Bryant R-22 User Manual

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Application Guide and Service Manual

AIR CONDITIONERS AND HEAT PUMPS USING R-22 REFRIGERANT

Cancels: AP01-3, SM01,02-4 SM01,02-5

10-00

NOTE: Read the entire instruction manual before starting the installation.

This symbol → indicates a change since the last issue.

TABLE OF CONTENTS

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

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

INSTALLATION GUIDELINE....................................................2

Residential New Construction..................................................2

Add-On Replacement (Retrofit)...............................................2

Seacoast (For Air Conditioners Only) .....................................2

ACCESSORY DESCRIPTIONS...................................................2

Compressor Crankcase Heater..................................................2

Evaporator Freeze Thermostat..................................................2

Winter Start Control .................................................................2

Compressor Start Assist—PTC................................................2

Compressor Start Assist Capacitor/Relay................................2

Low-Ambient Controller ..........................................................2

MotorMaster™ Control ............................................................2

Low-Ambient Pressure Switch.................................................2

Wind Baffle...............................................................................3

Coastal Filter.............................................................................3

Support Feet..............................................................................3

Liquid-Line Solenoid Valve.....................................................3

Thermostatic-Expansion Valve.................................................3

Isolation Relay..........................................................................3

LOW-AMBIENT GUIDELINE.....................................................3

LONG-LINE GUIDELINE............................................................3

Approved Systems....................................................................3

Interconnecting Tubing Sizing .................................................3

Metering Device Sizing............................................................6

Liquid-Line Solenoid And Tubing Configuration...................7

Charging Information................................................................8

2–Speed Applications ...............................................................8

UNIT IDENTIFICATION .............................................................8

Product Number Stamped on Unit-Rating Plate......................8

Serial Number Identification....................................................9

CABINET.....................................................................................10

Remove Top Cover—Before 1/1/92......................................10

Remove Fan-Motor Assembly—Before 1/1/92.....................10

Information Plate—Reliant Products......................................10

Control-Box Cover—Cube Products......................................10

Remove Top Cover— After 1/1/92 .......................................10

Remove Fan-Motor Assembly—After 1/1/92........................11

ELECTRICAL..............................................................................12

Aluminum Wire......................................................................12

Contactors................................................................................13

Capacitors................................................................................14

Cycle Protector........................................................................15

Crankcase Heater....................................................................16

Time-Delay Relay...................................................................16

Pressure Switches....................................................................17

Defrost Thermostats................................................................18

Defrost-Control Board............................................................18

Fan Motors..............................................................................21

Service Alarm Control Board.................................................21

Outdoor Thermostat(s)............................................................22

Compressor Plug.....................................................................24

Low-Voltage Terminals..........................................................25

RECIPROCATING COMPRESSOR ..........................................25

Mechanical Failures................................................................25

Electrical Failures ...................................................................26

System Cleanup After Burnout..............................................27

Compressor Removal And Replacement ...............................27

COPELAND SCROLL COMPRESSOR ....................................28

Features ...................................................................................28

Troubleshooting ......................................................................28

Discharge Thermostat.............................................................28

Discharge Solenoid Valve......................................................28

MILLENNIUM SCROLL COMPRESSOR................................29

Features ...................................................................................29

Compressor Protection............................................................29

Troubleshooting ......................................................................29

Scroll Compressor, 3–Phase Monitor.....................................29

TWO-SPEED SYSTEM ..............................................................29

Cautions and Warnings...........................................................29

System Functions....................................................................29

Factory Defaults......................................................................33

Major Components..................................................................33

LED Function/Malfunction Lights.........................................34

Troubleshooting ......................................................................34

REFRIGERATION SYSTEM .....................................................35

Refrigeration Cycle.................................................................35

Leak Detection........................................................................35

Brazing....................................................................................37

Service Valves ........................................................................38

Check-Flo-Rater™ (Bypass-Type) Heat Pumps Only...........39

Reversing Valve......................................................................39

Thermostatic-Expansion Valves (TXV).................................40

Thermostatic-Expansion Valve (Bi-Flow TXV)....................41

Coil Removal..........................................................................41

Liquid-Line Strainer (Heat Pumps Only) ..............................41

Accumulator............................................................................43

Contaminant Removal ............................................................43

System Charging.....................................................................43

Checking Charge.....................................................................43

CARE AND MAINTENANCE...................................................45

SAFETY CONSIDERATIONS

Service and repair of these units should be attempted only by trained service technicians familiar with Bryant standard service instructions and training manual.

All equipment should be installed in accordance with accepted practices and unit Installation Instructions, and in compliance with all national and local codes.

Power should be turned off when servicing or repairing electrical components. Extreme caution should be observed when troubleshooting electrical components with power on. Observe all warning notices posted on equipment.

—1—

Refrigeration system contains refrigerant under pressure. Extreme caution should be observed when handling refrigerants. Wear safety glasses and gloves to prevent personal injury. During normal system operation, some components are hot and can cause burns. Rotating fan blades can cause personal injury. Appropriate safety considerations are posted throughout this manual where potentially dangerous techniques are addressed.

It is important to recognize safety information. This is the safety-alert symbol

. When you see this symbol on the unit and in instructions or manuals, be alert to the potential for personal injury.

Understand the signal words DANGER, WARNING, and CAUTION. These words are used with the safety-alert symbol. DANGER identifies the most serious hazards which will result in severe personal injury or death. WARNING signifies hazards which could result in personal injury or death. CAUTION is used to identify unsafe practices which would result in minor personal injury or product and property damage. NOTE is used to highlight suggestions which will result in enhanced installation, reliability, or operation.

WARNING: Improper installation, adjustment, alteration, service, maintenance, or use can cause explosion, fire, electrical shock, or other conditions which may cause personal injury, death, or property damage. Consult a qualified installer, service agency, or your distributor or branch for information or assistance. The qualified installer or agency must use factory-authorized kits or accessories when modifying this product.

INTRODUCTION

This service manual enables a service technician to service, repair, and maintain a family of similar air conditioners and heat pumps. It covers standard single-speed products and 2–speed products only. For variable-speed products, refer to the respective service manuals.

INSTALLATION GUIDELINE

I. RESIDENTIAL NEW CONSTRUCTION

Specifications for this unit in the residential, new-construction market require the outdoor unit, indoor unit, refrigerant-tubing sets, metering device, and filter drier listed in Product Data Sheet (PDS). DO NOT DEVIATE FROM PDS. Consult unit Installation Instructions for detailed information.

II. ADD-ON REPLACEMENT (RETROFIT)

Specifications for this unit in the add-on replacement/retrofit market require change-out of outdoor unit, metering device, and all capillary-tube coils. Change-out of indoor coil is recommended. There can be no deviation.

1. If system is being replaced due to compressor electrical failure, assume acid is in system. If system is being replaced for any other reason, use approved acid test kit to determine acid level. If even low levels of acid are detected, install factory-approved, suction-line filter drier in addition to the factory-supplied, liquid-line filter drier. Remove the suction-line filter drier as soon as possible, with a maximum of 72 hr.

2. Drain oil from low points or traps in suction-line and evaporator if they were not replaced.

3. Change out indoor coil or verify existing coil is listed in the Product Data Sheets.

4. Replace outdoor unit.

5. Install liquid-line filter drier.

6. If suction-line filter drier was installed for system clean up, operate system for 10 hr. Monitor pressure drop across drier. If pressure drop exceeds 3 psig, 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 pressure drop across suction-line filter drier. After 10 hr of run time, remove suction-line filter drier and replace liquid-line filter drier. Never leave

suction-line filter drier in system longer than 72 hr (actual time).

7. Charge system. (See unit information plate.)

III. SEACOAST (FOR AIR CONDITIONERS ONLY)

Installation of these units in seacoast locations requires the use of a coastal filter. (See section on cleaning.)

ACCESSORY DESCRIPTIONS

Refer to Table 1 for an Accessory Usage Guide for Air Conditioners and Heat Pumps. See Model-specific product literature for any kit part number. Refer to the appropriate section below for a description of each accessory and its use.

I. COMPRESSOR CRANKCASE HEATER

An electric heater which mounts to base of compressor to keep lubricant warm during off cycles. Improves compressor lubrication on restart and minimizes chance of refrigerant slugging and oil pumpout. The crankcase heater may or may not include a thermostat control. For units equipped with crankcase heaters, apply power for 24 hr before starting compressor.

II. EVAPORATOR FREEZE THERMOSTAT

An SPST temperature-activated switch stops unit operation when evaporator reaches freeze-up conditions.

III. WINTER START CONTROL

An SPST delay relay which bypasses the low-pressure switch for approximately 3 minutes to permit startup for cooling operation under low-load conditions.

IV. COMPRESSOR START ASSIST—PTC

Solid-state electrical device which gives a ″soft″ boost to the compressor at each start.

V. COMPRESSOR START ASSIST CAPACITOR/RELAY

Start capacitor and start relay gives ″hard″ boost to compressor motor at each start. Required with Liquid-Line Solenoid or hard-shutoff TXV for all equipment.

VI. LOW-AMBIENT CONTROLLER

Low-ambient controller is a cycle-control device activated by a temperature sensor mounted on a header tube of the outdoor coil. It is designed to cycle the outdoor fan motor in order to maintain condensing temperature within normal operating limits (approximately 100°F high, and 60°F low). The control will maintain working head pressure at low-ambient temperatures down to 0°F when properly installed.

VII. MOTORMASTER™ CONTROL

A fan speed-control device activated by a temperature sensor. It is designed to control condenser fan-motor speed in response to the saturated, condensing temperature during operation in cooling mode only. For outdoor temperature down to -20°F, it maintains condensing temperature at 100°F±10°F. Requires a ball-bearing fan motor.

VIII. LOW-AMBIENT PRESSURE SWITCH

A long-life pressure switch which is mounted to outdoor unit service valve. It is designed to cycle the outdoor fan motor in response to condenser pressure in cooling mode in order to maintain head pressure within normal operating limits (approximately 100 psig to 225 psig). The control will maintain working head pressure at low-ambient temperatures down to 0°F when properly installed.

—2—

TABLE 1—REQUIRED FIELD-INSTALLED ACCESSORIES FOR AIR CONDITIONERS AND HEAT PUMPS

REQUIRED FOR

ACCESSORY

Crankcase Heater Yes Yes No

Evaporator Freeze Thermostat Yes No No

Winter Start Control Yes† No No

Accumulator No No No

Compressor Start Assist

Capacitor and Relay

Low Ambient Controller,

MotorMaster™ Control,

Low-Ambient Pressure Switch

Liquid-Line Solenoid Valve

Ball-Bearing Fan Motor Yes‡ No No

*For tubing line sets between 50 and 175 ft, refer to Residential Split-System Long-Line Application Guideline. †Only when low-pressure switch is used. ‡Required for Low-Ambient Controller (full modulation feature) and MotorMaster™ control only. ** Required on Heat Pumps only.

Wind Baffle See Low-Ambient Instructions No No Coastal Filter No No Yes Support Feet Recommended No Recommended

Hard-Shutoff TXV

Isolation Relay Yes** No No

LOW-AMBIENT

APPLICATIONS

(BELOW 55°F)

Yes Yes No

Yes No No

REQUIRED FOR

LONG-LINE

APPLICATIONS*

(OVER 50 FT)

See Long-Line

Application

Guideline

REQUIRED FOR

SEA COAST

APPLICATIONS

(WITHIN 2 MILES)

IX. WIND BAFFLE

A field-fabricated sheet-metal cover used to stop prevailing winds or where outdoor ambient temperature is less than 55°F during unit operation of cooling mode.

X. COASTAL FILTER

A mesh screen inserted under top cover and inside base pan to protect condenser coil from salt damage without restricting airflow.

XI. SUPPORT FEET

Four adhesive plastic feet which raise unit 4 in. above mounting pad. This allows sand, dirt, and other debris to be flushed from unit base; minimizes corrosion.

XII. LIQUID-LINE SOLENOID VALVE

An electrically operated shutoff valve to be installed at outdoor or indoor unit (depending on tubing configuration) which stops and starts refrigerant liquid flow in response to compressor operation. Maintains a column of refrigerant liquid ready for action at next compressor-operation cycle and prevents liquid migration during the off cycle.

XIII. THERMOSTATIC-EXPANSION VALVE

A modulating flow-control device which meters refrigerant flow rate into the evaporator in response to the superheat of the refrigerant gas leaving the evaporator. Only use factory-specified TXV’s.

XIV. ISOLATION RELAY

A DPDT relay which switches the low-ambient controller out of the outdoor fan-motor circuit when the heat pump switches to heating mode.

LOW-AMBIENT GUIDELINE

The minimum operating temperature for these units in cooling mode is 55°F outdoor ambient without additional accessories. This equipment may be operated in cooling mode at ambient temperatures below 55°F when the accessories listed in Table 1 are installed. Wind baffles are required when operating in cooling mode at ambients below 55°F. Refer to Fig. 1 or 2 and Table 2 or 3 for wind baffle construction details.

LONG-LINE GUIDELINE

This Long-Line Application Guideline applies to all Bryant residential air conditioner and heat pump split systems that have a nominal capacity of 18,000 to 60,000 Btuh. This guideline provides required system changes and accessories necessary for any residential product having piping requirements greater than 50 ft or installations where indoor unit is located above outdoor unit. This guideline is intended to cover applications outside the standard Installation Instructions. This guideline is for standard, single-speed products. For applications involving 2-speed products, refer to Section VI first.

NOTE: The presale literature for outdoor unit must be referred to in conjunction with this guideline.

I. APPROVED SYSTEMS

Any residential indoor/outdoor unit combination listed in the outdoor unit presale literature is an approved system, EXCEPT the following:

• Indoor coils with capillary-metering devices

• All equipment less than nominal 18,000 Btuh

• All 1/4-in. and 5/16–in. liquid-line applications

• Any indoor furnace coil/fan coil not listed in outdoor unit

presale literature

• Any application which has interconnecting tubing with an equivalent length greater than 175 ft

II. INTERCONNECTING TUBING SIZING

Table 4 lists recommended interconnecting vapor-line diameters for equivalent total-line lengths. All residential split systems installed in long-line applications must use only 3/8-in. liquid lines. Equivalent line length equals the linear length (measured) of interconnecting vapor tubing plus losses due to elbows. (See Table 5 and Fig. 3.) Liquid lines larger than 3/8-in. OD greatly increase charge quantity of the system. Excessive charge increases risk of migration and compressor damage. Table 4 provides the estimated percentage of nominal cooling-capacity losses based on the standard, required vapor line size versus what is selected for the long-line application. Since the vapor line is the discharge line in heating mode, losses are minimal.

—3—

/4″ x 3/8″ (5.56 x 9.53) SLOT

4 REQ'D

5/16″

(151.5)

/8″ (3.45) DIA HOLE

2 REQ'D

/4″ (5.56) DIA HOLE 2 REQ'D

/8″

(9.6)

/2″

(12.7)

/2″

(12.7)

TYP

/16″

(11.6)

SUPPORT

MAT'L: 18 GA STEEL

/8″ (3.45) DIA HOLE

1 REQ'D

/4″ (5.56) DIA HOLE

/16″

(11.6)

3 REQ'D

6″

(152.4)

/4″

(6.3)

BAFFLE

/4″ x 2″

(5.56 x 50.8) SLOT

/8″ (9.6)

MAT'L: 20 GA STEEL

SCREW 10 REQ'D

SUPPORT

4 REQ'D

OUTDOOR

BAFFLE

2 REQ'D

UNIT

BAFFLE ASSEMBLY

Fig. 1—Wind Baffle Construction for Reliant Units

—4—

A95445

Calculate the linear length of vapor tube required, adding any losses for the total number of elbows for application. (See Table

5.) Using this equivalent length, select desired vapor-line size from Table 4. Subtract the nominal percentage loss from outdoor-unit

All standard accessory-tubing kits are supplied with 3/8-in. insulation on vapor line. For minimal capacity loss in long-line application, 1/2-in. insulation should be specified.

presale-literature Detailed Cooling Capacities data for the given indoor/outdoor combination. Reference all notes of Table 4.

NOTE: When specifying vapor-line insulation, be aware of the following standard practice:

TABLE 2—WIND BAFFLE DIMENSIONS FOR RELIANT UNITS WITH AEROQUIET-SYSTEM TOP (IN.)

UNIT SIZE AA UNIT HEIGHT A B C D E F G H J K L

23-13/16 17-1/4 24-5/16 10-1/4 19-3/4 20-1/2 34-1/2 19-5/8 20-3/8 19-5/8 0 0

Small 26-3/16

Medium 33

Large 42-1/16

27-13/16 17-1/4 24-5/16 10-1/4 23-3/4 24-1/2 34-1/2 23-5/8 24-3/8 23-5/8 0 11-7/8 33-13/16 17-1/4 24-5/16 10-1/4 29-3/4 30-1/2 34-1/2 29-5/8 30-3/8 29-5/8 0 14-7/8 27-13/16 21 30-5/8 10-1/4 23-3/4 24-1/2 42 23-5/8 24-3/8 23-5/8 17-1/8 11-7/8 33-13/16 21 30-5/8 10-1/4 29-3/4 30-1/2 42 29-5/8 30-3/8 29-5/8 17-1/8 14-7/8 39-13/16 21 30-5/8 10-1/4 35-3/4 36-1/2 42 35-5/8 36-3/8 35-5/8 17-1/8 17-7/8 33-13/16 25-5/16 39-3/4 10-1/4 29-3/4 30-1/2 50-9/16 29-5/8 30-3/8 29-5/8 21-11/16 14-7/8 39-13/16 25-5/16 39-3/4 10-1/4 35-3/4 36-1/2 50-9/16 35-5/8 36-3/8 35-5/8 21-11/16 17-7/8

/64″ (205.3)

TYP

/8″

(199.9)

/4″

(6.4)

/4″ (5.56) DIA

2 REQ'D

/4″ x 3/8″ (5.56 x 9.53) SLOT

6 REQ'D

/64″ (105.2)

45°

TYP

/4″

(6.4)

(200.0)

(12.7)

/64″

(128.0)

/64″

(52.6)

⁄

(124.2) TYP

/2″ (12.7)

TYP

/64″ (9.2)

/8″

/2″

/64″ (10.0)

/2″

(63.5)

/32″ (42.1)

/64″

(9.2)

″

/16″

(4.6)

BAFFLE - LEFT

MAT'L: 20 GA STEEL

/8″ (3.45) DIA

2 REQ'D

SUPPORT

MAT'L: 18 GA STEEL

/2″

(63.5)

(128.0)

⁄64″ (10.0)

/4″ (5.56) DIA

2 REQ'D

/64″

(5.4)

TYP

/32″ (42.1)

LEFT SIDE

/2″

(12.7)

/32″ (200.8)

TYP

BAFFLE - RIGHT

MAT'L: 20 GA STEEL

/4″ x 3/8″ (5.56 x 9.53) SLOT

6 REQ'D

/4″ (5.56) DIA

4 REQ'D

OUTDOOR

UNIT

RIGHT SIDE

SCREW 14 REQ'D

SUPPORT 3 REQ'D

/8″ (3.45) DIA.

4 REQ'D

BAFFLE ASSEMBLY

A95446

Fig. 2—Wind Baffle Construction for Cube Units

—5—

TABLE 3—WIND BAFFLE DIMENSIONS FOR CUBE UNITS (IN.)

