Carrier Heat Pump 50ZHA024 060 User Manual

50ZHA024-060

Packaged Heat Pump Units

Visit www.carrier.com

Installation, Start-Up and Service Instructions

NOTE: Read the entire instruction manual before starting the

installation.

TABLE OF CONTENTS

SAFETY CONSIDERATIONS.....................................................1

INTRODUCTION..........................................................................2

RECEIVING AND INSTALLATION ..........................................2

Check Equipment......................................................................2

IDENTIFY UNIT ................................................................2

INSPECT SHIPMENT........................................................2

Provide Unit Support................................................................2

SLAB MOUNT ...................................................................2

GROUND MOUNT ............................................................2

Provide Clearances....................................................................2

Place Unit..................................................................................2

Select and Install Ductwork .....................................................2

CONVERTING HORIZONTAL DISCHARGE

UNITS TO DOWNFLOW (VERTICAL) DIS-

CHARGE ..................................................................4

Provide for Condensate Disposal.............................................4

Install Electrical Connections...................................................5

HIGH-VOLTAGE CONNECTIONS..................................5

ROUTING POWER LEADS INTO UNIT ........................6

A05194

Fig. 1—Unit 50ZHA

CONNECTING GROUND LEAD TO UNIT GROUND.6

ROUTING CONTROL POWER WIRES ..........................6

ACCESSORY ELECTRIC HEAT WIRING .....................6

Indoor Blower and Motor.......................................................15

Outdoor Coil, Indoor Coil, and Condensate Drain Pan ........16

Outdoor Fan ............................................................................16

Electrical Controls and Wiring...............................................16

Refrigerant Circuit ..................................................................17

Indoor Airflow ........................................................................17

Metering Devices....................................................................17

Lubrication ..............................................................................17

Liquid Line Strainer................................................................17

High Flow Valves...................................................................17

PRE-START-UP ............................................................................6

START-UP.....................................................................................7

Check for Refrigerant Leaks ....................................................8

LOCATE AND REPAIR REFRIGERANT LEAKS AND

CHARGE THE UNIT AS FOLLOWS: .............................8

Start-Up Cooling Section and Make Adjustments ..................8

CHECKING COOLING CONTROL OPERATION .........8

Refrigerant Charge....................................................................8

NO CHARGE......................................................................8

LOW CHARGE COOLING ...............................................9

HEATING MODE CHARGE.............................................9

Indoor Airflow and Airflow Adjustments................................9

FOR 208/230-V.................................................................13

Unit Controls...........................................................................13

HIGH-PRESSURE RELIEF VALVE...............................13

LOSS OF CHARGE SWITCH.........................................13

COMPRESSOR OVERLOAD..........................................13

Sequence of Operation............................................................13

FAN OPERATION............................................................13

COOLING..........................................................................14

HEATING..........................................................................14

CONTINUOUS FAN ........................................................14

DEFROST..........................................................................14

ELECTRIC RESISTANCE HEATING............................14

TROUBLESHOOTING ...............................................................17

START-UP CHECKLIST............................................................17

NOTE TO INSTALLER—Before installation, READ THESE

INSTRUCTIONS CAREFULLY AND COMPLETELY. Also,

make sure the User’s Manual and Replacement Guide are left with

the unit after installation.

SAFETY CONSIDERATIONS

Installation and servicing of air-conditioning equipment can be

hazardous due to system pressure and electrical components. Only

trained and qualified workers should install, repair, or service

air-conditioning equipment.

Untrained workers can perform basic maintenance functions of

cleaning coils and filters. All other operations should be performed

by trained service people. When working on air-conditioning

equipment, pay attention to precautions in the literature, tags, and

labels attached to the unit, and other safety precautions that may

apply.

MAINTENANCE.........................................................................15

Air Filter..................................................................................15

Unit Top Removal (Outdoor-Coil Side) ................................15

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.

Book

Tab 6 8

PC 101

Printed in U.S.A.

Catalog No. 50ZHA-1SI

Pg 1

9-05

Replaces: New

Download from Www.Somanuals.com. All Manuals Search And Download.

Table 1—Unit Specifications

UNIT HEIGHT

IN. (MM)

UNIT WEIGHT

CENTER OF GRAVITY IN. (MM)

UNIT

ELECTRICAL CHARACTERISTICS

″A″

50ZHA024

50ZHA030

50ZHA036

50ZHA042

50ZHA048

50ZHA060

208/230-1-60

293

324

377

389

384

433

133

147

171

177

175

197

30.13 (765)

34.13 (867)

42.13 (1070)

14.0 (356)

19.0 (483)

19.0 (438)

19.0 (483)

12.0 (305)

19.8 (503)

21.9 (556)

19.8 (503)

21.9 (556)

are field-installed and must be removed from the indoor blower

compartment prior to start-up, even if they are not used for

installation.

Step 6—Provide for Condensate Disposal

NOTE: Be sure that condensate-water disposal methods comply

with local codes, restrictions, and practices.

When designing and installing ductwork, consider the following:

Unit removes condensate through a 1 3/64-in. ID hole (using

3/4-in. OD piping or tubing) which is located at the end of the unit.

See Fig. 2 for location of condensate connection.

UNIT DAMAGE HAZARD

Failure to follw this caution may result in damage to unit

components. When connecting ductwork to units, do not drill

deeper than 3/4 inch in shaded area shown in Fig. 3 or coil

may be damaged.

19.17

3.92

•

All units should have field-supplied filters installed in the

return-air side of the unit. Recommended sizes for filters are

shown in Table 2.

Avoid abrupt duct size increases and reductions. Abrupt change

in duct size adversely affects air performance.

IMPORTANT: Use flexible connectors between ductwork and

unit to prevent transmission of vibration. Use suitable gaskets to

ensure weathertight and airtight seal. When electric heat is

installed, use fire proof canvas (or similar heat resistant material)

connector between ductwork and unit discharge connection. If

flexible duct is used, insert a sheet metal sleeve inside duct. Heat

resistant duct connector (or sheet metal sleeve) must extend 24–in.

from the unit discharge connection flange into the ductwork.

•

Size ductwork for cooling air quantity (cfm). The minimum air

quantity for proper electric heater operation is listed in Table 3.

Heater limit switches may trip at air quantities below those

recommended.

A05195

•

Insulate and weatherproof all external ductwork. Insulate and

cover with a vapor barrier all ductwork passing through

conditioned spaces. Follow latest Sheet Metal and Air Condi-

tioning Contractors National Association (SMACNA) and Air

Conditioning Contractors Association (ACCA) minimum in-

stallation standards for residential heating and air conditioning

systems.

Secure all ducts to building structure. Flash, weatherproof, and

vibration-isolate duct openings in wall or roof according to

good construction practices.

Fig. 3—Area Not to Be Drilled More Than 3/4-in.

Condensate water can be drained directly onto the roof in rooftop

installations (where permitted) or onto a gravel apron in ground-

level installations. Install a field-supplied condensate trap at end of

condensate connection to ensure proper drainage. Make sure that

the outlet of the trap is at least 1 in. lower than the drain-pan

condensate connection to prevent the pan from overflowing. Prime

the trap with water. When using a gravel apron, make sure it slopes

away from the unit.

•

Figure 4 shows a typical duct system with 50ZHA unit installed.

