for refrigerant overcharge, obstruction of outdoor airflow, air in system.
Be sure outdoor fans are operating correctly.
8. Compressor overtemperature switch open.
9. Loose electrical connections.
10. Compressor stuck.
8. Check for open condition. Allow for reset. Replace compressor if necessary
9. Tighten all connections.
10. See compressor service literature.
Contactor Closed
1. Compressor leads loose.
2. Motor windings open.
1. Check connections.
2. See compressor service literature.
3. Single phasing.
3. Check for blown fuse. Check for loose connection at compressor terminal.
COMPRESSOR STOPS ON HIGH-PRESSURE SWITCH
Outdoor Fan On
1. High-pressure switch faulty.
2. Reversed fan rotation.
3. Airflow restricted.
1. Replace switch.
2. Confirm rotation, correct if necessary.
3. Remove obstruction.
4. Air recirculating.
4. Clear airflow area.
5. Noncondensables in system.
6. Refrigerant overcharge.
7. Line voltage incorrect.
8. Refrigerant system restrictions.
Outdoor Fan Off
5. Recover refrigerant and recharge as required.
6. Recover refrigerant as required.
7. Consult power company.
8. Check or replace filter drier, expansion valve, etc.
1. Fan slips on shaft.
1. Tighten fan hub setscrews.
2. Check power and capacitor.
3. Replace bearings.
2. Motor not running.
3. Motor bearings stuck.
4. Motor overload open.
5. Motor burned out.
4. Check overload rating. Check for fan blade obstruction.
5. Replace motor.
44
TROUBLESHOOTING (cont)
PROBLEM
SOLUTION
COMPRESSOR CYCLES ON LOW-PRESSURE SWITCH
Indoor-Air Fan Running
1. Liquid line solenoid valve(s) fails to open.
2. Filter drier plugged.
1. Check liquid line solenoid valve(s) for proper operation. Replace if necessary.
2. Replace filter drier.
3. Expansion valve power head defective.
4. Low refrigerant charge.
Airflow Restricted
3. Replace power head.
4. Add charge. Check low-pressure switch setting.
1. Coil iced up.
1. Check refrigerant charge.
2. Clean coil fins.
2. Coil dirty.
3. Air filters dirty.
3. Clean or replace filters.
4. Check damper operation and position.
4. Dampers closed.
Indoor-Air Fan Stopped
1. Electrical connections loose.
2. Fan relay defective.
1. Tighten all connections.
2. Replace relay.
3. Motor overload open.
4. Motor defective.
3. Power supply.
4. Replace motor.
5. Fan belt broken or slipping.
5. Replace or tighten belt.
COMPRESSOR RUNNING BUT COOLING INSUFFICIENT
Suction Pressure Low
1. Refrigerant charge low.
1. Add refrigerant.
2. Head pressure low.
2. Check refrigerant charge. Check outdoor-air fan thermostat settings.
3. Clean or replace filters.
3. Air filters dirty.
4. Expansion valve power head defective.
5. Indoor coil partially iced.
6. Indoor airflow restricted.
Suction Pressure High
4. Replace power head.
5. Check low-pressure setting.
6. Remove obstruction.
1. Heat load excessive.
1. Check for open doors or windows in vicinity of fan coil.
UNIT OPERATES TOO LONG OR CONTINUOUSLY
1. Low refrigerant charge.
1. Add refrigerant.
2. Control contacts fused.
2. Replace control.
3. Air in system.
3. Purge and evacuate system.
4. Clean or replace.
4. Partially plugged expansion valve or filter drier.
SYSTEM IS NOISY
1. Piping vibration.
2. Compressor noisy.
1. Support piping as required.
2. Replace compressor if bearings are worn.
COMPRESSOR LOSES OIL
1. Leak in system.
1. Repair leak.
2. Crankcase heaters not energized during shutdown.
3. Improper interconnecting piping design.
2. Check wiring and relays. Check heater and replace if defective.
3. Check piping for oil return. Replace if necessary.
FROSTED SUCTION LINE
Expansion valve admitting excess refrigerant.
Adjust expansion valve.
HOT LIQUID LINE
1. Shortage of refrigerant due to leak.
2. Expansion valve opens too wide.
1. Repair leak and recharge.
2. Adjust expansion valve.
FROSTED LIQUID LINE
1. Restricted filter drier.
1. Remove restriction or replace.
2. Replace valve.
2. Liquid line solenoid valve partially closed.
45
APPENDIX A
®
S POE oils absorb moisture rapidly. Do not expose oil to
atmosphere.
Air Conditioner & Heat Pump with PURON
— Quick Reference Guide
S Puron® (R-410A) refrigerant operates at 50 percent to
70 percent higher pressures than R-22. Be sure that
servicing equipment and replacement components are
designed to operate with Puron®.