UNIT SIZE AA UNIT HEIGHT A B C D E F G H J

21-15/16 19-7/8 13-3/4 28-1/8 10-11/16 20-1/4 11-11/16 3-13/16 19-13/16 17-13/16 23-15/16 21-7/8 13-3/4 28-1/8 10-11/16 20-1/4 11-11/16 3-13/16 21-13/16 19-13/16 25-15/16 23-7/8 13-3/4 28-1/8 10-11/16 20-1/4 11-11/16 3-13/16 23-13/16 21-13/16

Small 18

Medium 22-1/2

Large 30

27-15/16 25-7/8 13-3/4 28-1/8 10-11/16 20-1/4 11-11/16 3-13/16 25-13/16 23-13/16 29-15/16 27-7/8 13-3/4 28-1/8 10-11/16 20-1/4 11-11/16 3-13/16 27-13/16 25-13/16 31-15/16 29-7/8 13-3/4 28-1/8 10-11/16 20-1/4 11-11/16 3-13/16 29-13/16 27-13/16 33-15/16 31-7/8 13-3/4 28-1/8 10-11/16 20-1/4 11-11/16 3-13/16 31-13/16 29-13/16 21-15/16 19-7/8 18-5/16 32-5/8 10-11/16 24-3/4 16-3/16 8-1/4 19-13/16 17-13/16 23-15/16 21-7/8 18-5/16 32-5/8 10-11/16 24-3/4 16-3/16 8-1/4 21-13/16 19-13/16 25-15/16 23-7/8 18-5/16 32-5/8 10-11/16 24-3/4 16-3/16 8-1/4 23-13/16 21-13/16 27-15/16 25-7/8 18-5/16 32-5/8 10-11/16 24-3/4 16-3/16 8-1/4 25-13/16 23-13/16 29-15/16 27-7/8 18-5/16 32-5/8 10-11/16 24-3/4 16-3/16 8-1/4 27-13/16 25-13/16 31-15/16 29-7/8 18-5/16 32-5/8 10-11/16 24-3/4 16-3/16 8-1/4 29-13/16 27-13/16 33-15/16 31-7/8 18-5/16 32-5/8 10-11/16 24-3/4 16-3/16 8-1/4 31-13/16 29-13/16 35-15/16 33-7/8 18-5/16 32-5/8 10-11/16 24-3/4 16-3/16 8-1/4 33-13/16 31-13/16 37-15/16 35-7/8 18-5/16 32-5/8 10-11/16 24-3/4 16-3/16 8-1/4 35-13/16 33-13/16 25-15/16 23-7/8 25-3/4 40-1/8 10-11/16 32-1/4 23-11/16 15-13/16 23-13/16 21-13/16 27-15/16 25-7/8 25-3/4 40-1/8 10-11/16 32-1/4 23-11/16 15-13/16 25-13/16 23-13/16 29-15/16 27-7/8 25-3/4 40-1/8 10-11/16 32-1/4 23-11/16 15-13/16 27-13/16 25-13/16 31-15/16 29-7/8 25-3/4 40-1/8 10-11/16 32-1/4 23-11/16 15-13/16 29-13/16 27-13/16 33-15/16 31-7/8 25-3/4 40-1/8 10-11/16 32-1/4 23-11/16 15-13/16 31-13/16 29-13/16 35-15/16 33-7/8 25-3/4 40-1/8 10-11/16 32-1/4 23-11/16 15-13/16 33-13/16 31-13/16 37-15/16 35-7/8 25-3/4 40-1/8 10-11/16 32-1/4 23-11/16 15-13/16 35-13/16 33-13/16 39-15/16 37-7/8 25-3/4 40-1/8 10-11/16 32-1/4 23-11/16 15-13/16 37-13/16 35-13/16

TABLE 4—ESTIMATED PERCENTAGE OF NOMINAL COOLING-CAPACITY LOSSES*

UNIT

NOMINAL

SIZE

(BTUH)

18,000

24,000

30,000

36,000

42,000

48,000

60,000

*The estimated percentage of cooling capacity that must be subtracted from the Detailed Cooling Capacities data specified in outdoor unit-presale literature for any given indoor/outdoor combination. †Vapor-line diameter that may be selected for a long-line application. If smaller vapor lines are selected but not specified within the table, large capacity losses will occur and defrost capabilities will be reduced. If larger vapor lines are selected but not specified within the table, refrigerant oil return will be impaired due to velocity losses. N/R—Not recommended due to excessive loss of capacity.

For reference only, the close cell insulation material specified for accessory tubing kits is a compound of vinyl, neoprene, or nitrile blends of these polymers. Performance requirements include thermal range of 0° Fto200°F (-17.8° Cto93° C) and a maximum thermal conductivity of 0.28.

NOTE: Special consideration must be given to isolating interconnecting tubing from building structure. Isolate tubing so that vibration or noise is not transmitted into structure.

III. METERING DEVICE SIZING

The metering device for a long-line application must be flexible enough to compensate for frictional losses due to long refrigerant

LONG-LINE

VAPOR-LINE

DIAMETER

(IN.)†

5/8 5 7 9 12 12 14 3/4 1 3 4 5 5 7 5/8 6 9 13 16 19 22 3/4 0 1 1 2 3 4 5/8 6 8 10 13 15 17 3/4 2 3 4 5 6 7 3/4 7 10 14 17 21 N/R 7/8 2 4 6 8 10 11 3/4 7 10 13 17 20 23 7/8 3 4 6 7 8 10

1-1/8 0 0 1 1 2 2

3/4 10 14 18 22 N/R N/R 7/8 4 6 7 9 11 13

1-1/8 0 0 1 1 2 2

7/8 7 9 11 14 16 19

1-1/8 1 2 2 3 3 4

50 75 100 125 150 175

EQUIVALENT LINE LENGTH (FT)

lines and installed system design (indoor coil above or below outdoor unit.) The piston or TXV provides such flexibility.

The piston should be changed for both indoor coil and outdoor heat pump unit, depending on system configuration and line length. Tables 6 and 7 provide necessary changes for a given application.

Use Tables 6 and 7 when selecting correct piston size. Outdoorunit presale literature must be consulted to determine metering devices specified for standard applications. After determining standard application piston size(s), refer to Tables 6 and 7 as they relate to system design (outdoor unit above or below indoor unit) per equivalent length of tubing.

—6—

90° STD

90° LONG RAD

EXAMPLE: An 042 size heat pump is 75 ft above an 042 size fan coil. The 042 size heat-pump presale literature specifies a size 80 indoor piston and size 63 outdoor piston. To establish correct indoor piston size for a 75 ft vertical

separation, refer to Table 6. For a 75 ft equivalent line length, the piston change is -5. Therefore subtract 5 from the original indoor piston size of 80: 80 – 5=75 Table 8 provides common piston sizes. In this instance, 75 is not listed, therefore round DOWN to next piston size, which would be 74. To establish correct outdoor piston size for a 75 ft vertical separation, refer to Table 7. For a 75 ft equivalent line length, the piston change is +4. Therefore add 4 to the original outdoor piston size of 63: 63+4=67 Since 67 is listed in Table 8, that is the piston which should be used. If a 67 size piston were not listed, it would be necessary to round UP to next piston size.

TXVs may be used instead of pistons for indoor-metering devices. Some fan coils are equipped with a hard-shutoff, bi-flow TXV standard, and no change is required. When sizing an accessory TXV for long-line applications, TXV should be the same nominal tonnage as outdoor unit. Refer to presale literature for kit part numbers.

45° STD

A92498

Fig. 3—Tube Bend Losses

TABLE 5—FITTING LOSSES IN EQUIVALENT FT

TUBE SIZE OD

(IN.)

5/8 1.6 1.0 0.8 3/4 1.8 1.2 0.9 7/8 2.0 1.4 1.0

1-1/8 2.6 1.7 1.3

REFERENCE DIAGRAM IN FIG. 1

ABC

NOTE: If total equivalent horizontal length is 100 ft or longer, both indoor and outdoor pistons must be increased 1 full piston size, in addition to changes required by Tables 6 and 7.

After finding appropriate change in piston size, add or subtract the change from original piston number. If piston size is decreased, round new piston number down to nearest common piston number found in Table 8. If piston size is increased, round new piston number up to nearest common piston number found in Table 8.

TABLE 6—CALCULATION OF INDOOR PISTON NO.

OUTDOOR UNIT ABOVE INDOOR

FT PISTON CHANGE

0-25 0 26-50 -3 51-75 -5

76-100 -7 101-125 -9 126-150 -10

OUTDOOR UNIT BELOW INDOOR

FT PISTON CHANGE

0-25 0

26-50 +4

TABLE 7—CALCULATION OF OUTDOOR PISTON NO.

OUTDOOR UNIT ABOVE INDOOR

FT PISTON CHANGE

0-50 0

51-75 +4

76-100 +6 101-125 +8 126-150 +10

OUTDOOR UNIT BELOW INDOOR

FT PISTON CHANGE

0-50 0

IV. LIQUID-LINE SOLENOID AND TUBING CONFIGURATION

There are 2 types of liquid-line solenoids: 1 for single-flow applications and the other for bi-flow applications. The purpose of having 2 solenoids is to minimize the valve internal-pressure drop in accordance with refrigerant flow direction and liquid migration to the compressor. The bi-flow solenoid is designed to have minimal refrigerant-pressure drop in either flow direction, which makes it suitable for heat pump usage. Refer to Table 9 for liquid-line solenoid kit part numbers.

—7—

TABLE 8—COMMON PISTON SIZES

CHECK-FLO-

RATER™

— 32 65 65 — 33 67 67

35 35 — 68

— 36 70 70 — 37 — 71

38 38 73 73

— 39 — 74

40 40 76 76

— 41 78 78

42 42 80 80

— 43 — 81 — 45 82 82

46 — 84 84

— 47 86 86

49 49 88 88 51 51 — 89 52 52 90 90

— 53 — 92

55 55 93 93 57 57 96 96 59 59 98 98 61 61 101 101

— 62 104 104

63 63 109 —

CHATLEFF

CHECK-FLO-

RATER™

CHATLEFF

NOTE: When installing a liquid-line solenoid, the system may

require a minimum 60va low-voltage transformer. Each type of solenoid has an indicator flow arrow stamped on the

valve body. When solenoid is closed (not energized) and pressure is applied in direction of flow arrow, complete shutoff occurs. If pressure is applied against direction of flow arrow, leakage through valve occurs. When determining proper installation of valve within liquid line, 2 considerations must be made:

1. Direction of flow arrow

2. Where solenoid is installed in system.

TXVs can only be substituted for liquid-line solenoids in singleflow air conditioning systems. Bi-flow TXVs allow liquid migration to coldest point during off cycles, which could allow liquid into compressor.

Fig. 4 through 7 detail proper installation of liquid-line solenoid and provide applications where TXVs may be substituted. Reference all notes of the appropriate figures.

TABLE 9—LIQUID-LINE SOLENOID KIT PART NUMBERS

TYPE OF VALVE PART NO.

Single Flow KAALS0101LLS

Bi-Flow KHALS0401LLS

V. CHARGING INFORMATION

Weigh in appropriate refrigerant charge, then use the standard practices of superheat-charging method for piston applications and subcooling-charging method for TXV applications to confirm correct charge. The standard charging methods can be found on outdoor unit-information plate, in unit Installation Instructions, or in the Service Manual. Since total system charge is increased for long-line applications, it may be necessary to calculate the additional refrigerant charge. Since long-line applications only involve 3/8-in. liquid lines, the additional refrigerant charge required is 0.6 oz of Refrigerant 22 (R-22) per ft of 3/8-in. liquid line over 15 ft.

EXAMPLE: To calculate additional charge required for a 25–ft line set: 25 ft – 15 ft = 10 ft X 0.6 oz/ft=6ozofadditional charge

The rating-plate charge of a given outdoor unit is for a standard application of 15 ft of interconnecting tubing. The rating-plate charge can be found on outdoor unit-rating plate or in outdoor unit-presale literature. Long-line applications do not require additional oil charge.

VI. 2–SPEED APPLICATIONS

Outdoor units may be connected to indoor section using accessory tubing package or field-supplied refrigerant grade tubing of correct size and condition. In long–line applications, 2–speed units are handled basically the same way as the single-speed units. There are 2 major differences:

1. For tubing up to 100 ft: Liquid tube diameters and refrigerant connection diameters for all sizes are 3/8 in. Vapor tube diameter for the 036 and 048 is 7/8 in.; 060 is 1–1/8 in. Vapor refrigerant connection diameter for all sizes is 7/8 in. DO NOT INSTALL EQUIVALENT INTERCONNECTING TUBING LENGTHS GREATER THAN 100 FT.

2. Do not increase or decrease tubing sizes.

For other applications see the previous sections under Long-Line Guidelines.

UNIT IDENTIFICATION

I. PRODUCT NUMBER STAMPED ON UNIT-RATING PLATE

The unit product number has 16 positions containing groups of numbers and letters that indicate specific information about the unit. Listed below is the breakdown of the 16 positions. Positions 1, 2, and 3—Product Series Example: A 500–series number indicates a split-system condensing unit and a 600–series number indicates a split-system heat pump. Position 4—Model Letters New models are introduced with the letter A, and subsequent model changes are identified by changing to the next letter, as B, then C, and so forth. Position 5—Electrical Characteristics Example: J—208–230, 1 Phase, 60 Hertz N—208/230, 208/240, 1 Phase, 60 Hertz P—208/230, 208/240, 3 Phase, 60 Hertz E—460, 3 Phase, 60 Hertz Q—220, 3 Phase, 50 Hertz S—220/240, 1 Phase, 50 Hertz Z—380/415, 3 Phase, 50 Hertz Position 6—Fuel and Controls Not applicable on condensing units or heat pumps, so the letter ’X’ is used to signify ’none.’ Positions 7, 8, and 9—Nominal Cooling Capacity (in thousands Btuh) Example: 036 = 36,000 Btuh or 3–ton capacity. Positions 10, 11, and 12—Not applicable on condensing units or heat pumps, so the number ’zero’ is used to signify ’none.’ Position 13—Brand Name Example: A—Common unit —U.S.A. Only Position 14—Unit Series New units are introduced with the letter A, and subsequent major component variations, such as in compressor, fan motor, coil circuitor size, etc., are identified by changing to the next letter, as B, then C, and so forth.

—8—

Positions 15 and 16—Product Variations Example: AA—Standard unit Other letters—For product variations from standard

II. SERIAL NUMBER IDENTIFICATION

The unit serial number has 10 positions containing groups of numbers and a letter that indicate specific information about the unit. Listed below is the breakdown of the 10 positions. Positions 1 and 2—Week of Manufacture Example: 01—First week of a year

175' MAX.

GROUND LEVEL

52—Last week of a year Positions 3 and 4—Year of Manufacture Example: 94—1994 Position 5—Manufacturing Site Example: A–Indianapolis E–Collierville Positions 6 through 10—Serial Number

BASEMENT

Fig. 4—Application with Air Conditioner Installed in a Horizontal Configuration

175' MAX.

GROUND LEVEL

A90074

BASEMENT

Fig. 5—Application with Heat Pump Installed in a Horizontal Configuration

—9—

A90075

HEAT PUMP ONLY

GROUND LEVEL

Fig. 6—Application with Air Conditioner or Heat Pump Installed with Indoor Unit Above Outdoor Unit

CABINET

Certain maintenance routines and repairs require removal of cabinet panels. There are 4 basic cabinet designs for air conditioners and heat pumps. (See Fig. 8.) The horizontal discharge unit will be discussed in a separate section of this manual. Note that separate sections apply according to date of manufacture.

I. REMOVE TOP COVER—BEFORE 1/1/92 NOTE: This section applies to all Reliant products made prior to

January 1, 1992.

1. Turn off all power to outdoor and indoor units.

2. Remove screws holding top cover to coil grille and corner posts.

3. Remove access panel.

4. Remove information plate.

5. Disconnect fan motor wires, cut wire ties, and remove wire ties from control box. Refer to unit-wiring label.

6. Lift top cover from unit.

7. Reverse sequence for reassembly.

II. REMOVE FAN-MOTOR ASSEMBLY—BEFORE 1/1/92 NOTE: This section applies to all Reliant products made prior to

January 1, 1992.

1. Perform items 1 through 6 above.

2. Remove nuts holding fan-motor top cover.

3. Remove motor and fan blade assembly.

4. Reverse sequence for reassembly.

5. Prior to applying power, check that fan rotates freely.

TRAP

50' MAX.

A90076

III. INFORMATION PLATE—RELIANT PRODUCTS

The information plate is secured to the front of the control box and provides a cover for it. (See Fig. 9.) This plate also provides a surface to attach the wiring schematic, superheat-charging tables with instructions, and warning labels. The plate has 2 tabs on the top edge that are bent down at slightly more than 90°. When the information plate is removed, these tabs can be inserted into 2 mating slots in the bottom-front edge of the control box, and the plate will hang down, forming a lower front panel. (See Fig. 10.) This is convenient where access to the controls is required while the unit is operating. The information plate on the small size casing completely covers the opening below the control box. On larger models, the information plate may not cover the entire opening. In this instance, the top cover can be removed and placed on its side to cover the additional space.

IV. CONTROL-BOX COVER—CUBE PRODUCTS

This panel contains much of the same information as the information plate mentioned previously, but is designed only to cover the control box.

V. REMOVE TOP COVER— AFTER 1/1/92 NOTE: The section applies to all Reliant Products made after

January 1, 1992.

1. Turn off all power to outdoor and indoor units.

2. Remove 5 screws holding top cover to coil grille and coil tube sheet.

3. Remove 2 screws holding control-box cover.

4. Remove 2 screws holding information plate.

5. Disconnect fan motor wires, cut any wire ties, and move wires out of control box and through tube clamp on back of control box.

—10—

150' MAX.

HEAT PUMP ONLY

Fig. 7—Application with Air Conditioner or Heat Pump Installed Above Indoor Unit

6. Lift top cover from unit.

7. Reverse sequence for reassembly.

VI. REMOVE FAN-MOTOR ASSEMBLY—AFTER 1/1/92 NOTE: This section applies to all Reliant products made after

January 1, 1992

1. Perform items 1, 3, 4, and 5 above. (Note item 2 is not required.)

2. Remove 4 screws holding wire basket to top cover.

3. Lift wire basket from unit.

4. Remove nuts holding fan motor to wire basket.

5. Remove motor and fan blade assembly.

6. Pull wires through wire raceway to change motor.

7. Reverse sequence for reassembly.

8. Prior to applying power, check that fan rotates freely.

A90077

—11—

Fig. 8—Basic Cabinet Designs

A94003

ELECTRICAL

WARNING: Exercise extreme caution when working on

any electrical components. Shut off all power to system prior to troubleshooting. Some troubleshooting techniques require power to remain on. In these instances, exercise extreme caution to avoid danger of electrical shock. ONLY TRAINED SERVICE PERSONNEL SHOULD PERFORM ELECTRICAL TROUBLESHOOTING.

Troubleshooting charts for air conditioning and heat pump units are provided in the back of this manual. They enable the service technician to use a systematic approach to locate the cause of a problem and correct system malfunctions.

I. ALUMINUM WIRE

CAUTION: Aluminum wire may be used in the branch

circuit (such as the circuit between the main and unit disconnect), but only copper wire may be used between the unit disconnect and the unit on Bryant systems.