CONVERTING HORIZONTAL DISCHARGE UNITS TO

DOWNFLOW (VERTICAL) DISCHARGE

If the installation requires draining the condensate water away

from the unit, install a 2-in. trap using a 3/4-in. OD tubing or pipe.

(See Fig. 5 and 6.) Make sure that the outlet of the trap is at least

1 in. lower than the unit drain-pan condensate connection to

prevent the pan from overflowing. Prime the trap with water.

Connect a drain tube using a minimum of 3/4-in. PVC, 3/4-in.

CPVC, or 3/4-in. copper pipe (all field supplied). Do not undersize

the tube. Pitch the drain tube downward at a slope of at least 1 in.

for every 10 ft of horizontal run. Be sure to check the drain tube

for leaks. Prime trap at the beginning of the cooling season

start-up. Allowable glues for condensate trap connection are:

Standard ABS, CPVC, or PVC cement.

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury

or death.

Before performing service or maintenance operations on

system, turn off main power to unit and install lockout tag.

Turn off accessory heater power switch if applicable.

Units are dedicated side supply products. They are not convertible

to vertical air supply. A field-supplied plenum must be used to

convert to vertical air discharge.

Download from Www.Somanuals.com. All Manuals Search And Download.

Table 2—Physical Data

UNIT 50ZHA

024

030

036

042

048

060

OPERATING WEIGHT (lbs)

COMPRESSOR TYPE

293

324

377

389

384

433

Scroll

Ultra Tech Scroll

R-22

REFRIGERANT Charge (lb)

7.5

10.3

11.9

11.4

13.3

Accurater

TXV

REFRIGERANT METERING DEVICE

Orifice ID (in.)

.067

.049

.067

.057

.082

.059

.086

.063

—

Orifice OD (in.)

.070

.073

Copper Tubes, Aluminum Plate Fins

CONDENSER COIL

Rows...Fins/in.

Face Area (sq. ft.)

2...21

11.1

2...21

12.7

2...21

15.8

2...21

15.8

2...21

13.3

2...21

15.8

Propeller

CONDENSER FAN

Nominal Cfm

2600

1/8 (825)

2600

1/8 (825)

3200

1/4 (1100)

3300

1/2 (1100)

Diameter (in.)

Motor HP (RPM)

1/4 (1100)

Copper Tubes, Aluminum Plate Fins

EVAPORATOR COIL

Face Area (sq. ft.)

3...17

4.3

3...17

4.9

4...17

4.9

4...17

6.1

4...17

4.9

4...17

6.1

Direct Drive

Evaporator Blower

Nominal Airflow (CFM)

Size (in.)

800

10 x 8

1/2 (1050)

1000

10 x 8

1/2 (1050)

1200

11 x 9

1400

11 x 9

3/4 (1050)

1600

11 x 10

1 (1050)

1875

11 x 10

1 (1050)

Motor HP (RPM)

3/4 (1050)

Round

CONNECTING DUCT SIZES

Supply Air (in.)

Return Air (in.)

Return-Air Filters (in.)*

Throwaway

24 x 24

24 x 30

30 x 30

*Required filter sizes shown are based on the ARI (Air Conditioning and Refrigeration Institute) rated airflow at a velocity of 300 ft/min for throwaway type or 450 ft/min

for high capacity type. Recommended filters are 1-in. thick.

Step 7—Install Electrical Connections

UNIT DAMAGE HAZARD

Failure to follow these precautions may result in damage to

the unit being installed:

ELECTRICAL SHOCK HAZARD

1. Make all electrical connections in accordance with NEC

ANSI/NFPA (latest edition) and local electrical codes

governing such wiring. In Canada, all electrical connec-

tions must be in accordance with CSA standard C22.1

Canadian Electrical Code Part 1 and applicable local

codes. Refer to unit wiring diagram.

2. Use only copper conductor for connections between

field-supplied electrical disconnect switch and unit. DO

NOT USE ALUMINUM WIRE.

Failure to follow this warning could result in personal injury

or death.

The 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 an electrical wire connected to the unit ground in

the control compartment, or conduit approved for electrical

ground when installed in accordance with NEC (National

Electrical Code), ANSI (American National Standards

Institute)/NFPA (latest edition) (in Canada, Canadian Elec-

trical Code CSA C22.1) and local electrical codes.

3. Be sure that high-voltage power to unit is within operating

voltage range indicated on unit rating plate.

4. Insulate low-voltage wires for highest voltage contained

within conduit when low-voltage control wires are run in

same conduit as high-voltage wires.

5. Do not damage internal components when drilling through

any panel to mount electrical hardware, conduit, etc.

Consult local power company for correction of improper

voltage.

HIGH-VOLTAGE CONNECTIONS

The unit must have a separate electrical service with a field-

supplied, waterproof disconnect switch mounted at, or within sight

from the unit. Refer to the unit rating plate for maximum

fuse/circuit breaker size and minimum circuit amps (ampacity) for

wire sizing. See Table 6 for electrical data.

The field-supplied disconnect may be mounted on the unit over the

high-voltage inlet hole. (See Fig. 2.)

Download from Www.Somanuals.com. All Manuals Search And Download.

CONNECTING GROUND LEAD TO UNIT GROUND

INDOOR

THERMOSTAT

Refer to Fig. 8 and 9. Connect the ground lead to the chassis using

the unit ground in the control box.

ROUTING CONTROL POWER WIRES

RETURN

AIR

Form a drip-loop with the thermostat leads before routing them

into the unit. Route the thermostat leads through grommeted hole

provided in unit into unit control box (See Fig. 7). Connect

thermostat leads and unit power leads as shown in Fig. 9, 10A &

10B.

FROM

POWER

SOURCE

TOP COVER

Route thermostat wires through grommet providing a drip-loop at

the panel. Connect low-voltage leads to the thermostat as shown in

Fig. 10A & 10B.

POWER AND

LOW-VOLTAGE

ENTRY

DISCONNECT

PER NEC*

(UNIT AND

ELECTRIC

HEATER)

COMPOSITE

RUST-PROOF

BASEPAN

Power Wiring

Control Wiring

CONDENSATE

DRAIN

The unit transformer supplies 24-v power for complete system

including accessory electrical heater. Transformer is factory wired

for 230-v operation.

CONNECTION

Condenser Airflow

Evaporator Airflow

*Separate disconnect per NEC

(National Electrical Code) required

for electric heater when single-

point conection is not used.

C00008

ACCESSORY ELECTRIC HEAT WIRING

C00008

Refer to accessory electric heat installation instructions for infor-

mation on installing accessory electric heat. Accessory electric

heat wiring is shown in Fig. 11A, 11B, & 11C.

Fig. 4—Typical installation

1” (25mm) MIN.

TRAP

OUTLET

PRE-START-UP

2” (50mm) MIN.

C99013

FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD

Failure to observe the following warnings could result in

serious injury, death and/or property damage:

1. Follow recognized safety practices and wear protective

goggles when checking or servicing refrigerant system.

2. Do not operate compressor or provide any electric power to

unit unless compressor terminal cover is in place and

secured.

3. Do not remove compressor terminal cover until all electri-

cal sources are disconnected and lockout tag is installed.