S POE oils may cause damage to certain plastics and
roofing materials.
S Wrap all filter driers and service valves with wet cloth
when brazing.
S A factory approved, liquid-line filter drier is required on
S Puron® refrigerant cylinders are rose colored.
every unit.
S Recovery cylinder service pressure rating must be 400
S Do not use an R-22 TXV.
psig, DOT 4BA400 or DOT BW400.
S If indoor unit is equipped with a TXV, it must be
S Puron® systems should be charged with liquid
refrigerant. Use a commercial type metering device in
the manifold hose when charging into suction line with
compressor operating.
changed to a Puron® TXV.
S Never open system to atmosphere while it is under a
vacuum.
S Manifold sets should be 700 psig high side and 180 psig
low side with 550 psig low-side retard.
S When system must be opened for service, recover
refrigerant, break vacuum with dry nitrogen before
opening system.
S Use hoses with 700 psig service pressure rating.
S Always replace filter drier after opening system for
S Leak detectors should be designed to detect HFC
service.
refrigerant.
S Do not vent Puron® into the atmosphere.
S Puron®, as with other HFCs, is only compatible with
POE oils.
S Do not use capillary tube coils.
S Vacuum pumps will not remove moisture from oil.
S Observe all warnings, cautions, and bold text.
S All Puron® heat pumps must have indoor TXV.
S Use only factory specified liquid-line filter driers with
rated working pressures greater than 600 psig.
S Do not leave Puron® suction line driers in place for
S Do not install a suction-line filter drier in liquid-line.
more than 72 hours.
APPENDIX B
Wiring Diagram List
Unit
Electrical Characteristics
Diagram Number
38AUD*16
208/230-3-60
460-3-60
38AU500540
38AU500541
38AU500542
38AU500565
38AU500566
38AU500567
38AU500537
38AU500538
38AU500539
38AU500568
38AU500569
38AU500570
575-3-60
38AUD*25
38AUZ*16
38AUZ*25
208/230-3-60
460-3-60
575-3-60
208/230-3-60
460-3-60
575-3-60
208/230-3-60
460-3-60
575-3-60
46
APPENDIX C
Troubleshooting —
Low Ambient Option — Factory Installed
OBSERVATION
Fans won’t start
POSSIBLE REMEDY
All fans:
Check power & wiring
Check outdoor fan relay (OFR)
OFM1, OFM3 only:
Check speed control sensor location
Check speed sensor resistance
OFM2, OFM4 only:
Check low ambient switch (LAS)
Check low ambient relay (LAR)
Units with the factory installed low ambient option are
equipped with a MotormasterR solid-state head pressure
control which regulates fan speed. A temperature sensor,
mounted on circuit 1 of the outdoor coil (see Figs. 44 and
45) controls the speed of approved outdoor fan motors in
order to maintain a constant head pressure in the outdoor
coil. The control maintains the appropriate head pressure
at low ambient temperatures down to -20_F (-28_C).
Cooling --- Center outdoor Normal operation
fans (OFM2, OFM4) off
Wind baffles are required to prevent wind cross currents
from causing abnormally low condensing temperatures.
below approximately 60_F
(16_C) outdoor ambient.
S Use 20-gauge sheet metal to fabricate wind baffles (see
Fig. 46 and Table 14) and mounting brackets (see Fig.
47).
Cooling --- Center outdoor
Check low ambient switch (LAS)
fans (OFM2, OFM4) not on Check low ambient relay (LAR)
above approximately 60_F
(16_C) outdoor ambient
NOTE: Mounting brackets are for use on 15 ton model
units only.
Cooling --- Slow fan speed Normal operation
for outer fans (OFM1,
OFM3) at start or during
S Install the wind baffles as show in Fig. 48, for 15 ton
low outdoor ambient
Cooling --- Slow fan speed Check speed control sensor location
units and Fig. 49, for 20 ton units .
for outer fans (OFM1,
Check speed control sensor
OFM3) above 85_F (29_F) resistance
Operation —
outdoor ambient (should
be full speed)
Check fan motor capacitor
Fan on/off control in cooling-only units (38AUZ,
38AUD) is provided by an outdoor fan relay (OFR).
Cooling --- motor current
into speed control is
Normal operation
Up to 30% higher A at partial speed
greater than motor name- at low ambient
plate FLA
In cooling mode, fan motor speed of outdoor motors
OFM1 and OFM3 is regulated by the speed control
temperature sensor on outdoor coil 1 for a minimum coil
condensing temperature of approximately 100_F (38_C)
at higher outdoor ambient temperature and 80_F (27_C) at
lower ambient. Additionally, outdoor fan motor OFM2
and OFM4 are turned on/off by the low ambient
temperature switch, LAS, operating the low ambient relay
(LAR). The LAS control temperatures are open 42_F +/-
5_F, close 57_F +/- 5_F (open 5.5_C +/- 2.8_C, close
13.9_C +/- 2.8_C).