Whenever aluminum wire is used in the branch-circuit wiring with this unit, adhere to the following recommendations. Connections must be made in accordance with the National Electrical Code (NEC), using connectors approved for aluminum wire. The connectors must be UL-approved (marked Al/Cu with the UL symbol) for the application and wire size. The wire size selected must have a current capacity not less than that of the copper wire specified and must not create a voltage drop between the service panel and the unit in excess of 2 percent of the unit-rated voltage. To prepare the wire before installing the connector, all aluminum wire must be ″brush scratched″ and coated with a corrosion inhibiter such as Pentrox A. When it is suspected that the

—12—

SEFL JOSDJ

SEFL JOSDJ SEFL JOSDJ

SEFL JOSDJ

SEFL JOSDJ PAASFLDLKREW

SEFL JOSDJ

SEFL JOSDJ ATC

SEFL JOSDJ

SEFL JOSDJ UTUHD

SEFL JOSDJ

SEFL JOSDJC MD

SEFL JOSDJ

SEFL JOSDJHR ITYALK

SEFL JOSDJ

A88411

Fig. 9—Information Plate

connection will be exposed to moisture, it is very important to cover the entire connection completely to prevent an electrochemical action that will cause the connection to fail very quickly. Do not reduce the effective size of wire, such as cutting off strands so that the wire will fit a connector. Proper size connectors should be used. Check all factory and field electrical connections for tightness. This should also be done after the unit has reached operating temperatures, especially if aluminum conductors are used.

II. CONTACTORS NOTE: The section applies to single-speed models only.

The contactor provides a means of applying power to unit using low voltage (24v) from transformer in order to power the contactor coil. (See Fig. 11.) Depending on unit model, you may encounter single-, double-, or triple-pole contactors to break power. One side of the line may be electrically energized, so exercise extreme caution when troubleshooting.

The contactor coil for residential air-conditioning units and heat pumps is powered by 24vac. If contactor does not operate:

1. With power off, check whether contacts are free to move. Check for severe burning or arcing on contact points.

2. With power off, use ohmmeter to check for continuity of coil. Disconnect leads before checking. A low-resistance reading is normal. Do not look for a specific value, as different part numbers have different resistance values.

3. Reconnect leads and apply low-voltage power to contactor coil. This may be done by leaving high-voltage power to outdoor unit off, and turning thermostat to heat or cool. Check voltage at coil with voltmeter. Reading should be between 20v and 30v. Contactor should pull in if voltage is correct and coil is good. If contactor does not pull in, change contactor.

4. With high-voltage power off and contacts pulled in, check for continuity across contacts with ohmmeter. A very low or zero resistance should be read. Higher readings could indicate burned or pitted contacts which may cause future failures.

SEFL JOSDJ SEFL JOSDJ SEFL JOSDJ

SEFL JOSDJ

SEFL JOSDJ PAASFLDLKREW

SEFL JOSDJ

SEFL JOSDJ ATC

SEFL JOSDJ

SEFL JOSDJ UTUHD

SEFL JOSDJ

SEFL JOSDJC MD

SEFL JOSDJ

SEFL JOSDJHR ITYALK

SEFL JOSDJ

A88412

Fig. 10—Information Plate Removed/Installed Below Control Box

—13—

SEFL JOSDJ SEFL JOSDJ SEFL JOSDJ

SEFL JOSDJ

SEFL JOSDJ SEFL JOSDJ SEFL JOSDJ SEFL JOSDJ

SEFL JOSDJ PAASFLDLKREW

SEFL JOSDJ ATC

SEFL JOSDJ UTUHD

SEFL JOSDJC MD

SEFL JOSDJHR ITYALK

SEFL JOSDJ

A88413

A88350

Fig. 11—Contactor

III. CAPACITORS

CAUTION: Capacitors can store electrical energy when

power is off. Electrical shock can result if you touch the capacitor terminals and discharge the stored energy. Exercise extreme caution when working near capacitors. With power off, discharge stored energy by shorting across the capacitor terminals with a 15,000-ohm, 2-watt resistor.

NOTE: If bleed resistor is wired across start capacitor, it must be disconnected to avoid erroneous readings when ohmmeter is applied across capacitor. (See Fig. 12.)

A91455

Fig. 12—Capacitors

Use the following formula to calculate capacitance: Capacitance (mfd) = (2650 X amps) divided by (volts)

3. Remove any capacitor that shows signs of bulging, dents, or leaking. Do not apply power to a defective capacitor as it may explode.

START CAPACITORS AND PTC DEVICES Sometimes under adverse conditions, a standard run capacitor in a

system is inadequate to start compressor. In these instances, a start-assist device is used to provide an extra starting boost to compressor motor. The first device is called a positive-temperature coefficient (PTC) or thermistor. (See Fig. 13.) It is a resistor wired in parallel with the run capacitor. As current flows through the PTC at start-up, it heats up. As it heats up, its resistance increases greatly until it effectively lowers the current through it to an extremely low value. This, in effect, removes it from the circuit.

CAUTION: Always check capacitors with power off. Attempting to troubleshoot a capacitor with power on can be dangerous. Defective capacitors may explode when power is applied. Insulating fluid inside is combustible and may ignite, causing burns.

Capacitors are used as a phase-shifting device to aid in starting certain single-phase motors. Check capacitors as follows.

1. After power is off, discharge capacitors as outlined above. Disconnect capacitor from circuit. Put ohmmeter on R X 10k scale. Using ohmmeter, check each terminal to ground (use capacitor case). Discard any capacitor which measures 1/2–scale deflection or less. Place ohmmeter leads across capacitor and place on R X 10k scale. Meter should jump to a low-resistance value and slowly climb to higher value. Failure of meter to do this indicates an open capacitor. If resistance stays at zero or a low value, capacitor is internally shorted.

2. Capacitance testers are available which read value of capacitor. If value is not within ± 10 percent value stated on capacitor, it should be changed. If capacitor is not open or shorted, the capacitance value is calculated by measuring voltage across capacitor and current it draws.

WARNING: Exercise extreme caution when taking readings while power is on. Electrical shock can cause personal injury or death.

20-36

OHMS

BLUE

20 OHM

(BLUE COLOR)

12.5-22.5

12.5 OHM

(BEIGE COLOR)

OHMS

25-45

OHMS

25 OHM

(BLUE COLOR)

A88414

Fig. 13—PTC Devices

After system shutdown, resistor cools and resistance value returns to normal until next time system starts. If indoor coil does not have a bleed-type expansion device, it may be necessary to remove start thermistor and replace with accessory start capacitor and relay. Consult pre-sale literature for application of start kits. Thermistor device is adequate for most conditions; however, in systems where off-cycle is short, device cannot cool fully and becomes less effective as a start device. It is an easy device to troubleshoot.

1. Shut off all power to system.

2. Check thermistor with ohmmeter as described below.

3. Shut off all power to unit.

—14—

4. Remove PTC from unit. Wait at least 10 minutes for PTC to cool to ambient temperature.

5. Measure resistance of PTC with ohmmeter as shown in Fig.13.

The cold resistance (RT) of any PTC device should be approximately 100 – 180 percent of device ohm rating.

12.5–ohm PTC = 12.5–22.5 ohm resistance — beige color 25–ohm PTC = 25–45 ohm resistance — blue color 20–ohm PTC = 20–36 ohm resistance — blue color

If PTC resistance is appreciably less than rating or more than 200 percent higher than rating, device is defective.

If thermistor is good and compressor does not start:

1. Disconnect thermistor from starting circuit.

2. Give compressor a temporary capacitance boost (see next section).

3. Run compressor for 10 minutes, shut off, and allow system pressure to equalize.

4. Reconnect start thermistor.

5. Try restarting compressor without boost capacitor. If after 2 attempts compressor does not start, remove thermistor. Add an accessory start-capacitor relay package.

TEMPORARY CAPACITANCE BOOST

WARNING: Do not under any circumstances attach a temporary boost capacitor directly to the compressor terminals. Serious personal injury can result. Exercise extreme caution with this procedure when high-voltage power is on.

There are times when a temporary capacitance boost is needed to get compressor started. (See Fig. 14.) If compressor motor does not start, it may be due to low-line voltage, improper pressure equalization, weak run capacitor, or a seized compressor. Check each possibility and attempt capacitance boost before adding auxiliary start capacitor and relay.

220-V FROM UNIT CONTACTOR

COMP. RUN CAPACITOR

START (BOOST) CAPACITOR

A88349

Fig. 14—Capacitance Boosting

1. Turn off all power to unit. There may be more than one power source to condensing unit.

NOTE: If a PTC is already installed, remove it from the system by pulling PTC wires from H and C terminals on run capacitor.

2. Check compressor for ground or open windings. If winding’s resistance is within manufacturer’s recommendations, proceed. (See Reciprocating Compressor Section IIElectrical Failures for proper compressor-winding check.)

CAUTION: Do not check winding at compressor terminals with pressure in the system. Check resistance by removing wires attached at the compressor contactor and run capacitor.

3. Obtain a start capacitor in the range of 150–180µF[@0330] volts rating. Connect 8–gauge wires with insulated clips or terminals to the H and C terminals of the run capacitor.

4. Turn power on to unit. If compressor starts, immediately remove start-capacitor wires from H and C terminals of run capacitor, using a pair of insulated, needle-nose pliers. DO NOT leave start capacitor attached to run capacitor for more than 3 seconds, even if compressor doesn’t start.

5. Discharge start capacitor by using a pair of insulated, needle-nose pliers and shorting a 15,000 ohm, 2 watt resistor across terminals.

NOTE: Some start capacitors already have a bleed resistor attached. If so, it will discharge itself over a short period of time.

6. Run compressor 10 minutes. Stop and allow unit to sit idle for 5 minutes.

7. Check system pressure equalization.

8. Attempt to restart without capacitance boost.

If PTC thermistor device is inadequate as start device, a start capacitor and relay may be added to system to ensure positive start. Capacitor is wired in parallel with run capacitor through normally closed set of contacts on a device called start relay. The relay coil is wired across start and common terminals of compressor. The added capacitance gets the compressor started. As compressor comes up to speed, voltage across start and common terminals increases to a value high enough to cause start relay to energize. This opens normally closed contacts and removes start capacitor from circuit. In actual practice, this occurs in a fraction of a second.

NOTE: If bleed resistor is wired across start capacitor, it must be disconnected to avoid erroneous readings when ohmmeter is applied across capacitor.

To check start relay and capacitor:

1. Turn off all power to unit.

2. Discharge start and run capacitors as outlined earlier.

3. Most start capacitors will have a 15,000 ohm, 2 watt bleed resistor. Disconnect these devices from system.

Start capacitor can be inspected visually. It is designed for short duration or intermittent duty. If left in circuit for prolonged period, start capacitor blows through a specially designed bleed hole. If it appears blown, check for welded contacts in start relay. Start capacitor can be checked by ohmmeter method discussed earlier.

Start relay is checked with ohmmeter. Check for continuity across coil of relay. You should encounter a high resistance. Since relay contacts are normally closed, you should read low resistance across them. Both PTC device and capacitor-relay start system are standard equipment on some of these units. They are also available as accessories and may be field-installed.

IV. CYCLE PROTECTOR

Solid-state cycle-protector device protects unit compressor by preventing short cycling. After a system shutdown, cycle protector provides fora5±2-minute delay before compressor restarts. On normal start-up, a 5-minute delay occurs before thermostat closes. After thermostat closes, cycle protector device provides a 3-sec delay on HN67PA025, HN67ZA003, and HN67ZA008. (See Fig. 15, 16, and 17.)

—15—

T3 T1 T2

HN67ZA002

A91438

HN67ZA008

T1 YEL T2 VIO

A94005

T3 BLK

HN67ZA003

A91439

Fig. 15—Cycle-Protector Device

Cycle-protector device is simple to troubleshoot. Only a voltmeter capable of reading 24v is needed. Device is in control circuit; therefore, troubleshooting is safe with control power (24v) on and high-voltage power off.

With high-voltage power off, attach voltmeter leads across T1 and T3 and set thermostat so that Y terminal is energized. Make sure all protective devices in series with Y terminal are closed. Voltmeter should read 24v across T1 and T3. With 24v still applied, move voltmeter lead from T1 terminal to T2 terminal across T2 and T3. After5±2minutes, voltmeter should read 24v, indicating control is functioning normally. If no time delay is encountered or device never times out, change control.

V. CRANKCASE HEATER

Crankcase heater is a device for keeping compressor oil warm. By keeping oil warm, refrigerant does not migrate to and condense in compressor shell when the compressor is off. This prevents flooded starts which can damage compressor.

Crankcase heaters come in 2 basic types: wraparound-(bellyband) type that is wrapped externally around compressor shell, and insertion-type that is inserted into compressor oil well in shell of compressor. Both types are used in outdoor units.

On units that have a single-pole contactor, the crankcase heater is wired parallel with the contactor contacts and in series with the compressor. (See Fig. 18.) When the contacts are open, a circuit is completed from the line side of the contactor, through the crankcase heater, through the run windings of the compressor, and to the other side of the line. When the contacts are closed, there is

HN67PA025

A91440

no circuit through the crankcase heater because both leads are connected to the same side of the line. This allows the heater to operate when the system is not calling for heating/cooling. The heater does not operate when the system is calling for heating/cooling. On units with 2 or 3 pole contactors, the crankcase heater is connected to the line side of the contactor and is not controlled by the contactor contacts.

The crankcase heater is powered by high-voltage power of unit. Use extreme caution troubleshooting this device with power on. The easiest method of troubleshooting is to apply voltmeter across crankcase heater leads to see if heater has power. Do not touch heater. Carefully feel area around crankcase heater. If warm, crankcase heater is probably functioning. Do not rely on this method as absolute evidence heater is functioning. If compressor has been running, the area will still be warm. With power off and heater leads disconnected, check across leads with ohmmeter. Do not look for a specific resistance reading. Check for resistance or an open circuit. Change heater if an open circuit is detected. Some crankcase heaters in this series of units are equipped with a crankcase-heater switch. This energy-saving device shuts off power to heater when temperatures are high enough that heater is not needed. Be sure this switch is functioning normally before condemning crankcase heater.

VI. TIME-DELAY RELAY

The time-delay relay (TDR) is a solid-state-controlled, recycledelay timer which keeps the indoor blower operating for 90 sec after thermostat is satisfied. This delay enables the blower to remove residual cooling in the coil after compression shutdown,

—16—

OPERATING

TIME

5 MIN

SEC

OPERATING

TIME

5 MIN

BLK DENOTES CLOSED CONTACTS

HN67ZA002

YEL

TERMINAL BOARD CONNECTION

SAFETY CONTROL

A91436

Fig. 16—Cycle-Protector Sequence

CUT YELLOW WIRE

BETWEEN CONTACTOR AND

LOW-PRESSURE SWITCH

YEL C BRNYEL

YEL

T1 T3

LOGIC

VIO

Fig. 17—Cycle-Protector Wiring

BLK DENOTES CLOSED CONTACTS

HN67PA025, HN67ZA003, HN67ZA008

A91437

TERMINAL

BOARD

CONNECTION

BLK

A88415

DSV

2111

A91426

Fig. 18—Wiring for Single-Pole Contactor

thereby improving the efficiency of the system. The sequence of operation is that on closure of the wall thermostat and at the end of a fixed on-delay of 1 sec, the fan relay is energized. When the thermostat is satisfied, an off-delay is initiated. When the fixed delay of 90 ± 20 sec is completed, the fan relay is de-energized and fan motor stops. If the wall thermostat closes during this delay, the

TDR is reset, and the fan relay remains energized. The TDR is a 24v device that operates within a range of 15 to 30v and draws about 0.5 amps.

If the blower runs continuously instead of cycling off when the fan switch is set on AUTO, the TDR is probably defective and must be replaced.

VII. PRESSURE SWITCHES

Pressure switches are protective devices wired into control circuit (low voltage). They shut off compressor if abnormally high or low pressures are present in the refrigeration circuit. Depending on unit model, you may find a low- and/or high-pressure switch in system.

LOW-PRESSURE SWITCH Located on suction line of condensing unit only, the low-pressure

switch protects against low-suction pressures caused by such events as loss of charge, low airflow across indoor coil, dirty filters, etc. It opens on a pressure drop at about 27 psi. If system pressure is above this, switch should be closed. To check switch, turn off all power to unit, disconnect leads on switch, and apply ohmmeter leads across switch. You should have continuity on a good switch. Because these switches are attached to refrigeration system under pressure, it is not advisable to remove this device for troubleshooting unless you are reasonably certain that a problem exists. If switch must be removed, remove and recover all system charge so that pressure gages read 0 psi.

—17—

CAUTION: Wear safety glasses and gloves when working with refrigerants.

Apply heat with torch to solder joint and remove switch. Wear safety glasses when using torch. Have quenching cloth available. Oil vapor in line may ignite when switch is removed. Braze in 1/4-in. flare fitting and screw on replacement pressure switch.

HIGH-PRESSURE SWITCH Located on discharge line, the high-pressure switch protects

against high-discharge pressures caused by such events as overcharge, condenser-fan motor failure, system restriction, etc. It opens on pressure rise at about 435 psi. If system pressures go above this setting during abnormal conditions, the switch opens. Do not attempt to simulate these system abnormalities as high pressures pose a serious safety hazard. High-pressure switch is also checked with an ohmmeter similar to checking low-pressure switch. If system pressure is below 435 psi, the switch shows continuity. It is replaced in the same manner as low-pressure switch. Observe all safety precautions.

LIQUID-LINE PRESSURE SWITCH Located on liquid line of heat pump only, the liquid-line pressure

switch functions similar to conventional low-pressure switch. Because heat pumps experience very low suction pressures during normal system operation, a conventional low-pressure switch cannot be installed on suction line. This switch is installed in liquid line instead and acts as loss-of-charge protector. The liquid line is the low side of the system in heating mode. It operates identically to low-pressure switch except it opens at 7 psi when the heating piston is in the liquid valve or 27 psi when the heating piston is in the liquid line. Troubleshooting and removing this switch is identical to procedures used on other switches. Observe same safety precautions.

VIII. DEFROST THERMOSTATS

Defrost thermostat signals heat pump that conditions are right for defrost or that conditions have changed to terminate defrost. It is a thermally actuated switch clamped to outdoor coil to sense its temperature. Normal temperature range is closed at 30° ±3°F and open at 80° ±5°F.

NOTE: The defrost thermostat must be located on the liquid side of the outdoor coil on the bottom circuit and as close to the coil as possible.

IX. DEFROST-CONTROL BOARD

Solid-state defrost boards used on heat pumps replace electromechanical timer and defrost relay found on older defrost systems. The defrost-control board can be field-set to check need for defrost every 30, 50, or 90 minutes of operating time by connecting the jumper (labeled W1 on the circuit board) to the terminal for the defrost time desired. The board is set at factory for 90 minutes. The defrost period is field-selectable, depending upon geographic areas and defrost demands. Two types of defrost boards are used, and functions are described in the sections to follow.

Troubleshooting defrost control involves a series of simple steps that indicate whether or not board is defective.

NOTE: This procedure allows the service technician to check control board and defrost thermostat for defects. First troubleshoot to make sure unit operates properly in heating and cooling modes. This ensures operational problems are not attributed to the defrostcontrol board.