4. Relieve all pressure from both high- and low-pressure sides

of the system before touching or disturbing anything inside

terminal box if refrigerant leak is suspected around com-

pressor terminals. Use accepted methods to recover refrig-

erant.

Fig. 5—Condensate Trap (Using Tubing)

TRAP

OUTLET

1" min.

2" min.

C00009

5. Never attempt to repair soldered connection while refrig-

erant system is under pressure.

6. Do not use torch to remove any component. System

contains oil and refrigerant under pressure. To remove a

component, wear protective goggles and proceed as fol-

lows:

Fig. 6—PVC Condensate Trap

Table 3—Minimum Airflow for Safe Electric Heater

Operation (CFM)

a. Shut off electrical power to unit and install lockout tag.

b. Relieve all refrigerant from system using both high- and

low-pressure ports. Use accepted methods to recover

refrigerant.

SIZE

Cfm

024

600

030

750

036

900

042

1050

048

1200

060

1500

c. Cut component connecting tubing with tubing cutter and

remove component from unit.

d. Carefully unsweat remaining tubing stubs when neces-

sary. Oil can ignite when exposed to torch flame.

UNIT DAMAGE HAZARD

Failure to follow this caution may result in unit component

damage. Operation of unit on improper line voltage consti-

tutes abuse and may cause unit damage that could affect

warranty.

Use the Start-Up Checklist supplied at the end of this book and

proceed as follows to inspect and prepare the unit for initial

start-up:

ROUTING POWER LEADS INTO UNIT

1. Remove all access panels.

Use only copper wire between disconnect and unit. The high-

voltage leads should be in a conduit until they enter the unit;

conduit termination at the unit must be watertight. Run the

high-voltage leads through the hole on the control box side of the

unit (see Fig. 7 for location). When the leads are inside the unit,

run leads to the control box (Fig. 8). For single-phase units,

connect leads to the black and yellow wires (see Fig. 9).

2. Read and follow instructions on all DANGER, WARNING,

CAUTION, and INFORMATION labels attached to, or

shipped with unit.

Make the following inspections:

a. Inspect for shipping and handling damages such as broken

lines, loose parts, disconnected wires, etc.

Download from Www.Somanuals.com. All Manuals Search And Download.

Table 4—Required Subcooling

REQUIRED SUBCOOLING °F (°C)

Outdoor Ambient Temperature

Model Size

75 (24)

17.5 (9.7)

21 (11.7)

82 (28)

17 (9.4)

85 (29)

16.5 (9.2)

20 (11.1)

95 (35)

16 8.9)

105 (41)

14 (7.8)

16 (8.9)

048

060

20.5 (11.4)

19 (10.6)

Table 5—Required Liquid Line Temperature

REQUIRED LIQUID LINE TEMPERATURE FOR A SPECIFIC SUBCOOLING (R-22)

Required Subcooling (°F)

Required Subcooling (°C)

Pressure (psig)

Pressure (kPa)

134

141

156

163

170

177

184

191

198

205

213

221

229

237

245

253

262

271

280

289

298

307

317

327

337

347

357

367

280

289

298

307

317

327

337

347

357

367

924

972

1075

1124

1172

1220

1268

1317

1365

1413

1468

1524

1579

1634

1689

1744

1806

1868

1930

1992

2054

2116

2185

2254

2323

2392

2461

2530

1930

1992

2054

2116

2185

2254

2323

2392

2461

2530

101

104

106

108

111

113

116

118

121

123

125

128

130

132

135

137

139

142

121

123

125

128

130

132

135

137

139

142

101

103

106

108

111

113

116

118

120

123

125

127

130

132

134

137

116

118

120

123

125

127

130

132

134

137

101

103

106

108

111

113

115

118

120

122

125

127

129

132

111

113

115

118

120

122

125

127

129

132

101

103

106

108

110

113

115

117

120

122

124

127

106

108

110

113

115

117

120

122

124

127

b. Inspect for oil at all refrigerant tubing connections and on

unit base. Detecting oil generally indicates a refrigerant

leak. Leak-test all refrigerant tubing connections using

electronic leak detector, or liquid-soap solution. If a refrig-

erant leak is detected, see following Check for Refrigerant

Leaks section.

a. Make sure that outdoor-fan blade is correctly positioned in

fan orifice. Top edge of blade should be 3.125 in. down

from outdoor coil outlet grille (size 024–048, See Fig. 12)

or hub should be 0.708-in. away from motor end bell (size

060, See Fig. 13). See Outdoor Fan Adjustment section.

b. Make sure that air filter is in place.

c. Inspect all field- and factory-wiring connections. Be sure

that connections are completed and tight. Ensure wires do

not contact refrigerant tubing or sheet metal edges.

c. Make sure that condensate drain trap is filled with water to

ensure proper drainage.

d. Make sure that all tools and miscellaneous loose parts have

been removed.

d. Inspect coil fins. If damaged during shipping and handling,

carefully straighten fins with a fin comb.

3. Verify the following conditions:

Download from Www.Somanuals.com. All Manuals Search And Download.

LOW -VOLTAGE W IRING

ENTRY HOLE

Step 2—Start-Up Cooling Section and Make Adjustments

HIGH-VOLTAGE POW ER

W IRING ENTRY HOLE

UNIT DAMAGE HAZARD

Failure to follow this caution may result in unit component

damage.

Complete the required procedures given in the Pre-Start- Up

section this page before starting the unit. Do not jumper any

safety devices when operating the unit.

Do not operate the compressor in cooling mode when the

outdoor temperature is below 40 F.

Do not rapid-cycle the compressor. Allow 5 minutes between

‘‘on’’ cycles to prevent compressor damage.

CHECKING COOLING CONTROL OPERATION

Start and check the unit for proper cooling control operation as

follows:

1. Place room thermostat SYSTEM switch in OFF position.

Observe that blower motor starts when FAN switch is placed

in ON position and shuts down within 60 seconds (for

024-042) or 90 seconds (for 048 and 060) when FAN switch

is placed in AUTO position.

2. Place SYSTEM switch in COOL position and FAN switch in

AUTO position. Set cooling control below room temperature.

Observe that compressor, outdoor fan, and indoor blower

motors start and that reversing valve shifts. Observe that

cooling cycle shuts down when control setting is satisfied.

Reversing valve (RV) remains energized.

A05198

Fig. 7—Unit Electrical Connection

3. Place system switch in HEAT position. Observe that compres-

sor, indoor fan and outdoor fan energize (Reversing Valve is

deenergized in heat pump heating mode). Set control above

room temperature. Observe that heating cycle shuts down

when control setting is satisfied.

4. When using an automatic changeover room thermostat, place

both SYSTEM and FAN switches in AUTO. positions.

Observe that unit operates in Cooling mode when temperature

control is set to ‘‘call for cooling’’ (below room temperature),

and unit operates in Heating mode when temperature control

is set to “call for heating” (above room temperature).

Step 3—Refrigerant Charge

Refrigerant Charge — Amount of refrigerant charge is listed on

unit nameplate and in Table 2. Refer to Carrier Refrigerant Service

Techniques Manual, Refrigerants section. Unit panels must be in

place when unit is operating during charging procedure. Unit must

operate a minimum of 15 minutes before checking charge.