Speed Control Sensor Resistance —
TEMPERATURE
RESISTANCE
_F + / --- 2 _F
--- 2 2
--- 4
_C + / --- 1 _C
Ohms, nominal
88350
48485
27650
16325
9950
--- 3 0
--- 2 0
--- 1 0
0
14
32
50
10
To override the speed control for full fan speed operation
during service or maintenance, either:
68
20
6245
77
25
5000
a. remove sensor and place in hot water >120_F
(>49_C), or
b. rewire to bypass control by connecting speed
control input and output power wires.
86
30
4028
104
122
140
158
40
2663
50
1801
60
1244
70
876
47
Motormaster Sensor -
Must be positioned
on Vapor Stub of
Circuit 1 coil only.
Motormaster
Sensor -
Attach to
Circuit 1 coil only.
508 mm (20 in)
for Single Circuit
254 mm (10 in)
for Dual Circuit
C10093
C10094
Fig. 44 - Motormaster Sensor Location:
38AUZ*16 & 38AUD*16 (Novation)
Fig. 45 - Motormaster Sensor Location:
38AUZ*16/25 & 38AUD*16/25 (RTPF)
48
Table 14 – Wind Baffle Dimension
DIMENSIONS --- INCHES
UNIT
BAFFLE
LEFT SIDE
BACK
A
B
C
D
E
F
G
H
J
---
---
---
---
3
1
1
1
3
1
19
80
38
34
10
80
38
/
/
/
/
/
/
/
20
/
/
21
81
40
35
12
81
40
/
/
/
/
/
/
/
43
43
43
43
43
43
43
43
43
43
43
43
/
/
/
/
/
/
/
/
/
/
/
/
8 /
18
18
27
27
27
25
22
27
27
21
22
22
21
21
/
/
/
/
/
/
/
/
/
/
/
/
40
40
4
4
4
8
4
4
4
2
4
4
4
8
4
4
4
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
8
4
4
4
4
4
4
4
4
4
4
4
4
38AUZ*16
38AUD*16
(MCHX)
1
3
1
3
1
3
3
1
5
1
3
1
1
1
1
1
1
1
1
1
1
1
1
1
3
1
1
3
1
1
1
3
1
1
3
3
81
1
8 /
3
RIGHT SIDE
FRONT
39
8 /
18
1
40
1
2
8
7
7
34 /
1
6 /
16
/
38
/
/
2
2
4
1
1
1
1
LEFT SIDE
BACK
11
/
4 /4
3
13 /4
18
31
40
/
/
2
4
4
38AUZ*16
38AUD*16
(RTPF)
81
8 /
40
---
---
8
8
4
1
3
5
3
RIGHT SIDE
FRONT
39
27
/
2
/
4
8
8 /
18
3
40
3
3
3
27
7
28 /2
3
3 /
12
13
13
12
12
/
/
/
/
/
30
/
/
/
/
/
39
4
4
4
4
4
4
4
4
4
4
1
1
1
3
3
1
1
3
3
1
1
3
3
LEFT SIDE
BACK
32
/
/
/
/
33 /
1
34 /
1
4
4
3
3
/
31
31
30
30
40
40
39
39
/
4
8
4
8
8
8
4
4
4
4
38AUZ*25
38AUD*25
(RTPF)
3
1
1
1
3
3
47
61
20
48
/
49
/
/
/
/
/
/
/
2
8
8
4
8
8
4
4
4
7
5
RIGHT SIDE
FRONT
61 /
62 /
7
5
20 /
21 /
DIMENSIONS --- MM
UNIT
BAFFLE
LEFT SIDE
BACK
A
B
C
D
E
F
G
H
J
501
520
539
1095
1095
1095
1095
1095
1095
1095
1095
1095
1095
1095
1095
212
212
212
174
108
212
212
95
457
457
457
419
337
457
457
324
337
337
324
324
694
694
694
656
565
694
694
552
565
565
552
552
1015
1015
1015
977
---
---
---
---
38AUZ*16
38AUD*16
(MCHX)
2037
983
2056
1002
885
2075
1021
904
RIGHT SIDE
FRONT
866
LEFT SIDE
BACK
272
291
310
794
1022
---
38AUZ*16
38AUD*16
(RTPF)
2037
983
2056
1002
704
2075
1021
723
1015
1015
781
RIGHT SIDE
FRONT
---
684
1010
1022
1022
1010
1010
LEFT SIDE
BACK
834
853
872
108
108
95
794
38AUZ*25
38AUD*25
(RTPF)
1214
1551
510
1233
1570
530
1252
1589
549
794
RIGHT SIDE
FRONT
781
95
781
MCHX: NOVATION coil model
49
50
51
52
53
Catalog No: 38AU---09SI
Copyright 2010 Carrier Corp. D 7310 W. Morris St. D Indianapolis, IN 46231
Printed in U.S.A.