HK32FA003, 006 DEFROST CONTROL This control board utilizes screw terminals for the low-voltage

field wiring. The board has a feature that allows the heat pump to restart in defrost if room thermostat is satisfied during defrost. To troubleshoot the board, perform the following items.

1. Turn thermostat to OFF. Shut off all power to outdoor unit.

2. Remove control-box cover for access to electrical components and defrost-control board.

3. Disconnect defrost-thermostat leads from control board and connect to ohmmeter. Thermostat leads are the black, insulated wires connected to DFT and R terminals on control board. Resistance reading may be zero (indicating closed defrost thermostat) or infinity (∞ for open thermostat) depending on outdoor temperature.

4. Jumper between DFT and R terminals on control board as shown in Fig. 19.

5. Disconnect outdoor fan motor lead from OF2. Tape lead to prevent grounding.

6. Turn on power to outdoor unit.

7. Restart unit in heating, allowing frost to accumulate on outdoor coil.

8. After a few minutes in heating, liquid-line temperature at defrost thermostat should drop below closing set point of defrost thermostat of approximately 30°F. Using ohmmeter, check resistance across defrost-thermostat leads. Resistance of zero indicates defrost thermostat is closed and operating properly.

9. Remove protective cover from TP1 and TP2 speed-up terminals. Install jumper wire on speed-up terminals. This reduces the timing sequence to 1/60 of original time. (See Fig. 20.) Since Fig. 20 shows timing cycle set at 30 minutes, unit initiates defrost within approximately 30 sec; if setting is at 50 minutes, within 50 sec; 90 minutes, within 90 sec. When you hear the reversing valve change position, remove protective cover/jumper. Otherwise, control will terminate normal 10-minute defrost cycle in approximately 10 sec.

CAUTION: Exercise extreme caution when shorting speed-up pins. If pins are accidentally grounded, damage to the control board will occur.

10. Unit is now operating in defrost mode. Using voltmeter, check between C and W2 as shown in Fig. 21. Reading on voltmeter should indicate 24v. This step ensures defrost relay contacts have closed, energizing supplemental heat (W2) and reversing valve solenoid (O).

11. Unit should remain in defrost no longer than 10 minutes. Actual time in defrost depends on how quickly speed-up jumper is removed. If it takes 3 sec to remove speed-up jumper after unit has switched to defrost, only 7 minutes of defrost cycle remains.

12. After a few minutes in defrost (cooling) operation, liquid line should be warm enough to have caused defrostthermostat contacts to open. Check resistance across defrost thermostat. Ohmmeter should read infinite resistance, indicating defrost thermostat has opened at approximately 80°F.

13. Shut off unit power and reconnect fan lead.

14. Remove jumper wire from speed-up terminal and reinsert cover on speed-up terminals. Failure to remove jumper causes unit to speed up operating cycles continuously.

15. Remove jumper between DFT and R terminals. Reconnect defrost thermostat leads.

16. Replace control-box cover. Restore power to unit.

If defrost thermostat does not check out following above items or incorrect calibration is suspected, check for a defective thermostat as follows.

1. Follow items 1-5 above.

—18—

W2 L

OF2

OF1

R Y

OF2

OF1

T2 YTIDFTCTEST

50 90

HK32FA003/HK32FA006

DFT

A88402

Fig. 19—Jumper DFT and R Terminals

2. Using thermocouple temperature-measuring device, route sensor or probe underneath coil (or other convenient location). Attach to liquid line near defrost thermostat. Insulate for more accurate reading.

3. Turn on power to outdoor unit.

4. Restart unit in heating mode.

5. Within a few minutes, liquid-line temperature drops within a range causing defrost thermostat contacts to close. Temperature range is from 33°Fto27°F. Notice temperature at which ohmmeter reading goes from ∞ to zero ohms. Thermostat contacts close at this point.

6. Remove protective cover from TP1 and TP2 speed-up terminals, and install jumper wire on the speed-up terminals.

7. Unit changes over to defrost within 90 sec (depending on timing cycle setting). Liquid-line temperature rises to range where defrost thermostat contacts open. Temperature range is from 75°Fto85°F. Resistance goes from zero to ∞ when contacts open.

8. If either opening or closing temperature does not fall within above ranges or thermostat sticks in 1 position, replace thermostat to ensure proper defrost operation.

CES0110063 DEFROST CONTROL Some heat pumps built in 1991 and later incorporate a new defrost

control. The screw terminals found on the previous control board have been replaced by a connector plug with stripped-wire leads. This control board also contains the feature that allows the heat pump to restart in defrost if the room thermostat is satisfied during defrost. The board also contains a 5-minute cycle protector that prevents the unit from short cycling after it cycles off or after a power interruption. To troubleshoot the board, perform the following items.

1. Turn thermostat to OFF. Shut off all power to outdoor unit.

2. Remove control-box cover for access to electrical components and defrost-control board.

3. Disconnect defrost-thermostat leads from control board, and connect to ohmmeter. Thermostat leads are the black, insulated wires connected to DFT and R terminals on control board. Resistance reading may be zero (indicating closed-defrost thermostat), or infinity (∞ for open thermostat) depending on outdoor temperature.

O R

CES0110063, CES0130024

A91442

4. Jumper between DFT and R terminals on control board as shown in Fig. 21.

5. Disconnect outdoor fan-motor lead from OF2. Tape lead to prevent grounding.

6. Turn on power to outdoor unit.

7. Restart unit in heating mode, allowing frost to accumulate on outdoor coil.

8. After a few minutes in heating mode, liquid-line temperature at defrost thermostat should drop below closing set point of defrost thermostat of approximately 30°F. Check resistance across defrost thermostat leads using ohmmeter. Resistance of zero indicates defrost thermostat is closed and operating properly.

9. Short between the speed-up terminals using a thermostat screwdriver. This reduces the timing sequence to 1/256 of original time. (See Fig. 20 and Table 10.)

NOTE: Fig. 20 shows timing cycle set at 30 minutes; however, for the CES30110063 board the timing cycle will be set for 90 min and unit initiates defrost within approximately 21 sec. When you hear the reversing valve change position, remove screwdriver immediately. Otherwise, control will terminate normal 10-minute defrost cycle in approximately 2 sec.

CAUTION: Exercise extreme caution when shorting speed-up pins. If pins are accidentally shorted to other terminals, damage to the control board will occur.

10. Unit is now operating in defrost mode. Check between C and W2 using voltmeter as shown in Fig. 21. Reading on voltmeter should indicate 24v. This step ensures defrostrelay contacts have closed, energizing supplemental heat (W2) and reversing valve solenoid (O).

11. Unit should remain in defrost no longer than 10 minutes. Actual time in defrost depends on how quickly speed-up jumper is removed. If it takes 2 sec. to remove speed-up jumper after unit has switched to defrost, the unit will switch back to heat mode.

—19—

L W3

OF1

OF2

OF1

C C

DFT

HK32FA003/HK32FA006

A88404

Fig. 20—Inserting Jumper Wire

OF2

OF1

R R

C C

DFT

HK32FA003/HK32FA006

A88403

Fig. 21—Checking Between C and W2

13. Shut off unit power and reconnect fan lead.

14. Remove jumper between DFT and R terminals. Reconnect defrost-thermostat leads. Failure to remove jumper causes unit to switch to defrost every 30, 50, or 90 minutes and remain in defrost for full 10 minutes.

15. Replace control-box cover. Restore power to unit.

If defrost thermostat does not check out following above items or incorrect calibration is suspected, check for a defective thermostat as follows.

1. Follow items 1-5 above.

2. Route sensor or probe underneath coil (or other convenient location) using thermocouple temperature-measuring device. Attach to liquid line near defrost thermostat. Insulate for more accurate reading.

3. Turn on power to outdoor unit.

T2 YTIDFT

O R

Y C

TEST

50 90

CES0110063,

CES0130024

A91444

OF2

OF1

T2 YTIDFT

O R

50 90

TEST

CES0110063, CES0130024

A91443

TABLE 10—DEFROST CONTROL SPEED-UP TIMING SE-

QUENCE FOR CES0110063/CES0130024

PARAMETER MINIMUM MAXIMUM

30-minute cycle 27 33 7 sec 50-minute cycle 45 55 12 sec 90-minute cycle 81 99 21 sec 10-minute cycle 9 11 2 sec

5 minutes 4.5 5.5 1 sec

SPEED-UP

(NOMINAL)

4. Restart unit in heating.

5. Within a few minutes, liquid-line temperature drops within a range causing defrost-thermostat contacts to close. Temperature range is from 33°Fto27°F. Notice temperature at which ohmmeter reading goes from ∞ to zero ohms. Thermostat contacts close at this point.

—20—

6. Short between the speed-up terminals using a small, slotted screwdriver.

7. Unit changes over to defrost within 21 sec (depending on timing-cycle setting). Liquid-line temperature rises to range where defrost-thermostat contacts open. Temperature range is from 75°Fto85°F. Resistance goes from zero to ∞ when contacts open.

8. If either opening or closing temperature does not fall within above ranges or thermostat sticks in 1 position, replace thermostat to ensure proper defrost operation.

CES0130024 DEFROST CONTROL Some heat pumps built in 1993 and later incorporated a new

defrost control similar to the CES0110063 except the 5-minute cycle protector has been removed. This control is used on heat pump units with reciprocating compressors where short-cycle protection is not required.

Troubleshooting this control will be the same as the CES0110063 control except for the cycle-protector function. The CES0130024 control is identical to the CES0110063 except the T2 terminal and cycle-protector logic have been removed.

CES0130076 DEFROST CONTROL This defrost control is the same size as the CES0130063 control

but is not backwards-compatible. (See Fig. 22.) To upgrade to the new control, you must have replacement-defrost thermostat and harness kit. See your replacement-component representative for kit part number.

Defrost Settings The defrost control is a time/temperature control which includes a

field-selectable time period (DIP switch 1 and 2 on board, see Table 11) between defrost cycles of 30, 60, 90, and 120 minutes (factory-set at 90 minutes).

TABLE 11—DEFROST TIMER SETTINGS

SW1 SW2 SW3

On Off 30 Off On 60 Off Off 90 On On 120

To initiate a forced defrost, two options are available, depending on the status of the defrost thermostat.

If defrost thermostat is closed, speedup pins (J1) must be shorted by placing a Flathead screwdriver in between for 5 seconds and releasing, to observe a complete defrost cycle. When the Quiet Shift switch is selected, compressor will be turned off for two, 30–second intervals during this complete defrost cycle. When Quiet Shift switch is in factory-default OFF position, a normal and complete defrost cycle will be observed.

If defrost thermostat is in open position and speedup pins are shorted (with a Flathead screwdriver) for 5 seconds and released, a short defrost cycle will be observed (actual length is dependent upon the selected Quiet Shift position). When Quiet Shift switch is in ON position, the length of defrost is 1 minute (30 seconds compressor-off period followed by 30 seconds of defrost with compressor operation). On return to heat operation, compressor will again turn off for an additional 30 seconds and the fan for 40 seconds. When the Quiet Shift is in OFF position, only a brief 30–second cycle will be observed.

If it is desirable to observe a complete defrost in warmer weather, the thermostat must be closed as follows.

1. Turn off power to outdoor unit.

2. Disconnect outdoor fan-motor lead from OF2 on control board. (See Fig. 22.) Tape to prevent grounding.

3. Restart unit in heating mode, allowing frost to accumulate on outdoor coil.

4. After a few minutes in heating mode, liquid-line temperature should drop below closing point of defrost thermostat (approximately 30° F.

NOTE: Unit will remain in defrost until defrost thermostat reopens at approximately 80° F coil temperature at liquid line or remainder of defrost cycle time.

5. Turn off power to outdoor unit and reconnect fan-motor lead to OF2 on control board after above forced-defrost cycle.

Compressor Shut Down This control has the option of shutting down the compressor for 30

seconds while going into and out of defrost modes. This is accomplished by turning DIP switch 3 to the ON position. See Fig. 22 for switch position. Factory default is in the OFF position.

Five-Minute Time Delay This control has a 5–minute time delay on startup. The speedup

terminals can be used to bypass this delay. Momentary shorting across the speedup terminals will, upon release, bypass 5–minute time delay. Do not short out the speedup terminals for more than 5 seconds, or defrost mode will be initiated.

Troubleshooting Troubleshooting this control is done in the same manner as the

CES0130063 control with the exceptions listed above. DEFROST THERMOSTAT LOCATION On most residential, outdoor heat-pump models, the defrost

thermostat is located on the return-bend side of the coil. The 5/16 OD feeder tube from the header will enter a 1–1/2 in. to 2–in. long 3/8 OD stub prior to entering the coil. There is only one stub tube per coil. All other feeder tubes enter the coil directly. The defrost thermostat attaches to this stub tube. (See Fig. 23.)

X. FAN MOTORS

Fan motor rotates the fan blade that either draws or blows air through outdoor coil to perform heat exchange. Motors are totally enclosed to increase reliability. This also eliminates need for rain shield. For the correct position of the fan blade assembly, see Fig. 24 and Table 12.

WARNING: Turn off all power to unit before servicing or replacing fan motor. Be sure unit main power switch is turned off. Failure to do so may result in electric shock, death, or injury from rotating fan blade.

The bearings are permanently lubricated; therefore, no oil ports are provided.

For suspected electrical failures, check for loose or faulty electrical connections, or defective fan-motor capacitor. Fan motor is equipped with thermal overload device in motor windings which may open under adverse operating conditions. Allow time for motor to cool so device can reset. Further checking of motor can be done with an ohmmeter. Set scale onRX1position; check for continuity between 3 leads. Replace motors that show an open circuit in any of the windings. Place 1 lead of ohmmeter on each motor lead. At same time, place other ohmmeter lead on motor case (ground). Replace any motor that shows resistance to ground, signs of arcing, burning, or overheating.

XI. SERVICE ALARM CONTROL BOARD NOTE: If the proper night-setback thermostat is not used, the

service-alarm control will work, but there will be no light indication on thermostat.

The service-alarm control provides immediate warning when outdoor heat pump requires servicing. It turns on indoor thermostat-malfunction light if compressor does not operate for

—21—

O R W

Y C

SPEEDUP

T2 C C O

DFT

T1 Y

DFT

INTERVAL TIMER

OFF

SHIFT

OF1

OF2

120

QUIET

Speedup Pins

either heating or cooling. This enables owner to obtain timely heat-pump service during heating season, reducing supplementary electric heat costs, and during cooling season, reducing period of heat discomfort.

The service alarm is an accessory device. Service alarm locks out compressor under certain adverse operating conditions. System is manually reset by shutting it off at thermostat subbase, then turning it back on. If adverse condition is corrected, system restarts.

One example of an adverse condition would be a system located in a desert climate where high operating temperatures may cause system to shut down on the high-pressure switch or on the compressor internal overload.

Connect service alarm to outdoor-unit control-circuit-terminal board. (See Fig. 25 and wiring diagram on unit.)

Connect all field line-power wires to unit in usual manner. Route 1 field line-power supply wire through metallic loop on bottom of service alarm then to normal unit connection. Units with RLA of less than 14 amps will require 2 passes through the metallic loop.

Refer to Fig. 25 or 26 for wiring connections for service alarm or service alarm with solid-state cycle-protector accessories, when used.

NOTE: The wire from the X terminal on the service alarm to L on the outdoor terminal board, indoor terminal board, and thermostat subbase is field-supplied and wired when using defrost controls HK32FA003 or HK32FA006. When defrost control CES0110063 or CES0130024 is used, field-supplied wire from X terminal on service alarm to L on indoor thermostat subbase is required.

Quiet Shift

Fig. 22—Defrost Control

CESO130076–00

Defrost interval DIP switches

A99442

Service alarm requires 2 inputs.

1. It must sense a 24v input from thermostat. As thermostat calls for heating or cooling, it supplies 24v to service-alarm device.

2. A current transformer (or induction loop) similar to a clamp-on ammeter senses current draw in the compressor lead. Induction loop must sense a minimum current draw when thermostat is calling for heating or cooling.

NOTE: On a single-phase compressor, induction loop senses current in common leg. On a 3-phase compressor, induction loop senses current in any 1 of the phases.

WARNING: If service alarm needs replacing, shut off all power to unit before attempting removal. Electrical shock can cause personal injury or death.

Troubleshooting service-alarm device is easy. With thermostat calling for heating or cooling and compressor running, indoor thermostat light should be off. If on, check for wiring errors or replace the service alarm. To check for correct operation, shut off circuit breaker or disconnect switch to outdoor unit while it is running. Signal light on thermostat should light. If this does not occur, check for wiring errors or replace the service alarm.

XII. OUTDOOR THERMOSTAT(S)

The outdoor thermostat(s) is installed in the control box. The sensing bulb(s) remain in the control box. Outdoor thermostat brings on stages of electric heat as outdoor temperature and

—22—

TABLE 12—FAN POSITION

AEROQUIET SYSTEM AND AEROMAX TOP

Fan Motor Part No. Fan Blade Part No.

HC29GE208

HC31GE230/231

HC33GE208 LA01EW049 5–1/4 — HC33GE232 LA01RA015 4–29/32 4–17/32 HC34GE231 HC34GE460 HC35GE208 LA01EW048 4–15/16 —

HC35GE232

HC37GE208 LA01EA025 6–1/8 6–1/8 HC37GE230 LA01EW046 6–5/32 6–1/8 HC38GE221 LA01EA031 7–25/32 —

HC39GE232

HC39GE234

HC39GE461

HC40GE230 LA01EA024 5–9/32 5–11/32 HC40GE461 LA01EA024 5–27/32 5–19/32

LA01EB023 4–5/32 — LA01EC019 5–1/8 — LA01EA026 4–5/8 — LA01RA015 4–7/8 4–5/8

LA01RA015 5–5/32 4–25/32

LA01EA025 5–7/8 — LA01RA024 5–11/32 5–3/32 LA01RA026 5–9/16 4–11/16

LA01EC018 5–11/16 — LA01RA026 5–1/2 4–3/4 LA01EA036 5–9/16 — LA01EA024 5–3/32 4–27/32 LA01EC018 5–1/2 — LA01EA036 6–1/16 — LA01EC018 6–1/4 — LA01RA026 6–1/16 5–7/32

Brookside Revcor

Dimension A (In.)

FEEDER TUBE

STUB TUBE

DEFROST THERMOSTAT

Fig. 23—Defrost Thermostat Location

A97517

BASKET TOP

A91428

Fig. 24—Fan Position

—23—

24-VOLT WIRING

BRN

HIGH AND/OR LOW PRESSURE

AND/OR DISCHARGE TEMPERATURE

SWITCH (IF USED)

DTS

HPS

BLUBLU

LPS

YEL

OUTDOOR

UNIT

TERMINAL

BOARD

THERMOSTAT

SUBBASE

INDOOR

UNIT

TERMINAL

BOARD

PASS SUPPLY WIRE THROUGH METALLIC LOOP TWICE ON UNITS WITH NAMEPLATE RLA OF 14 AMPS OR LESS.