C00011

Fig. 8—Control Box Wiring

START-UP

NO CHARGE

Refer to Carrier Refrigerant Service Techniques. Use standard

evacuating techniques. After evacuating system, weigh in the

specified amount of refrigerant (refer to Table 2).

Use the Start-Up Checklist supplied at the end of this book and

proceed as follows:

UNIT GROUND

Step 1—Check for Refrigerant Leaks

GROUND

LEAD

LOCATE AND REPAIR REFRIGERANT LEAKS AND

CHARGE THE UNIT AS FOLLOWS:

SINGLE-PHASE

BLK

YEL

BLU

CONNECTIONS

TO DISCONNECT

PER NEC

3-PHASE

CONNECTIONS

TO DISCONNECT

PER NEC

1. Using both high- and low-pressure ports, locate leaks and

reclaim remaining refrigerant to relieve system pressure.

2. Repair leak following accepted practices.

NOTE: Install a liquid-line filter drier whenever the system has

been opened for repair.

C00012

Fig. 9—Line Power Connections

Download from Www.Somanuals.com. All Manuals Search And Download.

3. Insulate the temperature sensing device so that the outdoor

ambient doesn’t affect the reading.

BROWN

RED

4. Locate the measured suction line pressure in the top row of

Table 8 and the measured outdoor ambient temperature in the

left column of the table. Based on the two values, determine

the required suction line temperature.

5. If the measured suction line temperature is greater than the

tabulated temperature, add charge in the system.

GREEN

048 and 060 units:

1. Measure discharge line pressure by attaching a gauge to the

service port.

YELLOW

2. Measure the liquid line temperature by attaching a temperature

sensing device to it.

ORANGE

3. Insulate the temperature sensing device so that the outdoor

ambient doesn’t affect the reading.

4. Refer to the required subcooling in Tables 4 and 5 to find the

required subcooling based on the model size and the outdoor

ambient temperature.

WHITE

VIOLET

5. Interpolate if the outdoor temperature lies in between the table

values. Extrapolate if the temperature lies beyond the table

range.

Unit Control

Power

Thermostat

and subbase

6. Find the pressure value corresponding to the measured pres-

sure on the compressor discharge line.

7. Read across from the pressure reading to obtain the Liquid line

temperature for a required subcooling.

A05207

Fig. 10A—Control Connections (Sizes 024-042)

8. Add charge if the measured temperature is higher than the

liquid line temperature value in the table.

9. Add charge using the service connection on the suction line of

the compressor.

BROWN

HEATING MODE CHARGE

Do not attempt to adjust charge by cooling methods while in heat

pump heating mode. Recover refrigerant and weigh in according to

unit data plate refrigerant data.

RED

Step 4—Indoor Airflow and Airflow Adjustments

GREEN

NOTE: For cooling operation, the recommended airflow is 350 to

450 cfm per each 12,000 Btuh of rated cooling capacity.

Table 7 shows dry coil air delivery for horizontal discharge units.

Tables 9-11 show pressure drops.

YELLOW

NOTE: Be sure that all supply- and return-air grilles are open,

free from obstructions, and adjusted properly.

PINK

ORANGE

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury

or death.

Disconnect electrical power to the unit and install lockout tag

before changing blower speed.

WHITE

VIOLET

Airflow can be changed by changing the 24 volts lead connections

of the blower motor.

Unit Control

Power

Thermostat

and subbase

Unit 50ZHA blower motors are factory wired for rated airflow

operation.

A05208

FOR 208/230-V BLOWER MOTORS

Fig.10B—Control Connections (Sizes 048-060)

The motor lead speed connections are as follows:

LOW CHARGE COOLING

024-042 units:

SIZE

024

030

036

042

RATED AIRFLOW

Tap 1

HIGH AIRFLOW

Tap 3

1. Measure suction line pressure by attaching a gauge to the

service port.

Tap 2

Tap 4

Tap 1

Tap 3

2. Measure the suction line temperature by attaching a tempera-

ture sensing device to it.

Tap 2

Tap 4

Download from Www.Somanuals.com. All Manuals Search And Download.

A05199

Fig. 11A—Typical Unit Electrical Diagram (Sizes 024-042)

Download from Www.Somanuals.com. All Manuals Search And Download.

A05200

Fig. 11B—Typical Unit Electrical Diagram (Sizes 048-060)

Download from Www.Somanuals.com. All Manuals Search And Download.

A05209

Fig. 11C—Accessory Electric Heater Wiring

Table 6—Electrical Data—50ZHA

VOLTAGE

RANGE

COMPRESSOR

ELECTRIC HEAT

Nominal KW* FLA

SINGLE POINT POWER SUPPLY

UNIT SIZE

50ZHA

OFM

FLA

IFM

FLA

V-PH-HZ

FUSE OR

CKT BKR

MIN

MAX

RLA

10.9

LRA

54.0

MCA

MOCP

—/—

3.8/5.0

7.5/10.0

5.4/7.2

—/—

18.6/18.6

41.2/44.7

63.8/70.7

51.1/56.1

25/25

45/50

—

60/70

—

18.1/20.8

36.1/41.7

26.0/30.0

024

030

208/230–1–60

187

253

0.9

4.1

50/50

—/—

3.8/5.0

7.5/10.0

11.3/15.0

5.4/7.2

—/—

21.8/21.8

44.4/47.9

57.0/73.9

89.5/100.0

54.3/59.3

30/30

50/50

—

60/60

—

70/70

90/100

—

18.1/20.8

36.1/41.7

54.2/62.5

26.0/30.0

208/230–1–60

253

13.5

17.5

72.5

88.0

—/—

3.8/5.0

7.5/10.0

11.3/15.0

5.4/7.2

—/—

29.4/29.4

52.0/55.4

74.5/81.5

97.1/107.5

61.9/66.9

35/35

60/60

—

80/80

100/100

70/70

18.1/20.8

36.1/41.7

54.2/62.5

26.0/30.0

036

042

187

1.5

6.0

—/—

3.8/5.0

7.5/10.0

11.3/15.0

15.0/20.0

5.4/7.2

—/—

31.7/31.7

54.3/57.8

76.9/83.8

99.4/109.9

122.0/135.9

63.2/69.2

40/40

—

60/70

80/90

100/110

110/150

70/80

18.1/20.8

36.1/41.7

54.2/62.5

72.2/83.3

26.0/30.0

208/230–1–60

253

19.4

24.7

28.0

104.0

116.0

118.0

—

—/—

3.8/5.0

7.5/10.0

11.3/15.0

15.0/20.0

5.4/7.2

—/—

40.0/40.0

62.6/66.1

85.1/92.1

107.7/118.1

130.3/144.2

72.5/77.5

50/50

—

80/80

100/100

110/125

125/125

90/90

18.1/20.8

36.1/41.7

54.2/62.5

72.2/83.3

26.0/30.0

048

060

187

1.5

3.0

7.7

—

3.8/5.0

7.5/10.0

11.3/15.0

15.0/20.0

5.4/7.2

—/—

45.7/45.7

68.2/71.7

90.8/97.8

113.4/123.8

135.9/149.9

78.2/83.2

60/60

—

90/90

100/110

125/125

125/150

90/100

18.1/20.8

36.1/41.7

54.2/62.5

72.2/83.3

26.0/30.0

—

FLA Full Load Amps

LRA Locked Rotor Amps

MCA Minimum Circuit Amps

MOCP Maximum Overcurrent Protection

RLA Rated Load Amps

NOTES:

1. In compliance with NEC (National Electrical Code) requirements for multimotor and combination load equipment (refer to NEC Articles 430 and 440), the overcurrent

protective device for the unit shall be Power Supply fuse. The CGA (Canadian Gas Association) units may be fuse or circuit breaker.