Edition Date: 11/10
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Replaces: 38AU---07SI
54
START-UP CHECKLIST
I. PRELIMINARY INFORMATION
OUTDOOR: MODEL NO.
INDOOR: AIRHANDLER MANUFACTURER
MODEL NO.
SERIAL NO.
SERIAL NO.
ADDITIONAL ACCESSORIES
II. PRE-START-UP
OUTDOOR UNIT
IS THERE ANY SHIPPING DAMAGE?
(Y/N)
IF SO, WHERE:
WILL THIS DAMAGE PREVENT UNIT START-UP?
(Y/N)
CHECK POWER SUPPLY. DOES IT AGREE WITH UNIT?
(Y/N)
HAS THE GROUND WIRE BEEN CONNECTED?
(Y/N)
HAS THE CIRCUIT PROTECTION BEEN SIZED AND INSTALLED PROPERLY?
ARE THE POWER WIRES TO THE UNIT SIZED AND INSTALLED PROPERLY?
(Y/N)
(Y/N)
CONTROLS
ARE THERMOSTAT AND INDOOR FAN CONTROL WIRING CONNECTIONS MADE AND CHECKED?
(Y/N)
ARE ALL WIRING TERMINALS (including main power supply) TIGHT?
HAS CRANKCASE HEATER BEEN ENERGIZED FOR 24 HOURS?
(Y/N)
(Y/N)
INDOOR UNIT
HAS WATER BEEN PLACED IN DRAIN PAN TO CONFIRM PROPER DRAINAGE?
ARE PROPER AIR FILTERS IN PLACE? (Y/N)
HAVE FAN AND MOTOR PULLEYS BEEN CHECKED FOR PROPER ALIGNMENT?
DO THE FAN BELTS HAVE PROPER TENSION? (Y/N)
(Y/N)
(Y/N)
HAS CORRECT FAN ROTATION BEEN CONFIRMED?
(Y/N)
PIPING
ARE LIQUID LINE SOLENOID VALVES LOCATED AT THE INDOOR COILS AS REQUIRED? (Y/N)
HAVE LEAK CHECKS BEEN MADE AT COMPRESSOR, OUTDOOR AND INDOOR COILS,
TXVs (Thermostatic Expansion Valves), SOLENOID VALVES, FILTER DRIERS, AND FUSIBLE PLUGS
WITH A LEAK DETECTOR?
(Y/N)
LOCATE, REPAIR, AND REPORT ANY LEAKS.
HAVE LIQUID LINE SERVICE VALVES BEEN OPENED?
HAVE SUCTION LINE SERVICE VALVES BEEN OPENED?
(Y/N)
(Y/N)
55
CHECK VOLTAGE IMBALANCE
LINE-TO-LINE VOLTS:
(AB + AC + BC)/3 = AVERAGE VOLTAGE =
MAXIMUM DEVIATION FROM AVERAGE VOLTAGE =
VOLTAGE IMBALANCE = 100 X (MAX DEVIATION)/(AVERAGE VOLTAGE) =
AB
V
AC
V
BC
V
V
V
IF OVER 2% VOLTAGE IMBALANCE, DO NOT ATTEMPT TO START SYSTEM!
CALL LOCAL POWER COMPANY FOR ASSISTANCE.
CHECK INDOOR UNIT FAN SPEED AND RECORD.
CHECK OUTDOOR UNIT FAN SPEED AND RECORD.
AFTER AT LEAST 10 MINUTES RUNNING TIME, RECORD THE FOLLOWING MEASUREMENTS:
SUCTION PRESSURE CIR 1:
SUCTION LINE TEMP CIR 1:
CIR 2:
CIR 2:
CIR 2:
CIR 2:
LIQUID PRESSURE
LIQUID LINE TEMP
CIR 1:
CIR 1:
ENTERING OUTDOOR UNIT AIR TEMP
LEAVING OUTDOOR UNIT AIR TEMP
INDOOR UNIT ENTERING-AIR DB (dry bulb) TEMP
INDOOR UNIT ENTERING-AIR WB (wet bulb) TEMP
INDOOR UNIT LEAVING-AIR DB TEMP
INDOOR UNIT LEAVING-AIR WB TEMP
COMPRESSOR 1 AMPS (L1/L2/L3)
COMPRESSOR 2 AMPS (L1/L2/L3)
/
/
/
/
NOTES:
Catalog No: 38AU---09SI
Copyright 2010 Carrier Corp. D 7310 W. Morris St. D Indianapolis, IN 46231
Printed in U.S.A.
Edition Date: 11/10
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Replaces: 38AU---07SI
56
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