Fig. 25—Service Alarm Wiring Connections

FIELD LINE VOLTAGE SUPPLY WIRE

CYCLE PROTECTOR SERVICE ALARM

YEL

T2 T3 X 3 2 1

BLKVIO

L C C C

OUTDOOR

UNIT

TERMINAL

BOARD

BLK BLK

BRN

THERMOSTAT

SUBBASE

INDOOR

UNIT

TERMINAL

BOARD

Fig. 26—Wiring Connections for Service Alarm and Cycle Protector

heat-pump output drops. Setting at which thermostat closes is variable, depending on design of system. It is set at time of installation and should not be changed without cause. Up to 2 outdoor thermostats may be installed. Some systems may not have any thermostat. An outdoor thermostat can also be used to lock out compressor operation at low ambients in condensing unit not equipped with low-ambient control.

Although these devices are installed in control circuit (24v), turn off all power to unit before attempting to troubleshoot thermostat.

Use a standard ohmmeter to check for continuity through thermostat. If you suspect thermostat is out of calibration, use calibrated electronic thermometer to determine correct outdoor temperature. Turn thermostat dial knob until switch closes. Observe this using ohmmeter across switch. Read temperature setting when switch closes. It should be close to reading observed using electronic thermometer. Any setting within ± 5°F is acceptable.

BLK

*METALLIC

LOOP

ORN REDYEL

21 3 X

SERVICE ALARM

AND/OR DISCHARGE TEMPERATURE

ORN

YEL

COMMON POTENTIAL FACTORY WIRING (FIELD CONNECTED) FIELD-SUPPLIED WIRING CONTACTOR

XIII. COMPRESSOR PLUG

The compressor electrical plug provides a quick-tight connection to the compressor terminals. The plug completely covers the compressor terminals, and the mating female terminals are completely encapsulated in the plug. Therefore, the terminals are isolated from any moisture so corrosion and resultant pitted or discolored terminals are reduced. The plug is oriented to the relief slot in the terminal box so the cover cannot be secured if wires are not positioned in slot, assuring correct electrical connection at the compressor. The plug can be removed by simultaneously pulling while ″rocking″ the plug. However, these plugs are specialized and vary in terminal orientation in the plug. Therefore, plugs can be used on only the specific compressor or group as shown in Fig. 27.

For the Carlyle and Bristol compressors in Fig. 27, the triangle formed by the fusite terminals points down, and the plug is likewise oriented. The fusite terminals and plug-terminal orienta-

ONE FIELD LINE VOLTAGE SUPPLY WIRE

HIGH AND/OR LOW PRESSURE

SWITCH (IF USED)

DTS

YEL BLU BLU

LPS

HPS

A88340

BRN

A88339

—24—

tion shown for the Tecumseh compressor is shown with the triangle formed by the terminals pointing toward the top. The configuration around the fusite terminals is the outline of the terminal covers used on the specific compressors. The slot through which the wires of the plug are routed is oriented on the bottom or slightly to the left or right. The correct plug can be connected easily to the compressor terminals and plug wires routed easily through the slot in the terminal cover. Therefore, if a Carlyle or Bristol compressor is substituted for a Tecumseh compressor, a new plug must be installed. If the plug is not changed, proper connection and routing of the plug wires through the terminal cover will be impossible.

CARLYLE

LEAD 3 BLUE

LEAD 1 BLK.

BRISTOL

COPELAND

LEAD 2 YEL.

G—Energizes blower circuit from indoor thermostat. E—Energizes emergency-heat relay. W2—Energizes first-stage supplemental heat through defrost relay (wht). L—Energizes light on thermostat with service alarm. W3—Energizes second- or third-stage supplemental heat. R—Energizes 24v power from transformer (red). Y—Energizes contactor for first-stage cooling or first-stage heating for heat pumps (yel). O—Energizes reversing valve on heat pumps (orn). C—Common side of transformer (blk).

RECIPROCATING COMPRESSOR

The compressor is the heart of the refrigeration system. It pumps refrigerant through the system. If it malfunctions, system capacity and efficiency could be negatively affected.

CAUTION: The compressor is an electrical (as well as mechanical) device. Exercise extreme caution when working near compressors. Power should be shut off, if possible, for most troubleshooting techniques. Refrigerants in system present other safety hazards. Always wear safety glasses and gloves when handling refrigerants.

TECUMSEH

LEAD 1 BLK.

LEAD 2 YEL.

LEAD 3 BLUE

LEAD 2 YEL.

A94002

LEAD 3 BLUE

TECUMSEH

LEAD 2 YEL.

MILLENNIUM

LEAD 1 BLK.

Fig. 27—Compressor Plug

XIV. LOW-VOLTAGE TERMINALS

The low-voltage terminal designations, along with descriptions and/or functions, are used on all split-system condensers and heat pumps:

Compressor failures are classified in 2 broad failure categories: mechanical and electrical. Both types are discussed below.

I. MECHANICAL FAILURES

A compressor is a mechanical pump driven by an electric motor contained in a welded or hermetic shell. In a mechanical failure, motor or electrical circuit appears normal, but compressor does not function normally.

CAUTION: Exercise extreme caution when reading compressor currents when high-voltage power is on. Correct any of the problems described below before installing and running a replacement compressor. Wear safety glasses and gloves when handling refrigerants.

LOCKED ROTOR In this type of failure, compressor motor and all starting compo-

nents are normal. When compressor attempts to start, it draws locked-rotor current and cycles off on the internal protection. Locked-rotor current is measured by applying a clamp-on ammeter around common (blk) lead of the compressor on a single-phase compressor, or any 1 of the leads on a 3-phase compressor. Current drawn when it attempts to start is then measured. LRA (lockedrotor amp) value is stamped on compressor nameplate.

If compressor draws locked-rotor amps and all other external sources of problems have been eliminated, compressor must be replaced. Because compressor is a sealed unit, it is impossible to determine exact mechanical failure. However, complete system should be checked for abnormalities such as incorrect refrigerant charge, restrictions, insufficient airflow across indoor or outdoor coil, and so forth, which could be contributing to the failure.

RUNS, DOES NOT PUMP In this type of failure, compressor motor runs and turns compres-

sor, but compressor does not pump the refrigerant. A clamp-on ammeter on common leg of a single-phase compressor, or any 1 lead of a 3-phase compressor, shows a very low current draw, much lower than RLA (rated load amps) value stamped on compressor nameplate. Because no refrigerant is being pumped, there is no return gas to cool compressor motor. It eventually overheats and shuts off on its internal protection.

RUNS, DOES NOT PUMP, HIGH-TO-LOW SIDE LEAK

—25—

POWER OFF!

(EXAMPLE) TO DETERMINE INTERNAL CONNECTIONS OF SINGLEPHASE MOTORS (C,S,R) EXCEPT SHADED-POLE

DEDUCTION:

1 3 (GREATEST RESISTANCE)

5.8Ω (OHM)

RUN WINDING (R) START WINDING (S)

5.2Ω 2

OHMMETER 0-10Ω SCALE

0.6Ω 3

5.8Ω

Fig. 28—Identifying Internal Connections

In this type of failure, compressor motor runs and turns compressor, and compressor is pumping. Usually, an internal problem such as blown head gasket or broken internal-discharge line causes compressor to pump hot discharge gas back into its own shell rather than through system.

Using pressure gages on service valves shows high suction and low discharge pressure readings. Motor currents are lower than normal. Because hot gas is being discharged into shell, the shell becomes hot. The hot gas causes compressor motor to cycle off on its internal protection.

RUNS AND PUMPS, LOW CAPACITY This failure type is difficult to pinpoint because extent of damage

varies. Compressor is a pump with internal valves that enable compressor to pump properly. The cylinder has a set of suction and discharge valves. Any of these parts may become damaged or broken, causing loss in pumping capacity. Severity of damage determines amount of capacity loss. Use pressure gages to find any abnormal system pressures if system charge and other conditions are normal.

An owner may complain that a unit is not handling the building’s heating or cooling load. The compressor current draw may be abnormally low or high. Although this type of failure does occur, all other possible causes of capacity loss must be eliminated before condemning compressor.

NOISY COMPRESSOR Noise may be caused by a variety of internal problems such as

loosened hardware, broken mounting springs, etc. System problems such as overcharged compressor (especially at start-up) or too much oil in compressor may also cause excessive noise. Excess oil in compressor is normally encountered only after a replacement compressor has been added without purging oil from previous compressor. As new compressor pumps, excess oil in system returns and adds to volume already present, causing noise.

COMPRESSOR LEAKS

CAUTION: Use safety glasses and gloves when handling refrigerants.

Sometimes a leak is detected at weld seam around girth of compressor or a fitting that joins compressor shell. Many of these leaks can be repaired and the compressor saved if correct procedure is followed.

1. Turn off all power to unit.

(SMALLEST RESISTANCE)

0.6Ω

(REMAINING RESISTANCE)

5.2Ω

2. Remove and recover all refrigerant from system so that gage pressures are 0 psi.

3. Clean area around leak to bare metal.

4. Apply flux and repair joint with silver solder. Do not use low-temperature solder such as 50-50.

5. Clean off excess flux, check for leaks, and apply paint over repaired area to prevent corrosion.

Do not use this method to repair a compressor leak due to severe corrosion. Never attempt to repair a compressor leaking at electric terminals. This type of failure requires compressor replacement.

II. ELECTRICAL FAILURES

The compressor mechanical pump is driven by an electric motor within its hermetic shell. In electrical failures, compressor does not run although external electrical and mechanical systems appear normal. Compressor must be checked electrically for abnormalities.

Before troubleshooting compressor motor, review this description of compressor motor-terminal identification.

SINGLE-PHASE MOTORS To identify terminals C, S, and R:

1. Turn off all unit power.

2. Short the run and start capacitors to prevent shock.

3. Remove all wires from motor terminals.

4. Read resistance between all pairs of terminals using an ohmmeter on 0-10 ohm scale.

5. Determine 2 terminals that provide greatest resistance reading.

Through elimination, remaining terminal must be common (C). Greatest resistance between common (C) and another terminal indicates start winding because it has more turns. This terminal is start (S). Remaining terminal will be run winding (R). (See Fig.

28.) NOTE: If compressor is hot, allow time to cool and internal line

break to reset. There is an internal line-break protector which must be closed. THREE-PHASE MOTORS Resistance readings between all 3 sets of windings should be the same. All compressors are equipped with internal motor protection. If motor becomes hot for any reason, protector opens. Compressor should always be allowed to cool and protector to close before troubleshooting. Always turn off all power to unit and disconnect leads at compressor terminals before taking readings.

IS COMMON (C) BY ELIMINATION

IS COMMON, THEREFORE, IS

START WINDING (S) IS RUN WINDING (R)

A88344

—26—

Most common motor failures are due to either an open, grounded, or short circuit. Directions below are specifically for single-phase units, however, they also apply to 3-phase compressors. When a single-phase compressor fails to start or run, 3 tests can help determine the problem. First, all possible external causes should be eliminated, such as overloads, improper voltage, pressure equalization, defective capacitor(s), relays, wiring, and so forth. Compressor has internal line-break overload, so be certain it is closed.

OPEN CIRCUIT To determine if any winding has a break in the internal wires and

current is unable to pass through:

1. Be sure all power is off.

2. Discharge all capacitors.

3. Remove wires from terminals C, S and R.

4. Check resistance from C-R, C-S and R-S using an ohmmeter on 0-1000 ohm scale.

Because winding resistances are usually less than 10 ohms, each reading appears to be approximately 0 ohm. If resistance remains at 1000 ohms, an open or break exists, and compressor should be replaced.

CAUTION: Be sure internal line-break overload is not temporarily open.

4. Motor must be dry or free from direct contact with liquid refrigerant.

MAKE THIS CRITICAL TEST (Not advisable unless above conditions are met.)

1. Be sure all power is off.

2. Discharge all capacitors.

3. Remove wires from terminals C, S, and R.

4. Place instrument probes together and determine probe and lead wire resistance.

5. Check resistance readings from C-R, C-S, and R-S.

6. Subtract instrument probe and lead resistance from each reading.

If any reading is within ± 20 percent of known resistance, motor is probably normal. Usually a considerable difference in reading is noted if a turn-to-turn short is present.

III. SYSTEM CLEANUP AFTER BURNOUT

CAUTION: Turn off all power to unit before proceed-

ing. Wear safety glasses and gloves when handling refrigerants. Acids formed as a result of motor burnout can cause burns.

GROUND CIRCUIT To determine if a wire has broken or come in direct contact with

shell, causing a direct short to ground:

1. Be sure all power is off.

2. Discharge all capacitors.

3. Remove wires from terminals C, S, and R.

4. On hermetic compressors, allow crankcase heaters to remain on for several hours before checking motor to ensure windings are not saturated with refrigerant.

5. Use an ohmmeter on R X 10,000 ohm scale. A megohmmeter may be used in place of ohmmeter. Follow manufacturer’s instructions.

6. Place 1 meter probe on ground or on compressor shell. Make a good metal-to-metal contact. Place other probe on terminals C, S, and R in sequence.

7. Note meter scale.

8. If reading of zero or low resistance is obtained, motor is grounded. Replace compressor.

A 1 ton or less capacity compressor is probably grounded if resistance is below 1 million ohms. On larger-sized, single-phase compressors, resistance to ground should not be less than 1000 ohms per volt of operating voltage. Example: 230 volts X 1000 ohms/volt = 230,000 ohms minimum.

SHORT CIRCUIT To determine if any wires within windings have broken through

their insulation and made contact with other wires, thereby shorting all or part of the winding(s), be sure the following conditions are met:

1. Correct motor-winding resistances must be known before testing, either from previous readings or from manufacturer’s specifications.

2. Temperature of windings must be as specified, usually about 70°F.

3. Resistance-measuring instrument must have an accuracy within±5to10percent. This requires an accurate ohmmeter, such as a Wheatstone bridge or null balance-type instrument.

NOTE: To analyze level of suspected contamination from compressor burnout, use Total Test. See your distributor/branch.

Some compressor electrical failures can cause motor to overheat. When this occurs, by-products, which include sludge, carbon, and acids, can contaminate system. If burnout is severe enough, system must be cleaned before replacement compressor is installed. The 2 types of motor burnout are classified as mild or severe.

In mild burnout, there is little or no detectable odor. Compressor oil is clear or slightly discolored. An acid test of compressor oil will be negative. This type of failure is treated the same as mechanical failure. Liquid-line strainer should be removed and liquid-line filter drier installed.

In a severe burnout, there is a strong, pungent, rotten-egg odor. Compressor oil is very dark. Evidence of burning may be present in tubing connected to compressor. An acid test of compressor oil will be positive. Complete system must be reverse flushed with refrigerant. Check-Flo-Rater™ or TXV must be cleaned or replaced. In a heat pump, accumulator and reversing valve are replaced. These components are also removed and bypassed during reverse-flushing procedure. Remove and discard liquid-line strainer. After system is reassembled, install liquid-line and suction-line filter driers. Run system for 2 hrs. Discard both driers and install new liquid-line drier only.

IV. COMPRESSOR REMOVAL AND REPLACEMENT

Once it is determined that compressor has failed and the reason established, compressor must be replaced.

CAUTION: Wear safety glasses and gloves when handling refrigerants and when using brazing torch.

1. Shut off all power to unit.

2. Remove and recover all refrigerant from system until pressure gages read zero psi. Use all service ports.

3. Disconnect electrical leads from compressor. Disconnect or remove crankcase heater and remove compressor-holddown bolts.

4. Cut compressor from system with tubing cutters. Do not use brazing torch for compressor removal. Oil vapor may ignite when compressor is disconnected.

—27—

5. Scratch matching marks on stubs in old compressor. Make corresponding marks on replacement compressor.

6. Use torch to remove stubs from old compressor and to reinstall them in replacement compressor.

7. Use copper couplings to tie compressor back into system.

8. Evacuate system, recharge, and check for normal system operation.

9. Copeland CR-6 and scroll compressors have copper-plated, steel-suction ports. Excess heat during brazing will burn off copper plating. See Brazing section for additional information.

COPELAND SCROLL COMPRESSOR

I. FEATURES

The scroll compressor pumps refrigerant through the system by the interaction of a stationary and an orbiting scroll. (See Fig. 29.) The scroll compressor has no dynamic suction or discharge valves, and it is more tolerant of stresses caused by debris, liquid slugging, and flooded starts. Due to the design of the scroll compressor, the internal compression components unload (equalize pressure) on shutdown. The white oil (Sontex 200LT) used in the scroll is compatible with 3GS oil, which can be used if additional oil is required. (See Table 13 for oil recharge requirements.)

Scroll Gas Flow

Compression in the scroll is created by the interaction of an orbiting spiral and a stationary spiral. Gas enters an outer opening as one of the spirals orbits.

The open passage is sealed off as gas is drawn into the spiral.

As the spiral continues to orbit, the gas is compressed into an increasingly smaller pocket.

TABLE 13—COMPRESSOR OIL RECHARGE

COMPRESSOR MODEL

Carlyle/Scroll

″J″ Type 44 Suniso 3GS

SC, SRD450AC 34

SR 52 SRH482, SRY482 68 SRH602, SRY602 70

Copeland

CRG3, CRH3, CRJ3, CRK3, CRL3 51

CRN5, CRP5, CRT5, CTH1, CTL1 66

CRC4, CRZ4 36

CR16K6 THROUGH CR42K6 42

*ZR18K1 19

*ZR23K1, ZR28K1 24

*ZR34K1 30 *ZR40K1 34

*ZR49K1-PFV 56

*ZR49K2-TF5, ZR49K2-TFD 56

*ZR61K2-PFV 56

*ZR61K2-TF5, ZR61K2-TFD 66

Tecumseh

AV55 50

AG 60

Bristol

H23A 52 H23B 37

H24A3, H24A4 47

H24A5 52

H25A, H26A 62

H25B, H26B, H29B 32

*Copeland scrolls are charged initially with Sontex 200LT white oil. Since this oil is not commercially available, use 3GS.

RECHARGE

(FL. OZ.)

OIL TYPE

Zerol 150

w/3 percent

Syn-O-Ad

Suniso 3GS

Suniso 3GSAW55 30

Suniso 3GS

II. TROUBLESHOOTING

Troubleshooting mechanical or electrical problems in a scroll compressor is the same as for a reciprocating compressor, except that a scroll compressor should never be allowed to pump into a

By the time the gas arrives at the center port, discharge pressure has been reached.

Actually, during operation, all six gas passages are in various stages of compression at all times, resulting in nearly continuous suction and discharge.

A90198

Fig. 29—Scroll Compressor Refrigerant Flow

vacuum. If a pumpdown procedure is used, the scroll compressor is capable of pumping into a vacuum very quickly, which could cause fusite arcing and compressor failure. See Step IV of Reciprocating Compressor section for removal and replacement.

III. DISCHARGE THERMOSTAT

Some scroll compressors have a discharge thermostat that reciprocating compressors do not have. This thermostat is mounted in a well in the top of the compressor shell to sense if the discharge temperature reaches 290°F and shuts down the compressor to prevent damage to it. When the temperature of the thermostat reaches 140°F, power is restored to the compressor.

To determine if the thermostat is operating properly, either attach the thermocouple of an electronic thermometer to the dome of the compressor near the thermostat, or remove the thermostat and place the thermocouple inside the well. The electronic thermometer must be capable of reading at least 300°F. Start the unit and let it run for at least 15 minutes to obtain normal operating conditions. Watch the thermometer to see if it is approaching 270°F. If the thermocouple is located on the dome near the discharge thermostat, there could be a 20° difference between well and dome temperatures. If the temperature approaches 270°F, repair system problem, such as low charge, blocked condenser coil, and so forth. If the temperature does not approach 270°F, replace discharge thermostat.