2. Minimum wire size is based on 60 C copper wire. If other than 60 C wire is used, or if length exceeds wire length in table, determine size from NEC.

Download from Www.Somanuals.com. All Manuals Search And Download.

Table 7—Dry Coil Air Delivery* Horizontal Discharge

(Deduct 10 percent for 208 Volt Operation)

EXTERNAL STATIC PRESSURE

50ZHA

024

SPEED TAP

WATTS/C.F.M

0.1

0.2

.03

100

793

0.4

118

757

0.5

130

698

0.6

142

632

222

970

0.7

0.8

0.9

1.0

Watts

C.F.M.

Watts

C.F.M

Watts

C.F.M

Watts

C.F.M.

Watts

C.F.M.

Watts

C.F.M.

Watts

C.F.M.

Watts

C.F.M.

Watts

C.F.M.

Watts

C.F.M.

Watts

C.F.M.

Watts

C.F.M.

Watts

C.F.M.

Watts

C.F.M.

Watts

C.F.M.

Watts

C.F.M.

848

233

918

244

861

257

795

260

729

155

1108

146

995

157

951

170

884

030

036

042

261

1117

216

1051

290

1272

349

1273

465

1475

236

932

266

1025

435

1515

469

1612

291

1157

325

1232

685

1789

817

1934

275

1053

286

1014

291

980

315

877

180

1344

166

1215

179

1172

191

1136

261

1343

321

1333

432

1543

216

1027

245

1122

418

1583

457

1684

266

1224

301

1296

660

1844

787

2001

204

1095

276

1304

336

1301

450

1504

229

994

254

1066

425

1555

462

1651

277

1181

311

1261

668

1817

799

1971

301

1234

360

1239

480

1441

249

881

276

954

438

1477

477

1573

298

1117

333

1199

697

1755

826

1899

316

1190

329

1148

342

1100

269

1440

283

1404

305

1369

418

1572

209

1087

233

1164

409

1625

448

1717

251

1259

286

1333

643

1878

770

2028

490

1418

—

503

1380

—

518

1332

—

204

1129

—

289

906

441

1444

480

1537

—

048

386

1680

—

398

1652

440

1745

235

1288

451

1403

485

1508

—

486

—

1470

224

1334

344

1170

370

1062

060

608

1931

737

2093

626

1900

755

2061

812

1850

782

1757

Air delivery values are based on operating voltage of 230-v., dry coil, without filter or electric heater. Deduct wet coil, filter, and electric heater pressure drops to obtain

external static pressure availabe for ducting.

Do not operate the unit at a cooling airflow that is less than 350 cfm for each 12,000 Btuh of rated cooling capacity. Evaporator coil frosting may occur at airflows below

this point.

Dashes indicate portions of the table that are beyond the blower motor capacity or are not recommended.

This overload may require up to 60 minutes (or longer) to reset;

therefore, 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.

RATED AIRFLOW

HIGH AIRFLOW

SIZE

Low

High

Stage

Low

High

Stage

048

060

Tap 1

Tap 3

Tap 2

Tap 4

Step 6—Sequence of Operation

FAN OPERATION

Step 5—Unit Controls

The FAN switch on the thermostat controls indoor fan operation.

When the FAN switch is placed in the ON position, the IFR

(indoor-fan relay) is energized through the G terminal on the

thermostat. The normally-open contacts close, which then provide

power to the indoor (evaporator) fan motor (IFM). The IFM will

run continuously when the FAN switch is set to ON.

All compressors have the following internal-protection controls.

HIGH-PRESSURE RELIEF VALVE

This valve opens when the pressure differential between the low

and high side becomes excessive.

LOSS OF CHARGE SWITCH

When the FAN switch is set to AUTO, the thermostat deenergizes

the IFR (provided there is not a call for cooling). The contacts open

and the IFM is deenergized. The IFM will be energized only when

there is a call for cooling, in heat pump heating mode or if the unit

is equipped with accessory electric heat, the indoor-fan motor will

also run while the accessory electric heat is energized.

Located on the outdoor liquid line is a low-pressure switch which

functions as a loss-of-charge switch. This switch contains a

Schrader core depressor. This switch opens at 7 psig and closes at

22 psig. No adjustment is necessary.

COMPRESSOR OVERLOAD

This overload interrupts power to the compressor when either the

current or internal temperature become excessive, and automati-

cally resets when the internal temperature drops to a safe level.

NOTE: Some units are equipped with a time-delay relay. On

these units, the indoor fan remains on for 30 seconds after G or Y

is deenergized.

Download from Www.Somanuals.com. All Manuals Search And Download.

Table 8—Cooling Charging Chart

SUCTION LINE TEMPERATURE (°F)

Suction Line Pressure (PSIG)

OD Temp. (°F)

—

105

115

125

SUCTION LINE TEMPERATURE (°C)

Suction Line Pressure (kPa)

OD Temp. (°C)

361

—

370

—

387

—

405

—

423

—

442

—

462

—

482

—

502

—

523

—

544

—

566

—

589

—

612

—

636

—

COOLING OPERATION (SIZES 024-042)

heating (Y2) energizes switching the compressor into high stage

heating through energizing an internal solenoid valve inside the

scroll compressor and switching the indoor fan into high stage. The

auxiliary or backup heat is controlled by a third stage (W2). If the

demand is not met, W3 is energized in case of staged heating.

When heating demand is satisfied, W3, W2 and Y2 sequentially

de-energize switching the compressor and the indoor fan into low

stage heating. When the low stage heating demand is met, Y1

de-energizes shutting the compressor, indoor fan and the outdoor

fan.

With a call for cooling (Y/Y2), the indoor fan energizes immedi-

ately whereas the contactor energizes after a 5 minute time delay

(in case of initial start-up) starting the compressor and the outdoor

fan motor. When the cooling demand is met, Y/Y2 de-energizes,

shutting the compressor, indoor fan and the outdoor fan.

COOLING OPERATION (SIZES 048 AND 060)

These units utilize a 2 stage indoor thermostat. With a first stage

call for cooling (Y1), the indoor fan (low stage) energizes

immediately whereas the contactor energizes after a 5 minute time

delay (in case of an initial start-up) starting the compressor (low

stage) and the outdoor fan motor. If the low stage operation cannot

satisfy the cooling demand, the second stage cooling (Y2) ener-

gizes switching the compressor into high stage cooling through

energizing an internal solenoid valve inside the scroll compressor

and switching the indoor fan into high stage. When second stage

cooling is satisfied, Y2 de-energizes switching the compressor and

the indoor fan into low stage cooling. When the low stage cooling

demand is met, Y1 de-energizes shutting the compressor, indoor

fan and the outdoor fan.

CONTINUOUS FAN

With the continuous Indoor fan option selected on the thermostat,

G is continuously energized. In case of 024-042 units, the selected

airflow setting is provided. In case of 048 and 060 units, the

system runs low stage (Y1) airflow for continuous fan operation.