Replacing Discharge Thermostat To replace the discharge thermostat, refer to the Installation

Instructions packaged with the replacement discharge thermostat kit. (See Fig. 30.)

IV. DISCHARGE SOLENOID VALVE

Some larger units equipped with scroll compressors contain a solenoid valve that is piped between the discharge tube and suction tube of the compressor. The purpose of the solenoid valve is to

—28—

BLUE SEALANT

THERMAL GREASE

PLASTIC CAP

PRONG

GROMMET

THERMOSTAT

The scroll compressor is capable of pumping into a vacuum very quickly, which could cause fusite arcing and compressor failure. See Step IV of Reciprocating Compressor section for removal and replacement.

IV. SCROLL COMPRESSOR, 3–PHASE MONITOR

CES0130075 — PHASE MONITOR This control is factory-installed on all 3–phase, scroll compressor

models. (See Fig. 31 and 32.) On start-up, the control will energize the pilot relay for 2 seconds. The monitor will check for correct compressor rotation. If rotation is correct, unit will continue to run. If rotation is incorrect, the control will break the 24vac power at the contactor and an LED light on the control will flash. If LED is flashing, turn off power, reverse L1 and L3 field-power leads, and restart unit. This control will check incoming power at every restart.

TWO-SPEED SYSTEM

I. CAUTIONS AND WARNINGS

CAUTION: For proper unit operation and reliability, the

2-speed units must be installed with the factory-supplied balance port, hard shutoff TXV. Do not install with indoor coils having piston or capillary-tube metering devices.

A90198

Fig. 30—Location of Discharge Thermostat

cause a rapid pressure equalization around the compressor, thus reducing the normal shutdown sound created by reverse rotation of the scroll. The solenoid valve is normally closed and is wired across high-voltage line 1 to load terminals of the contactor. (See Fig. 18.) The solenoid-valve assembly also requires a check valve piped in the discharge tube between the solenoid-valve tee and the condenser coil, or reversing valve on heat pumps. The purpose of the check valve is to prevent refrigerant from bypassing through the solenoid valve into the suction tube when the unit cycles off.

MILLENNIUM SCROLL COMPRESSOR

I. FEATURES

The scroll compressor pumps refrigerant through the system by the interaction of a stationary and an orbiting scroll. (See Fig. 29.) The scroll compressor has no dynamic suction or discharge valves, and it is more tolerant of stresses caused by debris, liquid slugging, and flooded starts. The Millennium scroll varies from the Copeland scroll in that the Millennium has a shutdown flapper valve located between the scroll plates and the discharge head, whereas the Copeland has a check device at the discharge connection after the discharge head. The Copeland discharge head unloads when the compressor shuts down. The scroll plate actually runs backwards while it unloads.A1to3second unloading of refrigerant occurs.

The Millennium flapper valve eliminates the refrigerant unloading by not allowing the discharge head to run backwards because of its location. The Millennium scroll compressor uses Zerol 150 oil with 3 percent Syn-O-Ad and is the only oil recommended for oil recharge. See Table 13 for recharge requirements.

II. COMPRESSOR PROTECTION

Millennium scroll compressors are protected by an internal linebreak mounted on the motor windings. Internal protectors respond to overcurrent and high temperature. These protectors are automatic-reset devices containing a snap-action, bi-metal switch.

III. TROUBLESHOOTING

Troubleshooting mechanical and electrical problems in a scroll compressor is similar to a reciprocating compressor, except that a scroll compressor should never be allowed to pump into a vacuum.

CAUTION: Do not install equivalent interconnecting tubing lengths greater than 100 ft. Do not decrease or increase interconnecting tubing diameters.

CAUTION: To avoid electrical shock, bleed resistor must be connected across run capacitor. Replace if missing or damaged.

CAUTION: Contactor is mechanically interlocked. Do not disable mechanical interlock. Compressor damage may occur.

WARNING: Contactor control voltage is 240vac.

WARNING: Do not attempt to operate this equipment

below 55°F outdoor ambient temperature.

NOTE: Sections that follow describe the 598A Series B and 698A Series B products, which started production March, 1994. For 598A Series A and 698A Series A products, refer to the Split-System Service Manual dated 3–1–94, Catalog No. BDP 3356–115.

II. SYSTEM FUNCTIONS

COOLING OPERATION The 2-speed products utilize a 2-stage-cooling indoor thermostat.

With a call for first-stage cooling (Y1), the outdoor fan and low-speed compressor are energized. If low speed cannot satisfy the cooling demand, high speed will be energized (Y1 and Y2) by the second stage of the indoor thermostat. The thermostat has a 2° differential between first and second stages. After second stage is satisfied, the unit returns to low-speed operation, until first stage is satisfied, or until second stage is again required.

—29—

Fig. 31—CES0130075 3–Phase Monitor Board

A00010

EQUIP

GND

CONT

*CH

*HPS

*LPS

COMP

OFM

LOGIC

CESO130075

*LLS

CAP

CONT

LOGIC

CTD

T3T1

CONT

INDOOR

THERMOSTAT

Fig. 32—CESO130075 3–Phase Monitor Wiring Diagram

IFR

EXTERNAL POWER SUPPLY 24 V

—30—

A00011

HEATING OPERATION (HEAT PUMP ONLY) The 2-speed products utilize a 2-stage-heating indoor thermostat.

The first stage of heating is heat-pump operation (Y1). Auxiliary backup heat is controlled by second stage (W2). There is a 2° differential between first and second stage. The control board determines the compressor speed based on ambient temperature. See Table 14 for ambient temperatures at which speed changes occur. When high-speed, heat-pump heating is required, the control provides a Y2 (24vac) signal back to the thermostat to energize high-speed-indicator LED.

TABLE 14—AMBIENT TEMPERATURE FOR HIGH- AND

LOW-SPEED OPERATION

UNIT SIZE

036 30 or less 31 or greater 048 33 or less 34 or greater 060 40 or less 41 or greater

AMBIENT TEMPERATURE (°F)

High Speed Low Speed

LED FUNCTION LIGHTS When using the factory-authorized indoor thermostats with the

2-speed outdoor units, there are 2 locations where system-function LED-indicator lights are available. The indoor thermostat provides indicator lights for high- and low-speed operation, system malfunction, and auxiliary heat for heat pumps. The 2-speed control board has an LED which provides signals for several system operations. See Table 15 for LED functions, indicator locations, and definitions. Table 15 also provides the order of signal importance if more than 1 signal should occur. The signal to the indoor thermostat is supplied by the low-voltage ″L″ lead.

THREE-SECOND TIME DELAY Any time the control receives a 24v input, such as Y1 or Y2, there

is a 3-sec time delay before the control function is initiated. This helps prevent nuisance trips and thermostat ″jiggling.″

ONE-MINUTE SPEED-CHANGE TIME DELAY When the compressor changes speeds from high to low or low to

high, there is a 1-minute time delay before the compressor restarts. The outdoor fan motor remains running.

FIVE-MINUTE TIME DELAY The 2-speed-control logic contains a 5-minute time delay that

prevents the unit from short cycling after a thermostat-off cycle or power interruption. The unit can be forced to operate immediately by momentarily touching a jumper between the speed-up terminals of the control board. (See Fig. 33 and 34.) The speed-up feature will not bypass any other function or time delay.

HIGH VOLTAGE LOW VOLTAGE

L2 LO HI CCH ODF

LED 1

LM1 LM2 DFT1 DFT2 T1 T2 S2 S1 PW2 PW1

P1118

K7K6K5K4K3K2K1

SPEED-UP

STAGE 2

LATCH

FURN INT

OFF ON

DEFROST

TIME

BALANCE

POINT

A93569

Fig. 33—Two-Speed Control Board

TWO-MINUTE LOW-SPEED MINIMUM If the unit has not operated within the past 30 minutes, the unit

operates for a minimum of 2 minutes in low speed upon the next thermostat high or low demand.

LM1 LM2 DFT1 DFT2 T1 T2 S2 S1 PW2 PW1

P1118

FURN INT

OFF ON

SPEED-UP

ZONE

STAGE 2

LATCH

100

OFF105

DEFROST

TIME

10 15

BALANCE

POINT

4540

A93568

Fig. 34—Speedup Terminals

CRANKCASE-HEATER OPERATION The 2-speed control energizes the crankcase heater during the

unit’s off cycle when the outdoor ambient is below 75°F. OUTDOOR FAN-MOTOR OPERATION The 2-speed control energizes the outdoor fan any time the

compressor is operating. The outdoor fan remains energized during the 1-minute, speed-change time delay and if a pressure switch or compressor PTC overload should trip.

If the outdoor fan motor won’t run, check the header-pin housing. (See Fig. 37.) There should be NO jumper wire between Terminals 15 and 16.

Heat Pumps After the termination of a defrost cycle, the outdoor fan delays

come on for 20 sec. This allows the refrigeration system to recover the outdoor coil heat and minimize the ″steam cloud″ effect.

SECOND-STAGE LATCHING When low-speed cooling operation no longer satisfies the first

stage of the indoor thermostat, the indoor temperature will increase by 2° until second stage is energized. After high-speed cooling satisfies second stage, it returns to low-speed cooling operation. If desired, the installer may select to have high-speed cooling by energizing Y1. High speed will stay energized until Y1 is satisfied. This eliminates the temperature drop between the first and second stages of indoor thermostat, holding room temperature closer to set point.

To utilize this function, the unit capacity should be plotted versus the heat gain of the structure, which provides the system’s balance point when the structure requires high-speed capacity. (See Fig.

35.) Second-stage latching can be selected by rotating the potentiom-

eter (POT) to the desired outdoor second-stage latching temperature (See Fig. 34.) The temperatures that can be selected are 85°, 90°,95°, 100°, and 105°F. The POT is factory set at 105°F.

ZONE SELECTION If the stage–2 latch POT is set to ZONE position, the compressor

operating speed in either heat or cool mode is determined by the Y1 and/or Y2 inputs. The system operates in low speed with a Y1 input and high speed with Y2 or Y1-and-Y2 input. This allows the multistage-zoning system to determine what speed is needed regardless of outdoor temperature or switchover point.

DEFROST TIME SELECTION The defrost interval can be field selected, depending on local or

geographic requirements. It is factory set at 90 minutes and can be changed to either 30 or 50 minutes by rotating the defrost-time POT. (See Fig. 34.)

—31—

TABLE 15—FUNCTION LIGHT CODE AND DISPLAY LOCATION

CODE T’STAT UNIT DEFINITION * POSSIBLE CAUSE

Constant flash

No pause

1 flash

w/pause

2 flashes

w/pause

3 flashes

w/pause

4 flashes

w/pause

3 flashes

pause

4 flashes

5 flashes

w/pause

6 flashes

w/pause†

Constant light

No pause

No flash

*Function light signals order of importance; in case of multiple-signal request, 1 is most important.

†Signal at thermostat will occur after 3 consecutive attempted restarts and lockout has occurred. ‡Will be energized if pressure switch remains open for 1 hr.

**Check both thermistors to determine which is faulty.

— X

— X Low-speed operation 8 —

— X High-speed operation 7 —

X X Ambient thermistor failure 6 —

X X Coil thermistor failure 5 —

X X Thermistor out of range** 4

X‡ X

X X Compressor PTCs out of limit 2

X X Board failure 1

No demand

Stand by

Pressure switch trip

(LM1/LM2)

9 —

Thermistor drift, wrong location

Incorrect wiring

Incorrect refrigerant charge

Dirty indoor/outdoor coil

Dirty outdoor coil

Refrigerant overcharge

Wrong indoor coil

Low refrigerant charge

Compressor mechanical problem

Dirty indoor/outdoor coil

Equipment or electrical service

not grounded

LOW SPEED CAPACITY

BTU (1000'S)

HIGH SPEED CAPACITY

50 60 70 80 90 100 110 120

TEMPERATURE (°F)

HIGH SPEED BALANCE POINT

LOW SPEED BALANCE POINT

STRUCTURE BALANCE POINT

A91282

Fig. 35—Typical Cooling Balance Points

DEFROST The 2-speed control logic for the defrost function is the standard

time and temperature initiated, time or temperature terminated. Defrost occurs only at outdoor temperatures less than 50°F. The control initiates defrost when the outdoor coil thermistor is 30°F(±

2) or less, and the selected defrost time (interval) has been accumulated during unit operation. Termination occurs when the coil thermistor reaches 80°F (± 5) or the defrost period reaches a maximum of 10 minutes.

Defrost always occurs in high speed unless the stage–2 latch POT is set at ZONE. During defrost the unit operates in high speed, energizes the reversing valve (O) and auxiliary heat (W2), and de-energizes the outdoor fan. Upon termination, there is a 20-sec delay in the outdoor fan being energized. If the stage–2 latch POT is set to ZONE and the heat pump is in low speed, it defrosts in low speed.

FIELD-INITIATED FORCED DEFROST By placing a jumper across the speedup terminals for a minimum of 5 sec and then removing it, the unit initiates a defrost cycle. (See Fig. 34.) The cycle occurs only if the outdoor ambient is less than 50°F, regardless of outdoor coil temperature. The cycle terminates when the coil thermistor reaches 80°F(±5)orthedefrost period reaches a maximum of 10 minutes. FURNACE INTERFACE This feature provides a heat-pump lockout upon a demand for auxiliary heat (W2) and must be used when interfacing a heat pump with a gas/oil furnace. Field selection of the furnaceinterface option is done by connecting the factory-supplied jumper to the ON position of the 3 terminal connectors. (See Fig. 33.) When the option is selected, the heat pump will be locked out of operation any time there is a thermostat demand for W2 or the outdoor ambient is below the balance-point POT-setting selection. (See Fig. 34.) When the unit requires defrost, auxiliary heat (W2) energizes the furnace. After defrost is terminated, the heat pump shuts down and the furnace satisfies the thermostat. To utilize this function, the economic and/or thermal balance point must be determined. See the appropriate heat pump balance-point worksheet available from your distributor or branch. BALANCE POINT This feature can be used in 2 different options: furnace interface or electric-heat staging. Refer to the Furnace Interface section for its application. If the heat pump is installed with a fan coil with multistages of electric heat, this option can be used to stage the banks of heat by outdoor ambient. This eliminates the need for accessory outdoor thermostats. When using this option to stage electric heat, first stage is energized by a W2 demand, and second stage is energized by a W3 demand. Select the W3 desired temperature by rotating the balance-point POT. (See Fig. 34.) Temperatures that may be selected are 10°,15°,20°,25°,30°,35°,40°, and 45°F. The POT is factory set at 45°F. LOW-SPEED HEATING WITH AUXILIARY HEAT If the system is operating in low-speed heating and there is a demand for auxiliary heat (W2), the system changes to high-speed operation. W2 is energized unless the low-voltage control wiring is configured as described in Fig. 36.

—32—

TWO SPEED

THERMOSTAT

FAN

COIL

W2 W3

TWO SPEED HEAT PUMP

CONTROL LOGIC

PRESSURE SWITCH PROTECTION The outdoor unit is equipped with high- and low-pressure

switches, wired in series. If a pressure switch opens, the control provides a 5-minute time delay in outdoor unit operation with the outdoor fan running. A malfunction signal appears on the control when a pressure switch opens. If the switch remains open for 1 hr or longer, a malfunction signal is provided at the L terminal of the

A93572

Fig. 36—Low-Voltage Control Wiring

AUXILIARY HEAT (W2) LOCKOUT In some areas, it is necessary to disable the auxiliary heat, except

for defrost, until the outdoor ambient is less than the structure’s balance point. This is accomplished by using the low-voltage wiring as shown in Fig. 36. Wire the 24vac W2 signal from the indoor thermostat to W3 of the control, and W2 of the control to W2 of the indoor unit. When the outdoor ambient is less than the setting of the balance-point POT, the 24vac signal energizes the auxiliary heat (W2) of the indoor unit.

EMERGENCY HEAT If the 2-speed control receives a call for auxiliary heat (W2)

without a heat-pump heating (Y1) call, the second auxiliary stage (W3) is energized. This ensures all available heat is energized if the indoor thermostat is switched to emergency heat.

COMPRESSOR PTC-OVERLOAD PROTECTION The control senses the resistance of the compressor internal

positive-temperature coefficient (PTC) overloads. If the resistance of the PTCs is out of range, the control shuts off the unit until the resistance range is acceptable. See Table 16 for compressor PTC ranges.

TABLE 16—COMPRESSOR PTC RANGES

COMPRESSOR INTERNAL-PTC RESISTANCE

Safe Range (77°F) 1.5k to 7.8k ohms

To trip 26k to 34k ohms

To reset 8.4k to 10k ohms

When the control turns off the outdoor unit due to out-of-range PTCs, the unit remains off for 15 minutes with the outdoor fan running. After 15 minutes, the control checks the resistance every 5 minutes until it reaches the reset range. During this time, a malfunction signal appears on the control board. If this happens, remove the wires on control board at S1 and S2 and measure the resistance across the leads. When the resistance reaches 8,400 to 10,000 ohms, system operation may be resumed. If the resistance remains outside this range, a quick check of the leads at the compressor should be made. Loose connections can cause inaccurate readings. If a PTC trip occurs 3 times, the control will lock out the outdoor-unit operation and provide malfunction signals at both the control and indoor thermostat.

indoor thermostat.

III. FACTORY DEFAULTS

Factory defaults have been provided in the event of failure of the ambient thermistor, outdoor-coil thermistor, and/or furnace interface jumper. Refer to Table 17 for default and function.

IV. MAJOR COMPONENTS

TWO-SPEED CONTROL The 2-speed control board controls the following functions:

• High- and low-compressor contactor operation

• Outdoor fan-motor operation

• Crankcase-heater operation

• Compressor protection

• Pressure-switch monitoring

• Second-stage latching

• Time delays

• 5-minute time-delay speedup (bypass)

Heat pumps:

• Time/temperature defrost

• Defrost-interval selection

• Furnace interface

• Electric-heat staging

HEADER-PIN HOUSING The header-pin housing is the plastic assembly which holds the

stripped-lead ends for field connections. The 2-speed control receives the 24vac low-voltage control-system inputs through the housing/pins. The housing also contains jumpers which the control uses for system configuration, such as heat pump versus air conditioner. See Fig. 37 for header-pin housing configurations.

TWO-SPEED COMPRESSOR The 2-speed compressor contains motor windings that provide

low-speed, 4–pole (1750 rpm) and high-speed, 2–pole (3500 rpm) operation. Refer to Fig. 38 to determine which windings are energized at each speed. Refer to Compressor Winding-Check section under Troubleshooting and Table 18 for appropriate winding resistances.

The 2-speed compressor is also protected by an internal-pressure relief (IPR), which relieves discharge gas into the compressor shell (low side) when the differential between suction and discharge

TABLE 17—FACTORY DEFAULTS

FAILED COMPONENT FUNCTION DEFAULT

Crankcase Heater Energized during any off cycle

Second-Stage Latching Does not function

Furnace Interface

Ambient Thermistor

Outdoor Coil Thermistor Defrost Initiation and Termination

Furnace Interface Jumper Furnace Interface Does not function

Heating Switchover Speed Point

Defrost Initiation

Outdoor Thermostat for

Auxiliary Heat

Balance point does not function, but

interface still energizes furnace and

locks out heat pump with a call for W2

Unit only runs in high-

Defrost is initiated based on coil

Anytime there is a call for W2,

W3 is also energized.