DEFROST

Defrost board (DB) is a time and temperature control, which

includes a field-selectable time period between checks for defrost

(30, 60, 90 and 120 minutes). The time period is factory-set at 60

minutes and should only be adjusted by a trained service person.

Electronic timer and defrost cycle start only when contactor is

energized and defrost thermostat (DFT) is closed.

HEATING OPERATION (SIZES 024-042)

With a call for heating (Y1), the indoor fan (low stage) energizes

immediately whereas the contactor energizes after a 5 minute time

delay (in case of initial start-up) starting the compressor and the

outdoor fan motor. If Y/Y2 cannot satisfy the heating demand, the

auxiliary or backup heat (W2) energizes. In case of staged heating,

W3 is energized if the demand is not met. The highest airflow

selected is run while the electric heat is in operation. When heating

demand is met, W3, W2 and Y/Y2 sequentially de-energize

shutting the compressor, indoor fan and the outdoor fan.

Defrost mode is identical to Cooling mode. The outdoor fan motor

stops because of “OF1” and “OF2” contacts opening on the defrost

board, a bank of optional electric heat turns on to warm air

supplying the conditioned space.

ELECTRIC RESISTANCE HEATING

If accessory electric heaters are installed, on a call for “Emergency

Heat” the thermostat energizes W which energizes the heater relay

and in turn energizes the electric heaters. The IFR is energized

which starts the indoor-fan motor. If the heaters are staged, W2 is

energized when the second stage of heating is required. When the

need for heating is satisfied, the heater and IFM are de-energized.

HEATING OPERATION (SIZES 048 AND 060)

With a first stage call for heating (Y1), the indoor fan (low stage)

energizes immediately whereas the contactor energizes after a 5

minute time delay (in case of initial start-up) starting the compres-

sor (low stage) and the outdoor fan motor. If the low stage

oepration cannot satisfy the heating demand, the second stage

MAINTENANCE

To ensure continuing high performance, and to reduce the possi-

bility of premature equipment failure, periodic maintenance must

Download from Www.Somanuals.com. All Manuals Search And Download.

be performed on this equipment. This cooling unit should be

inspected at least once each year by a qualified service person. To

troubleshoot cooling of units, refer to Troubleshooting chart in

back of book.

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury

or death.

Disconnect and tag electrical power to the unit before

removing top.

NOTE TO EQUIPMENT OWNER: Consult your local dealer

about the availability of a maintenance contract.

Only qualified service personnel should perform maintenance and

service procedures that require unit top removal.

FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury,

death or property damage.

The ability to properly perform maintenance on this equip-

ment requires certain expertise, mechanical skills, tools and

equipment. If you do not possess these, do not attempt to

perform any maintenance on this equipment, other than those

procedures recommended in the User’s Manual.

Refer to the following top removal procedures:

1. Remove screws on unit top cover surface. (Save all screws.)

2. Remove screws on unit top cover flange. (Save all screws.)

3. Lift top from unit carefully. Set top on edge and make sure

that top is supported by unit side that is opposite duct (or

plenum) side.

4. Carefully replace and secure unit top to unit, using screws

removed in Steps 1 and 2, when maintenance and/or service

procedures are completed.

The minimum maintenance requirements for this equipment are as

follows:

1. Inspect air filter(s) each month. Clean or replace when

necessary.

Step 3—Indoor Blower and Motor

2. Inspect indoor coil, outdoor coil, drain pan, and condensate

drain each cooling and heating season for cleanliness. Clean

when necessary.

For longer life, operating economy, and continuing efficiency,

clean accumulated dirt and grease from the blower wheel and

motor annually.

3. Inspect blower motor and wheel for cleanliness each cooling

and heating season. Clean when necessary. For first heating

season, inspect blower wheel bimonthly to determine proper

cleaning frequency.

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury

or death.

Disconnect and tag electrical power to the unit before

cleaning the blower wheel.

4. Check electrical connections for tightness and controls for

proper operation each cooling season. Service when neces-

sary.

5. Check the drain channel in the top cover periodically for

blockage (leaves, insects). Clean as needed.

To clean the blower wheel follow the following steps:

1. Remove the blower housing:

a. Remove the screws on the external side of the duct panel

that fasten the housing to the duct panel assembly.

FIRE, EXPLOSION, ELECTRICAL SHOCK, CUT HAZ-

ARD

b. Remove the side access panel and unscrew the mounting

bracket that fastens the blower housing to the internal

partition panel fo the control box assembly.

Failure to follow these warnings could result in serious

personal injury, death, and/or property damage:

1. Turn off electrical power to the unit and install lockout tag

before performing any maintenance or service on the unit.

2. Use extreme caution when removing panels and parts. As

with any mechanical equipment, personal injury can result

from sharp edges, etc.

c. Make sure that the blower housing is supported by hand

before completely removing the mounting bracket.

d. Slide the blower housing from the rails of the duct panel

and place it outside the unit.

3. Never place anything combustible either on, or in contact

with, the unit.

2. Remove the blower wheel from the housing:

a. Loosen the set screw which secures the wheel to the motor

shaft.

Step 1—Air Filter

b. Loosen the three mounting legs of the motor by removing

the bolts that fasten themounting legs to the housing.

NOTE: Never operate the unit without a suitable air filter in the

return-air duct system. Always replace the filter with the same size

as originally installed. See Table 2 for recommended filter sizes.

c. Slide out the motor assembly (motor, belly band and the 3

mounting legs) from the hub of the wheel.

Inspect air filter(s) at least once each month and replace

(throwaway-type) or clean (cleanable-type) at least twice during

each cooling season or whenever the filters become clogged with

dust and lint.

d. Remove the filler panel at the discharge end of the blower

housing by removing the two screws that fasten it to the

housing.

Replace filters with the same dimensional size and type as

originally provided, when necessary.

e. Remove the wheel form the housing.

3. Remove the caked on dirt from the wheel and the motor using

a brush.

Step 2—Unit Top Removal (Outdoor-Coil Side)

NOTE: When performing maintenance or service procedures that

require removal of the unit top, be sure to perform all of the routine

maintenance procedures that require top removal, including coil

inspection and cleaning, and condensate drain pan inspection and

cleaning.

4. Remove lint and dirt accumulations from the wheel and

housing with a vacuum cleaner, using a soft brush attachment.

5. Remove grease and oil with a mild solvent.

6. Reassemble

Download from Www.Somanuals.com. All Manuals Search And Download.

Table 9—Wet Coil Pressure Drop

STANDARD CFM (S.C.F.M.)

UNIT SIZE

600

700

800

900

.047

.050

1000

.053

.055

.042

1100

1200

1300

1400

1500

1600

1700

1800

1900

2000

024

030

036

042

048

060

.027

.034

040

.036

.042

.063

.049

.072

.052

.072

.081

.059

.081

.090

.065

.090

.097

.071

.097

.071

.078

.108

.078

.085

.120

.085

.091

.129

.091

.139

.098

.114

a. Slip the wheel back in the housing with the hub set screw

parented in the correct direction.

coil fins from inside to outside the unit. On units with an outer and

inner outdoor coil, be sure to clean between the coils. Be sure to

flush all dirt and debris from the unit base.

b. Install the filler panel.