Defrost occurs at each time interval,

but terminates after 5 minutes

compressor speed

temperature only

—33—

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

C - TRANSFORMER COMMON R - TRANSFORMER LINE

W2 - FIRST STAGE AUXILIARY HEAT O - REVERSING VALVE Y2 - SECOND STAGE COOLING/HEAT PUMP Y1 - FIRST STAGE COOLING/HEAT PUMP W3 - SECOND STAGE AUXILIARY HEAT L - MALFUNCTION LIGHT

4 - TON

5 - TON

JUMPER FOR HEAT PUMP ONLY

IF NO JUMPER IS INSTALLED, DEFAULT IS 3 - TON

Fig. 37—Header-Pin Housing

pressures exceeds 500 psi. The compressor is also protected by 3 PTC devices attached to the motor windings. The PTC’s resistance is sensed by the 2-speed control board. See Table 16 for resistance ranges.

MECHANICALLY INTERLOCKED CONTACTORS The 2-speed products are equipped with mechanically interlocked

contactors. Each contactor has interconnecting linkage, providing independent interlocks.

The 2-speed control provides the electrical interlock. The contactors are supplied with 240v coils, which reduce the va requirements of the low-voltage (24vac) control system.

TEMPERATURE THERMISTORS Thermistors are electronic devices which sense temperature. As

the temperature increases, the resistance decreases. Two thermistors are used to sense temperature: one senses outdoor ambient, and the other senses coil temperature (heat pump only). Refer to Fig. 39 for resistance values versus temperature.

If the outdoor ambient thermistor should fail, a malfunction signal appears on the indoor thermostat and 2-speed control. The control does not initiate second-stage latching, crankcase heater is turned on during all off-cycles, heating defaults to high speed, and defrost initiates on demand from coil thermistor. (See Table 17.)

A93576

THERMISTOR CURVE

T3 T8 T7 T2 T1

EXTERNAL MAIN

MAIN WINDING

4 POLE START

2 POLE START

HIGH SPEED

(L1) T1 + T7 (L2) T2 + T3

LOW SPEED

(L1) T1

(L2) T7 + T8

A92015

Fig. 38—Energizing Windings

TABLE 18—TWO-SPEED COMPRESSOR

(WINDING RESISTANCE AT 70°F±2°)

WINDING 3 TON 4 TON 5 TON

T1-T2 0.80 0.70 0.60 T1-T3 3.20 2.20 1.80 T1-T7 1.30 1.00 1.00 T1-T8 3.10 2.20 2.00

90 80

70 60 50 40 30 20

RESISTANCE (KOHMS)

0 20 40 60 80 100 120

TEMPERATURE (DEG. F)

A91431

Fig. 39—Resistance Values Versus Temperature

If the outdoor coil thermistor should fail, a malfunction signal appears on the indoor thermostat and 2-speed control. The control defrosts every 90 minutes of heating operation and terminates in 5 minutes. (See Table 17.)

V. LED FUNCTION/MALFUNCTION LIGHTS

The 2-speed control is equipped with an LED function/ malfunction light.

NOTE: Only malfunction signal appears at thermostat. Both function and malfunction signals appear at control board. (See Fig. 33 for LED location.) Table 15 provides the function/malfunction code, location, and definition.

VI. TROUBLESHOOTING NOTE: Troubleshooting charts for air conditioning and heat

pump units are provided in the back of this manual — see Fig. 52, 53, and 54.

COMPRESSOR WINDING CHECK The 2-speed compressor is nothing more than 2 single-phase

motors within 1 compressor shell. When the compressor fails to start or run, there are 3 tests that can be made: open, ground, or short. This compressor has no internal line-break overload; however, it does have PTC motor protectors. See Compressor PTCOverload Protection section for PTC overload information.

—34—

NOTE: To ensure accurate ohm measurements, place ohmmeter probes on flat surface of compressor-terminal tabs, not the brass mounting screw.

Open To determine if a winding has an actual break in the internal wires

and current is unable to pass through:

1. Be sure all power is off.

2. Discharge all capacitors.

3. Remove wires from terminals T1, T2, T3, T7, and T8.

4. Use an ohmmeter on 0-1000 ohm scale to check resistance. (See Fig. 38, 40, and 41 and Table 18.)

Because winding resistances are usually less than 10 ohm, each reading will appear to be approximately zero ohm. If during any check the resistance remains at 1000 ohm, an open or break exists, and the motor or compressor should be replaced.

Ground To determine if any wire has broken and come in direct contact

with the housing or shell, causing a direct short to ground:

1. Be sure all power is off.

2. Discharge all capacitors.

3. Remove wires from T1, T2, T3, T7, and T8.

4. Allow crankcase heater to remain on for several hrs before checking motor to ensure that windings are not saturated with refrigerant.

5. Using an ohmmeter on R X 10,000 ohm scale, place 1 meter probe on ″ground″ motor or compressor frame. Make a good metal-to-metal contact. Place other probe on terminals T1, T2, T3, T7, and T8 in sequence. Note meter scale.

If any reading of zero or low resistance is obtained, the motor is grounding. Replace the compressor.

Short NOTE: This is an extremely critical test and is not advised unless

the following conditions are met. The correct motor-winding resistances must be known before

testing. See Table 18 for cold-motor winding resistance. The temperature of the windings must be specified, 70°F±2°F. The resistance-measuring instrument must have an accurate ohm-

meter (such as a Wheatstone bridge or null balance-type instrument).

The motor must be dry or free from direct contact with liquid refrigerant.

To determine if any wires have broken through their insulation and come in direct contact with each other, thereby ″shorting″ all or part of the winding(s):

1. Be sure all power is off.

2. Discharge all capacitors.

3. Remove wires from terminals T1, T2, T3, T7, and T8.

4. Subtract instrument probe and lead resistance from each reading. If any reading is within ± 20 percent of the known resistance from Table 18, the motor probably does not have a short. Usually a considerable difference will be noted if a turn-to-turn short is present.

CONTROL BOARD FAILURE The control board continuously monitors its own operation and the

operation of the system. The diagnostic feature allows easy troubleshooting of the control and system in the field. If a failure occurs, the LED light on the control will flash a failure code. If the failure is internal to the control board, the light will stay on continuously (no flash). Before replacing control board, reset the

24v power. If the fault clears, check to ensure the indoor and outdoor unit and electrical service are properly grounded. If the entire system is grounded, the control board should be replaced, as the control is not field reparable. If the control-board light is flashing, see LED and Table 15 for function/malfunction definition. Cycling 24 vac to control board resets previous error messages and any lockouts which have occurred. See Table 19 for more information regarding control-board operation.

CONTROL-BOARD POWER INPUTS AND OUTPUTS See Fig. 33 and 37 for inputs and outputs. BLEED RESISTOR The bleed resistor is a 150k, 2–watt resistor across the compressor-

run capacitor to protect service technician from injury by electrical shock. Capacitor will bleed-off approximately 1 minute after power to outdoor unit is turned off. If run capacitor is changed out, be sure to place bleed resistor on new capacitor. If bleed resistor is damaged, replace resistor.

START CAPACITOR AND RELAY The 2-speed system has a second start relay in the control box. One

start relay is for low-speed start, and the second is for high-speed start. Both start relays use a common-start capacitor. When servicing this equipment, be certain system starts in both low- and high-speed operation.

REFRIGERATION SYSTEM

I. REFRIGERATION CYCLE

In a refrigeration system, refrigerant moves heat from one place to another. It is useful to understand flow of refrigerant in a system.

In a straight cooling system, compressed hot gas leaves compressor and enters condensing coil. As gas passes through condenser coil, it rejects heat and condenses into liquid. The liquid leaves condensing unit through liquid line and enters metering device at indoor coil. As it passes through metering device, it becomes a gas-liquid mixture. As it passes through indoor coil, it absorbs heat and refrigerant and is again compressed to a hot gas. The cycle then repeats.

In a heat pump, the basic cycle is the same. (See Fig. 42.) Reversing valve in system decides which coil, indoor or outdoor, becomes evaporator or condenser. It rejects heat into the home after heat is absorbed by outdoor evaporator coil, thus the home is heated.

In cooling cycle, the indoor coil becomes the evaporator. It absorbs heat from the home and rejects it through the outdoor condenser coil, thus the home is cooled.

A unique feature of the heat pump is that metering devices are designed to meter refrigerant in one direction of flow and allow refrigerant to pass unhindered in the other direction. If indoormetering device is metering refrigerant, the outdoor device bypasses refrigerant and vice versa. This allows both coils to serve a dual function.

II. LEAK DETECTION

CAUTION: Always wear safety glasses and gloves

when handling refrigerants.

New installations should be checked for leaks prior to complete charging.

If a system has lost all or most of its charge, system must be pressurized again, up to approximately 150 lb minimum. This can be done by adding refrigerant using normal charging procedures, or it may be pressurized with nitrogen (less expensive than refrigerant). Nitrogen also leaks faster than R-22 and is not absorbed by refrigeration oil. Nitrogen cannot, however, be detected by a leak detector. (See Fig. 43.)

—35—

SCHEMATIC DIAGRAM

(LADDER FORM)

EQUIP

GND

11 21

17 27

CAP

EXT

MAIN

2515

2616

2212

2313

Fig. 40—Low-Speed Windings

MAIN

LOW

START

COMP

HIGH

START

T3T8

HS SR

1424

A91446

EQUIP

GND

11 21

17 27

CAP

SCHEMATIC DIAGRAM

(LADDER FORM)

EXT

MAIN

1424

MAINT2

LOW

START

2515

2616

2212

2313

COMP

HIGH

START

T3T8

HS SR

Fig. 41—High-Speed Windings

—36—

A91445

COOLING CYCLE

OUTDOOR FAN

REVERSING VALVE

(ENERGIZED)

In all instances, when a leak is found, system charge must be bled down and leak repaired before final charging and operation. After leak testing or leak is repaired, evacuate system, and recharge with correct refrigerant charge.

INDOOR FAN

STRAINER

(METERING)

HEAT PUMP

ACCESSORY

FILTER DRIER

(DUAL FLOW)

INDOOR COIL

ACCUMULATOR

SUCTION SERVICE

PORT AT SERVICE

VALVE (CLG CYCLE)

SUCTION SERVICE PORT

(BYPASSING)

LIQUID LINE SERVICE PORT AT SERVICE VALVE (CLG CYCLE)

COMP

STRAINER

OUTDOOR

LIQUID LINE PRESSURE SWITCH

COIL

A88400

Fig. 42—Heat Pump Refrigerant-Flow Diagrams

CAUTION: Due to the high pressure of nitrogen, it

should never be used without a pressure regulator on the tank.

Leaks in a system pressurized with refrigerant can be spotted with a leak detector that detects extremely small refrigerant leaks. This discussion assumes that system is pressurized with either all refrigerant or a mixture of nitrogen and refrigerant.

If system has been operating for some time, make first check for a leak visually. Since refrigerant carries a small quantity of oil, traces of oil at any joint or connection are an indication that refrigerant is leaking at that point.

A simple and inexpensive method of testing for leaks is to use soap bubbles. Any solution of water and soap may be used. Soap solution is applied to all joints and connections in system. A small pinhole leak is located by tracing bubbles in soap solution around leak. Use electronic leak detector to check for leaks. This unquestionably is the most efficient and easiest method for checking leaks. There are various types of electronic leak detectors. Generally speaking, they are all portable, and most are lightweight, consisting of a box with several switches and a probe or sniffer. Detector is turned on and probe is passed around all fittings and connections in system. Leak is detected by either a movement of a pointer on detector dial, by a buzzing sound, or a light.

III. BRAZING

When brazing is required in the refrigeration system, certain basics should be followed:

1. Clean joints make the best joints. To clean: a. Remove all oxidation from surfaces to a shiny finish

before brazing.

Fig. 43—Leak Detector

TABLE 19—24V PIN CONNECTION TROUBLESHOOTING

MODE OF OPERATION

18-PIN CONNECTOR

All R-C 2-1 Input 24 Check transformer (secondary)

Low-speed Cooling Y1,0-C 8,6-1 Input 24 Check thermostat

High-speed Cooling Y1, Y2, 0-C 8,7,6-1 Input 24 Check thermostat

Low-speed Heating Y1-C 8-1 Input 24 Check thermostat

High-speed Heating

Defrost

Second Stage of

Auxiliary Heat

Cooling Second-

stage Latching

TERMINAL

DESIGNATION

LOCATION ON

CONTROL BOARD

VOLTAGE

PATH

VOLTAGE

REQUIRED

POSSIBLE SOURCE

OF PROBLEM

Y1-C 8-1 Input 24 Check thermostat Y2-C 7-1 Output 24

Outdoor temperature below speed; change temperature

Y1-C 8-1 Input 24 Check thermostat

Y2, W2, 0-C 7,5,6-1 Output 24

Outdoor temperature below 50°F;

Coil temperature less than 30°F Y1, W2-C 7,5-1 Input 24 Check thermostat W3, Y2-C 9,8-1 Output 24 Check balance-point setting

Y1, Y2, 0-C 8,7,6-1 Input 24

Ambient thermistor failure;

Check second-stage POT

A88401

—37—

SERVICE PORT

STEM

SEAT

FORGED FRONT SEATING VALVE

W/SCHRADER CORE

FIELD

SIDE

A91448

Fig. 44—Service Valves

b. Remove all flux residue with brush and water while

material is still hot.

2. Use ″sil-fos″ or ″phos-copper″ for copper-to-copper only.

No flux is required.

3. Silver solder is used on copper-to-brass, copper-to-steel, or copper-to-copper. Flux is required when using silver solder.

4. Fluxes should be used carefully. Avoid excessive application and do not allow fluxes to enter into the system.

5. Proper brazing temperature of copper is when it is heated to a dull red color.

This section on brazing is not intended to teach a technician how to braze. There are books and classes that teach and refine brazing techniques. The basic points above are listed only as a reminder.

IV. SERVICE VALVES

WARNING: Never attempt to make repairs to existing

service valves. Unit operates under high pressure. Damaged seats and o-rings should not be replaced. Replacement of entire service valve is required. Tampering with damaged valves can cause personal injury or death. Service valve must be replaced by properly trained service technician.

Service valves provide a means for holding original factory charge in outdoor unit prior to hookup to indoor coil. They also contain gage ports for measuring system pressures and provide shutoff convenience for certain types of repairs. (See Fig. 44.)

Two types of service valves are used in outdoor residential equipment. The first type is a front-seating valve, which has a service port that contains a Schrader fitting. The service port is always pressurized after the valve is moved off the front-seat position.

The second type is a combination front-seating/back-seating valve, which has a metal-to-metal seat in both the open and closed positions. When it is fully back-seated, the service port is not

FIELD

SIDE

STEM

SERVICE PORT W/SCHRADER CORE

SEAT

BAR STOCK FRONT SEATING VALVE

A91447

pressurized. To pressurize the service port, this valve must be moved off the back-seating position. This valve does not contain a Schrader fitting. Both types of service valves are designed for sweat connection to the field tubing. The service valves in the outdoor unit come from the factory front-seated. This means that the refrigerant charge is isolated from the line-set connection ports. Some heat pumps are shipped with sweat-adapter tube. This tube must be installed on the liquidservice valve. After connecting the sweat adapter to the liquidservice valve of a heat pump, the valves are ready for brazing. The interconnecting tubing (line set) can be brazed to the service valves using either silver-bearing or non-silver-bearing brazing material. Consult local codes. Before brazing the line set to the valves, the belled ends of the sweat connections on the service valves must be cleaned so that no brass plating remains on either the inside or outside of the bell joint. To prevent damage to the valve and/or cap ″O″ ring, use a wet cloth or other acceptable heat-sinking material on the valve before brazing. To prevent damage to the unit, use a metal barrier between brazing area and unit. After the brazing operation and the refrigerant tubing and evaporator coil have been evacuated, the valve stem can be turned counterclockwise until it opens or back-seats, which releases refrigerant into tubing and evaporator coil. The system can now be operated. Back-seating service valves must be back-seated (turned counterclockwise until seated) before the service-port caps can be removed and hoses of gage manifold connected. In this position, refrigerant has access from and through outdoor and indoor unit. The service valve-stem cap is tightened to 20 ± 2 ft/lb torque and the service-port caps to9±2ft/lb torque. The seating surface of the valve stem has a knife-set edge against which the caps are tightened to attain a metal-to-metal seal. If accessory pressure switches are used, the service valve must be cracked. Then, the knife-set stem cap becomes the primary seal. The service valve cannot be field-repaired; therefore, only a complete valve or valve stem and service-port caps are available for replacement.

—38—

PISTON BODY

FEEDER

TUBES

TEFLON SEAL

BRASS HEX BODY

A91138

(ORIENT AS SHOWN)

BRASS

HEX NUT

PISTON

RETAINER

PISTON

STRAINER

Fig. 45—Check-Flo-Rater™ Components

If the service valve is to be replaced, a metal barrier must be inserted between the valve and the unit to prevent damaging the unit exterior from the heat of the brazing operations.

CAUTION: Wear safety glasses and gloves when handling refrigerants.

Pumpdown Procedure Service valves provide a convenient shutoff valve useful for

certain refrigeration-system repairs. System may be pumped down to make repairs on low side without losing complete refrigerant charge.

1. Attach pressure gage to suction service-valve gage port.

2. Front seat liquid-line valve.

3. Start unit in cooling mode. Run until suction pressure reaches 5 psig (35kPa). Do not allow compressor to pump to a vacuum.

4. Shut unit off. Front seat suction valve.

NOTE: All outdoor unit coils will hold only factory-supplied amount of refrigerant. Excess refrigerant, such as in long-line applications, may cause unit to relieve pressure through internal pressure-relief valve (indicated by sudden rise of suction pressure) before suction pressure reaches 5 psig (35kPa). If this occurs, shut off unit immediately, front seat suction valve, and recover remaining pressure.

V. CHECK-FLO-RATER™ (BYPASS-TYPE) HEAT PUMPS ONLY REFRIGERANT-METERING HOLE THROUGH IT. THE RETAINER FORMS A STOP FOR PISTON IN REFRIGERANT-BYPASS MODE AND A SEALING SURFACE FOR LIQUID-LINE FLARE CONNECTION. (SEE FIG. 45.) TO CHECK, CLEAN, OR REPLACE PISTON:

RELIANT PRODUCTS EXCEPT 1992 PRODUCTION

1. Shut off power to unit.

2. Pump unit down using pumpdown procedure described in this service manual.

3. Loosen nut and remove liquid-line flare connection from Check-Flo-Rater™.

4. Pull retainer out of body, being careful not to scratch flare-sealing surface. If retainer does not pull out easily, carefully use locking pliers to remove it.

PISTON

PISTON RETAINER

FLARE ADAPTER

INTERNAL STRAINER

PRODUCTION EXCEPT 1992

A94004

5. Slide piston out by inserting a small, soft wire with small kinks through metering hole. Do not damage metering hole, sealing surface around piston cones, or fluted portion of piston.