Inspect the drain pan and condensate drain line when inspecting

the coils. Clean the drain pan and condensate drain by removing all

foreign matter from the pan. Flush the pan and drain tube with

clear water. Do not splash water on the insulation, motor, wiring,

or air filter(s). If the drain tube is restricted, clear it with a

‘‘plumbers snake’’ or similar probe device. Ensure that the

auxiliary drain port above the drain tube is also clear.

c. Reinsert the motor assembly in the wheel hub and align the

mounting legs with the housing mounting hold locations.

d. Tighten the mounting bolts to fasten the motor assembly

with the housing.

e. Center the wheel in the housing by sliding it, align the flat

end of the shaft with the set screw and tighten the set screw.

f. Slide back the blower housing into the mounting rails in the

duct panel and install the mounting bracket back in its

position.

Step 5—Outdoor Fan

g. Install the screws on the external side of the duct panel to

fasten duct panel with the housing.

UNIT OPERATIONAL HAZARD

Failure to follow this caution may result in damage to unit

components.

Keep the Outdoor fan free from all obstructions to ensure

proper cooling operation. Never place articles on top of the

unit.

h. Replace the side access panel.

Step 4—Outdoor Coil, Indoor Coil, and Condensate

Drain Pan

Inspect the outdoor coil, indoor coil, and condensate drain pan at

least once heating and cooling season. Proper inspection and

cleaning requires the removal of the unit top. See Unit Top

Removal section.

1. Shut off unit power supply and install lockout tag.

2. Remove outdoor-fan assembly (grille, motor, motor cover,

and fan) by removing screws and flipping assembly onto unit

top cover.

Table 10—Filter Pressure Drop (in. wg)

3. Loosen fan hub setscrews.

FILTER

SIZE

(IN.)

CFM

500 600 700 800 900 1000 1100 1200 1300 1400

UNIT

SIZE

4. Adjust fan height as shown in Fig. 12 or 13.

5. Tighten setscrews.

024-036 24 x 24 0.06 0.07 0.08 0.08 0.09 0.09 0.09 0.10 0.11 0.12

042-060 30 x 30

0.08 0.09

6. Replace outdoor-fan assembly.

Step 6—Electrical Controls and Wiring

FILTER

UNIT

CFM

1500 1600 1700 1800 1900 2000 2100 2200 2300

Inspect and check the electrical controls and wiring annually. Be

sure to turn off the electrical power to the unit and install lockout

tag.

SIZE

(IN.)

024-036 24 x 24 0.14 0.15

042-060 30 x 30 0.10 0.11 0.12 0.13 0.14 0.15 0.16 0.17 0.18

Remove the top panel to locate all the electrical controls and

wiring. Check all electrical connections for tightness. Tighten all

screw connections. If any smoky or burned connections are

noticed, disassemble the connection, clean all the parts, restrip the

wire end and reassemble the connection properly and securely.

Table 11—Accessory Electric Heat Pressure Drop

(in. wg)

CFM

HEATER KW

600 800 1000 1200 1400 1600 1800 2000 2200

5-20

3.125 in.

0.06 0.08 0.10 0.13 0.15 0.18 0.20 0.23 0.25

Remove all obstructions (including weeds and shrubs) that inter-

fere with the airflow through the outdoor coil. Straighten bent fins

with a fin comb. If coated with dirt or lint, clean the coils with a

vacuum cleaner, using a soft brush attachment. Be careful not to

bend the fins. If coated with oil or grease, clean the coils with a

mild detergent-and-water-solution. Rinse coils with clear water,

using a garden hose. Be careful not to splash water on motors,

insulation, wiring or air filter(s). For best results, spray outdoor-

C00021

Fig. 12—Outdoor-Fan Adjustment (024–048 Size)

Check to ensure no wires are touching refrigerant tubing or sharp

sheet metal edges. Move and secure wires to isolate from tubing

and sheet metal edges.

Download from Www.Somanuals.com. All Manuals Search And Download.

and that the air filter is clean. When necessary, refer to Indoor

Airflow and Airflow Adjustments section to check the system

airflow.

Step 9—Metering Devices

Refrigerant cooling metering device is an Accurator (024-042) or

TXV (048 and 060) located upstream of the indoor coil distributor

assembly. Refrigerant heating mode metering device is an Accu-

rater located upstrem of the outdoor coil distributor assembly.

0.708in.

C02017

Step 10—Lubrication

COMPRESSOR—The compressor is charged with the correct

amount of oil at the factory.

Fig. 13—Outdoor-Fan Adjustment (060 Size)

After inspecting the electrical controls and wiring, replace all the

panels. Start the unit, and observe at least one complete cooling

cycle to ensure proper operation. If discrepancies are observed in

operating cycle, or if a suspected malfunction has occurred, check

each electrical component with the proper electrical instrumenta-

tion. Refer to the unit wiring label when making these checkouts.

FAN MOTOR BEARINGS—Fan motor bearings are perma-

nently lubricated. No further lubrication of outdoor or indoor fan

motors is required.

Step 11—Liquid Line Strainer

The liquid line strainer (to protect metering device) is made of wire

mesh and is located in the liquid line on the inlet side of the

metering device.

NOTE: Refer to the Sequence of Operation section, as an aid in

determining proper control operation.

Check valves are also located in the liquid lines near the strainers.

The Strainers are the larger of the two components.

Step 7—Refrigerant Circuit

Inspect all refrigerant tubing connections and the unit base for oil

accumulations annually. Detecting oil generally indicates a refrig-

erant leak.

Step 12—High Flow Valves

Located on the compressor hot gas and suction tubes are High

Flow Valves. Large black plastic caps distinguish these valves

with O-rings located inside the caps. These valves cannot be

accessed for service in the field. Ensure the plastic caps are in

place and tight or the possibility of refrigerant leakage could occur.

If oil is detected or if low cooling performance is suspected,

leak-test all refrigerant tubing using an electronic leak-detector, or

liquid-soap solution. If a refrigerant leak is detected, refer to Check

for Refrigerant Leaks section. (See Table of Contents for page

number.)

TROUBLESHOOTING

If no refrigerant leaks are found and low cooling performance is

suspected, refer to Refrigerant Charge. (See Table of Contents for

page number.)

Use the Troubleshooting Cooling and Heating guide if problems

occur with these units.

START-UP CHECKLIST

Step 8—Indoor Airflow

Use the Start-Up checklist to ensure proper start-up procedures are

followed.

The cooling airflow does not require checking unless improper

performance is suspected. If a problem exists, be sure that all

supply- and return-air grilles are open and free from obstructions,

Download from Www.Somanuals.com. All Manuals Search And Download.

OUTDOOR COIL

INDOOR COIL

LCS

Check Valves

STRAINER

Open

Closed

Open

Closed

LEGEND

LCS

Loss of Charge Switch

Acutrol Metering Device

Check Valve (Arrow indicates direction of flow)

HEATING CYCLE

1. Hot gas from compressor flows through the 4-way valve and is

directed to the cooling liquid line check valve. It is then condensed

and directed through subcooling circuits and out to the strainer

and the check valve in the heating liquid line.

2. The refrigerant then feeds the outdoor coil through the Acutrol

metering device on each circuit.

3. Each circuit evaporates the refrigerant and the circuits are com-

bined in the outdoor header with some of the circuits flowing through

the check valve.

4. The refrigerant then flows through the 4-way valve, accumulator,

and back to the compressor.

C95045

Fig. 14—Typical Heat Pump Operation, Heating Mode

OUTDOOR COIL

INDOOR COIL

LCS

Check Valves

STRAINER

Closed

Open

Closed

Open

LEGEND

LCS

Loss of Charge Switch

Acutrol Metering Device

Check Valve (Arrow indicates direction of flow)

COOLING CYCLE

1. Hot gas from compressor flows through the 4-way valve and is

directed to the heating liquid line check valve. It is then con-

densed and subcooled through converging circuits. Refrigerant leaves

the outdoor coil by way of the strainer and the check valve in the

cooling liquid line.

2. The refrigerant then feeds the indoor coil through the Acutrol

metering device on each circuit.

3. Each circuit evaporates the refrigerant and the circuits are com-

bined in the indoor coil header with some of the circuits flowing

through the check valve.

4. The refrigerant then flows through the 4-way valve, accumulator,

and back to the compressor.

C95044

Fig. 15—Typical Heat Pump Operation, Cooling Mode

Download from Www.Somanuals.com. All Manuals Search And Download.

Table 12—Troubleshooting—Cooling and Heating

SYMPTOM

CAUSE

REMEDY

Power Failure

Call power company

Loss of Charge

Switch open

Evaluate unit for possible refrigerant leak

Replace fuse or reset circuit breaker

Replace component

Fuse blown or circuit breaker tripped

Defective thermostat, contractor, transformer, or

control relay

Compressor and outdoor fan will not start.

Insufficient line voltage

Incorrect or faulty wiring

Determine cause and correct

Check wiring diagram and rewire correctly

Lower thermostat setting below room tempera-

ture

Thermostat setting too high

Faulty wiring or loose connections in compressor

circuit

Check wiring and repair or replace

Compressor motor burned out, seized, or internal

overload open

Determine cause

Replace compressor

Compressor will not start but outdoor fan

runs.

Defective run/start capacitor, overload, start relay

Determine cause and replace

Low input voltage

(20 percent low)

Determine cause and correct

Recover refrigerant, evacuate system, and re-

charge to capacities shown on nameplate

Refrigerant overcharge or undercharge

Loss of Charge

Switch open

Evaluate unit for possible refrigerant leak

Defective compressor

Insufficient line voltage

Replace and determine cause

Determine cause and correct

Compressor cycles

(other than normally satisfying thermostat).

Blocked outdoor coil (cooling)

Defective run/start capacitor, overload or start

relay

Determine cause and replace

Defective thermostat

Faulty outdoor-fan motor or capacitor

Restriction in refrigerant system

Dirty air filter

Replace thermostat

Replace

Locate restriction and remove

Replace filter

Unit undersized for load

Thermostat set too low

Decrease load or increase unit size

Reset thermostat

Low refrigerant charge

Locate leak, repair, and recharge

Replace compressor

Leaking valves in compressor

Compressor operates continuously.

Frosted outdoor coil with incorrect

defrost operation (heating)

Check defrost time settings. Reset as necessary.

Check defrost temperature switch. Replace as necessary.

Recover refrigerant, evacuate system, and re-

charge

Air in refrigerant system

outdoor coil dirty or restricted

Dirty air filter

Clean coil or remove restriction

Replace filter

Dirty outdoor coil

Clean coil

Refrigerant overcharged

Recover excess refrigerant

Excessive head pressure.

Recover refrigerant, evacuate system, and re-

charge

Air in refrigerant system

Outdoor or indoor air restricted

or air is recirculating

Determine cause and correct

Low refrigerant charge

Compressor valves leaking

Restriction in liquid tube

High heat load

Check for leaks, repair and recharge

Replace compressor

Head pressure too low.

Remove restriction

Check for source and eliminate

Replace compressor

Excessive suction pressure.

Compressor valves leaking

Refrigerant overcharged

Dirty air filter (cooling)

Recover excess refrigerant

Replace Filter

Low refrigerant charge

Check for leaks, repair, and recharge

Remove source of restriction

Metering device or low side restricted

Increase air quantity

Check filter- replace if necessary

Suction pressure too low.

Insufficient indoor airflow (cooling)

Temperature too low in conditioned area (cooling)

Outdoor ambient below 40°F (cooling)

Field-installed filter-drier restricted

Reset thermostat

Install low-ambient kit

Replace

Compressor runs but

outdoor fan does not.

Normally closed contacts on

defrost board open

Check condition of relay on board.

Replace board if necessary.

Download from Www.Somanuals.com. All Manuals Search And Download.

START-UP CHECKLIST

(REMOVE AND STORE IN JOB FILE)

I. PRELIMINARY INFORMATION

Model No .............................................................................................................................................................

Serial No ..............................................................................................................................................................

Date ......................................................................................................................................................................

Technician ...........................................................................................................................................................

Customer Information(Name/Address) ...........................................................................................................................................................

II. PRE-START-UP

____ Verify that all packing materials have been removed from unit

____ Verify that condensate connection is installed per installation instructions

____ Check all electrical connections and terminals for tightness

____ Check wire proximity to refrigerant tubes and sheet metal edges

____ Check that indoor (indoor) air filter is clean and in place

____ Verify that unit installation is level

____ Check fan wheel propeller for location in housing and setscrew tightness

III. START-UP

Supply Voltage: L1-L2 __________ L2-L3 __________ L3-L1 __________

Compressor Amps: L1(C) __________ L2(S) __________ L3(R) __________

Indoor Fan Amps: __________ Outdoor Fan Amps: __________

TEMPERATURE-Cooling Mode

Outdoor Air Temperature: __________ DB ____________WB

Return-Air Temperature: __________ DB __________ WB

Cooling Supply Air: __________DB___________WB

PRESSURES-Cooling Mode

Refrigerant Suction __________ psig

Suction Line Temp* ___________

Refrigerant Discharge __________ psig

Discharge Temp†__________

TEMPERATURE-Heating Mode

Outdoor Air Temperature: __________ DB ____________WB

Return-Air Temperature: __________ DB __________ WB

Cooling Supply Air: __________DB___________WB

PRESSURES-Heating Mode

Refrigerant Suction __________ psig

Suction Line Temp* ___________

Refrigerant Discharge __________ psig

Discharge Temp†__________

____ Verify Refrigerant charge using charging tables

*Measured at suction inlet to compressor

†Measured at liquid line leaving outdoor coil

50zha1si

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.

Book

Tab 6 8

PC 101

Printed in U.S.A.

Catalog No. 50ZHA-1SI

Pg 20

9-05

Replaces: New

Download from Www.Somanuals.com. All Manuals Search And Download.

Blue Rhino Insect Control Equipment SV3100 User Manual
BoomGear MP3 Player MP 700 User Manual
Bosch Power Tools Saw 0601474039 User Manual
Breville Kitchen Grill SG4000 User Manual
Brinkmann Gas Grill Series 4445 User Manual
Brother Fax Machine FAX1570MC User Manual
Canon All in One Printer 2711B054AA User Manual
Canon Printer 4286B008 User Manual
Chamberlain Universal Remote 973TB User Manual
Char Broil Smoker 11201677 User Manual