6. Clean piston refrigerant-metering hole.

7. Install a new retainer O-ring or retainer assembly before reassembling bypass-type Check-Flo-Rater™.

RELIANT AND CUBE PRODUCTS PRODUCED IN 1992

1. Shut off power to unit.

2. Reclaim outdoor-unit refrigerant.

3. Loosen brass hex nut and remove line from brass hex body.

4. Slide piston out by inserting a small, soft wire with small kinks through metering hole. Do not damage metering hole, sealing surface around piston cones, or fluted portion of piston.

5. Clean piston refrigerant-metering hole.

6. Always replace Teflon seal with new seal. Never try to reuse old seals.

7. Reassemble brass nut and brass hex body. Be sure orientation is as shown in Fig. 45.

VI. REVERSING VALVE

In heat pumps, changeover between heating and cooling modes is accomplished with a valve that reverses flow of refrigerant in system. (See Fig. 46.) This reversing-valve device is easy to troubleshoot and replace. The reversing-valve solenoid can be checked with power off with an ohmmeter. Check for continuity and shorting to ground. With control-circuit (24v) power on, check for correct voltage at solenoid coil. Check for overheated solenoid. With unit operating, other items can be checked, such as frost or condensate water on refrigerant lines. The sound made by a reversing valve as it begins or ends defrost is a ″whooshing″ sound, as the valve reverses and pressures in system equalize. An experienced service technician detects this sound and uses it as a valuable troubleshooting tool. Using a remote measuring device, check inlet and outlet line temperatures. DO NOT touch lines. If reversing valve is operating normally, inlet and outlet temperatures on appropriate lines should be close. Any difference would be due to heat loss or gain across valve body. Temperatures are best checked with a remote-reading, electronic-type thermometer with multiple probes. Route thermocouple leads to inside of coil area through service-valve mountingplate area underneath coil. Fig. 47 and 48 show test points (TP) on reversing valve for recording temperatures. Insulate points for more accurate reading.

—39—

4TH PORT

4 PORT DESIGN

NEW SOLENOID COIL

3 PORT DESIGN

A91457

If valve is defective:

1. Shut off all power to unit and remove all charge from system.

2. Check valve design. If valve is of the 3-port design and new replacement is of the 4-port design, replacement of the solenoid coil and wire leads is necessary. Valve bodies are interchangeable, but solenoid and wires are not. Three-port reversing valve and solenoid coil with leads must be used together. New solenoid coil cannot be used on a 3-port valve. Four-port reversing valve uses solenoid with quick-connect terminals for leads connection. Old solenoid coil cannot be used on 4-port reversing valve. If for any reason a new wire cord is not available, cut the leads on the old solenoid coil as close to the coil as possible. Terminate the leads with 2 female 1/4-in. quick-connects. Connect terminals to new solenoid and tape connection to insulate and provide moisture barrier. Replace these wires as soon as wire cord is available. See RCD (Replacement Component Catalog) for proper cord part number.

3. Remove solenoid coil from valve body. Remove valve by cutting it from system with tubing cutter. Repair person should cut in such a way that stubs can be easily rebrazed back into system. Do not use hacksaw. This introduces chips into system that cause failure. After defective valve is removed, wrap it in wet rag and carefully unbraze stubs. Save stubs for future use. Because defective valve is not overheated, it can be analyzed for cause of failure when it is returned.

4. Braze new valve onto used stubs. Keep stubs oriented correctly. Scratch corresponding matching marks on old valve and stubs and on new valve body to aid in lining up new valve properly. When brazing stubs into valve, protect valve body with wet rag to prevent overheating.

A91456

Fig. 46—Reversing Valve

5. Use slip couplings to install new valve with stubs back into

6. After valve is brazed in, check for leaks. Evacuate and

TO OUTDOOR COIL

Fig. 47—Reversing Valve (Cooling Mode or Defrost

VII. THERMOSTATIC-EXPANSION VALVES (TXV)

The types of TXVs used in condensing-unit and heat-pump systems are as follows:

Rapid-Pressure Balance (RPB)—Has a special bleed port that allows rapid bleed-through of pressure after system shutdown until pressure equalization occurs within approximately 1 to 2 minutes.

system. Even if stubs are long, wrap valve with a wet rag to prevent overheating.

charge system. Operate system in both modes several times to be sure valve functions properly.

FROM INDOOR COIL VIA SERVICE VALVE ON OUTDOOR COIL

TP-2

A88342

TP-4

FROM COMPRESSOR DISCHARGE LINE

TO ACCUMULATOR

TP-3

TP-1

Mode, Solenoid Energized)

—40—

TABLE 20—TXV SUPERHEAT SETTING AT OUTLET OF EVAPORATOR COIL

INSTALLATION TXV TYPE PRODUCT USAGE SUPERHEAT SETTING

Field Accessory RPB/HSO Air Conditioner Indoor Unit 10° Field Accessory RPB/HSO Heat Pump Indoor Unit 6°

Field Accessory/Factory-Installed HSO Indoor Fan Coil Unit 6°

Factory-Installed HSO 2-Speed Heat Pump Outdoor Unit 4°

Factory-Shipped/Field-Installed HSO 2-Speed Indoor Unit 4°

FROM OUTDOOR COIL

TP-4

INSULATE FOR

ACCURATE

READING

FROM COMPRESSOR

DISCHARGE LINE

ACCUMULATOR

INSULATE

TP-3

ACCURATE

READING

TP-1

ELECTRONIC

THERMOMETER

TO INDOOR COIL

VIA SERVICE VALVE

ON OUTDOOR COIL

FOR

TP-2

A88341

Fig. 48—Reversing Valve (Heating Mode, Solenoid De-

Energized)

Hard Shutoff (HSO)—Has no bleed port and allows no bleedthrough after system shutdown. No pressure equalization occurs. Because of unequalized system pressures, a start capacitor and relay must be installed on single-phase reciprocating compressors to start the compressor.

See Table 20 for TXV superheat settings. These settings are factory set and are not field adjustable. Table 17 settings are for Bryant-approved accessories and factory-installed TXVs only.

VIII. THERMOSTATIC-EXPANSION VALVE (BI-FLOW TXV)

The standard TXV is a metering device that is used in condensing and heat pump systems to adjust to changing load conditions by maintaining a preset superheat temperature at the outlet of the evaporator coil. The volume of refrigerant metered through the valve seat is dependent upon:

1. Superheat temperature sensed by cap-tube sensing bulb on suction tube at outlet of evaporator coil. As long as this bulb and cap tube contains some liquid refrigerant, this temperature is converted into suction pressure pushing downward on the diaphragm, which tends to open the valve via the pushrods.

2. The suction pressure at the outlet of the evaporator coil is transferred via the external equalizer tube to the underside of the diaphragm.

3. The needle valve on the pin Bryant is spring-loaded, which also exerts pressure on the underside of the diaphragm via the pushrods, which tends to close the valve. Therefore, bulb pressure equals evaporator pressure (at outlet of coil) plus spring pressure. If the load increases, the temperature increases at the bulb, which increases the pressure on the topside of the diaphragm, which pushes the pin Bryant away from the seat, opening the valve and increasing the flow of refrigerant. The increased refrigerant flow causes

increased leaving evaporator pressure, which is transferred via the equalizer tube to the underside of the diaphragm. This tends to cause the pin-Bryant spring pressure to close the valve. The refrigerant flow is effectively stabilized to the load demand with negligible change in superheat. The bi-flow TXV is used on split-system heat pumps. In the cooling mode, the TXV operates the same as the standard TXV previously explained. (See Fig. 49.) However, when the system is switched to the heating mode of operation, the refrigerant flow is reversed. The bi-flow TXV has an additional internal-check valve and external tubing. (See Fig. 50.) These additions allow the refrigerant to bypass the TXV when refrigerant flow is reversed with only a 1- to 2-psig pressure drop through the device. When the heat pump switches to the defrost mode, the refrigerant flows through a completely open (unthrottled) TXV, and the bulb senses the residual heat of the outlet tube of the coil that had been operating in the heating mode (about 85°F and 155 psig). This temporary, unthrottled valve decreases the indoor-pressure drop, which in turn increases the refrigerant-flow rate, decreases overall defrost time, and enhances defrost efficiency.

IX. COIL REMOVAL

Coils on this family of units are easy to remove, if required for compressor removal or replacement coil.

CAUTION: Wear safety glasses and gloves when handling refrigerants.

To remove or replace coil:

1. Shut off all power to unit.

2. Remove and recover refrigerant from system through service valves.

3. Remove top cover. (See Remove Top Cover section.)

4. Remove screws in base pan to coil grille.

5. Remove coil grille from unit.

6. Remove screws on corner-post (Reliant) service-valve panel (Cube unit) holding coil-tube sheet.

CAUTION: Cut tubes to reduce the possibility of fire and personal injury.

7. Use midget-tubing cutter to cut liquid and vapor lines at both sides of coil. Cut in convenient location for easy reassembly with copper-slip couplings.

8. Lift coil vertically from basepan. Place aside carefully.

9. Reverse procedure to reinstall coil.

X. LIQUID-LINE STRAINER (HEAT PUMPS ONLY)

The liquid-line strainer is upstream of the heating piston. The strainer catches debris in the liquid line during heating mode. If it becomes plugged, system operation and pressure become abnormal, and the compressor may become hot and cycle off on the overloads or pressure relief.

—41—

INLET

DIAPHRAGM

BYPASS TXV

PUSHRODS

FEEDER TUBES

OUTLET

NEEDLE VALVE

SPRING

DISTRIBUTOR

CHECK VALVE

(CLOSED)

CAPILLARY TUBE

COIL

BULB

INLET

DIAPHRAGM

BYPASS TXV

BYPASS TUBE

PUSHRODS

FEEDER TUBES

OUTLET

NEEDLE VALVE

SPRING

DISTRIBUTOR

EXTERNAL EQUALIZER TUBE

A88406

Fig. 49—TXV in Cooling Mode

CAPILLARY TUBE

COIL

BULB

CHECK VALVE

(OPEN)

BYPASS TUBE

EXTERNAL EQUALIZER TUBE

A88405

Fig. 50—TXV in Heating Mode

—42—

If the strainer must be replaced, shut off all power to the unit. See Fig. 49 for strainer location.

XI. ACCUMULATOR

The accumulator is a device always found in heat pumps and found in some condensing-unit models. Under some light-load conditions on indoor coils and on outdoor coil with heat pump in heating mode, some liquid refrigerant is present in suction gas returning to compressor. The accumulator stores liquid and allows it to boil off into a vapor so it can be safely returned to compressor. Since a compressor is designed to pump refrigerant in its gaseous state, introduction of liquid into it could cause severe damage or total failure of compressor.

The accumulator is a passive device which seldom needs replacing. Occasionally, its internal oil-return orifice or bleed hole may become plugged. Some oil is contained in refrigerant returning to compressor. It cannot boil off in accumulator with liquid refrigerant. The bleed hole allows a small amount of oil and refrigerant to enter the return line where velocity of refrigerant returns it to compressor. If bleed hole plugs, oil is trapped in accumulator, and compressor will eventually fail from lack of lubrication. If bleed hole is plugged, accumulator must be changed. Bleed hole is so tiny that cleaning efforts are usually not successful. The accumulator has a fusible element located in the bottom-end bell. (See Fig.

51.) This fusible element melts at 430°F and vents the refrigerant, if this temperature is reached either internal or external to the system. If fuse melts, the accumulator must be replaced.

To change accumulator:

1. Shut off all power to unit.

2. Remove and reclaim all refrigerant from system.

NOTE: Coil may be removed for access to accumulator. Refer to appropriate sections of service manual for instructions.

CAUTION: Wear safety glasses and gloves when working on refrigerants and when using brazing torch.

3. When accumulator is exposed, remove it from system with tubing cutter.

4. Scratch matching marks on tubing stubs and old accumulator. Scratch matching marks on new accumulator. Unbraze stubs from old accumulator and braze into new accumulator.

5. Thoroughly rinse any flux residue from joints and paint with corrosion-resistant coating such as zinc-rich paint.

6. Reinstall accumulator into system with copper-slip couplings.

7. Evacuate and charge system.

8. Pour and measure oil quantity (if any) from old accumulator. If more than 20 percent of oil charge is trapped in accumulator, add oil to compressor to make up for this loss.

XII. CONTAMINANT REMOVAL

Proper evacuation of a unit removes non-condensibles and assures a tight, dry system before charging. The 2 methods used to evacuate a system are the deep-vacuum method and the tripleevacuation method. DEEP-VACUUM METHOD The deep-vacuum method requires a vacuum pump capable of pulling a vacuum of 1000 microns and a vacuum gage capable of accurately measuring this vacuum depth. The deep-vacuum method is the most positive way of assuring a system is free of air and liquid water. TRIPLE-EVACUATION METHOD The triple-evacuation method can be used where the vacuum pump is capable of pumping down to only 28 in. of mercury vacuum, and the system does not contain any liquid water. The procedure is as follows.

430° FUSE ELEMENT

A88410

Fig. 51—Accumulator

1. Pump the system down to 28 in. of mercury vacuum and allow pump to continue to operate for additional 15 minutes.

2. Close service valves and shut off vacuum pump.

3. Connect a refrigerant cylinder to the system and open until system pressure is 2 psig.

4. Close the service valve.

5. Allow system to stand for 1 hr, during which time the dry refrigerant will be able to diffuse throughout the system, absorbing moisture.

This procedure is repeated 3 times, after which the system will be free of any contaminants and water vapor.

XIII. SYSTEM CHARGING

For all approved combinations, system must be charged correctly for normal system operation and reliable operation of components.

CAUTION: Always wear safety glasses and gloves when handling refrigerants.

If system has lost all charge, weigh in charge using dial-a-charge or digital scale.

System charge should be fine-tuned by using the superheat or subcooling method, whichever is appropriate. These methods are covered in the Checking Charge section below.

NOTE: Heat-pump check charts are for checking charge and performance and for adding a small amount of charge. During heating mode, correct method of charging is the weight method. In heating mode, check should be made approximately 15 minutes after a defrost with unit running with a clean coil. In cooling cycle, system should run at least 10 minutes for temperatures and pressures to stabilize. All charts assume there are no system abnormalities and indoor coil airflows are correct. If system abnormalities exist, correct them before checking system charge.

XIV. CHECKING CHARGE

Superheat charging is the process of charging refrigerant into a system until the temperature (superheat) of the suction gas entering the compressor reaches a prescribed value. Small variations of charge affect suction-gas superheat temperatures greatly. Therefore, this method of charging is very accurate. This method can be used only on split-system condensing units and heat pumps (operating in the cooling mode) with fixed-restrictor-type metering devices such as Check-Flo-Rater™, cap tube, etc. For units using

—43—

TABLE 21—SUPERHEAT CHARGING TABLE

OUTDOOR TEMP (°F)

55 9 12141720232629323537404245 60 7 10121518212427303335384043 65 — 6 101316192124273033363841 70 ——7 1013161921242730333639 75 ———6 9 12 15 18 21 24 28 31 34 37 80 ————5 8 12 15 18 21 25 28 31 35 85 ——————8 11151922263033 90 ——————5 9 13 16 20 24 27 31

95 ———————6 101418222529 100 ———————— 8 1215202327 105 ———————— 5 9 13 17 22 26 110 ————————— 6 11152025 115 —————————— 8 141823

Where a dash appears, do not attempt to charge system under these conditions or refrigerant slugging may occur.

50 52 54 56 58 60 62 64 66 68 70 72 74 76

INDOOR COIL ENTERING AIR TEMP (°F WET BULB)

TABLE 22—REQUIRED VAPOR TEMPERATURE (°F)

SUPERHEAT TEMP

(°F)

0 35 37 39 41 43 45 47 49 51 2 37 39 41 43 45 47 49 51 53 4 39 41 43 45 47 49 51 53 55 6 41 43 45 47 49 51 53 55 57

8 43 45 47 49 51 53 55 57 59 10 45 47 49 51 53 55 57 59 61 12 47 49 51 53 55 57 59 61 63 14 49 51 53 55 57 59 61 63 65 16 51 53 55 57 59 61 63 65 67 18 53 55 57 59 61 63 65 67 69 20 55 57 59 61 63 65 67 69 71 22 57 59 61 63 65 67 69 71 73 24 59 61 63 65 67 69 71 73 75 26 61 63 65 67 69 71 73 75 77 28 63 65 67 69 71 73 75 77 79 30 65 67 69 71 73 75 77 79 81 32 67 69 71 73 75 77 79 81 83 34 69 71 73 75 77 79 81 83 85 36 71 73 75 77 79 81 83 85 87 38 73 75 77 79 81 83 85 87 89 40 75 77 79 81 83 85 87 89 91

61.5 64.2 67.1 70.0 73.0 76.0 79.2 82.4 85.7

VAPOR PRESSURE AT SERVICE PORT (PSIG)

a TXV, the subcooling method must be used. Heat pumps must be operating in the cooling mode. To charge by superheat, a service technician needs an accurate superheat thermocouple or thermistor-type thermometer, a sling psychrometer, and a gage manifold. Do not use mercury or small-dial-type thermometers as they are not adequate for this type of measurement. Then use 1 of the following procedures:

SUPERHEAT CHARGING METHOD

1. Operate a unit a minimum of 10 minutes before checking charge.

2. Measure vapor pressure by attaching a gage to vapor valve-service port.

3. Measure vapor-line temperature by attaching a service thermometer to unit vapor line near vapor valve. On a heat pump, attach to the suction tube between the accumulator and the compressor. Insulate thermometer for accurate readings.

4. Measure outdoor-air, dry-bulb temperature with a second thermometer.

5. Measure indoor-air (entering indoor coil), wet-bulb temperature with a sling psychrometer.

6. Locate outdoor temperature and evaporator entering air wet-bulb temperature in Table 21. At this intersection note the superheat.

7. Locate superheat temperature located in previous step and vapor pressure in Table 22. At this intersection note vapor-line temperature.

8. If unit has a higher vapor-line temperature than charted temperature, add refrigerant until charted temperature is reached.

9. If unit has a lower vapor-line temperature than charted temperature, bleed refrigerant until charted temperature is reached.

10. If outdoor-air temperature or pressure at vapor valve changes, charge to new vapor-line temperature indicated on chart.

SUBCOOLING CHARGING METHOD

1. Operate unit a minimum of 15 minutes before checking charge.

—44—

TABLE 23—SUBCOOLING AT LIQUID-SERVICE VALVE FOR UNITS PRODUCED THROUGH DECEMBER, 1992

RELIANT AIR CONDITIONERS

598A

Model 590A 591A/592A 593A/594A 593B 593C 594C 595A 596A 597A 597B

Series ABCABCDABCDABABABAAAAAA

014 14 14 — 14 14 14 — 66—————————————— 018 17 17 — 14 14 14 — 77——11 — 99—— 98———— 024 13 13 — 17 17 17 — 88——13 — 16 21 12 — 13 12 11 13 —— 030 15 15 — 91010— 6 6 10 13 11 — 15 15 14 — 10 9 10 11 —— 036 13 12 — 16 16 16 — 12 12 5 — 9 — 13 12 16 — 14 13 12 14 12 9 038 ———————————16 ——————————— 042 13 13 14 16 19 19 15 12 12 ——11 — 13 — 21 — 11 11 15 15 —— 048 15 14 — 18 14 18 — 14 14 ——18 — 17 — 14 — 10 10 11 11 12 9 060 19 22 — 18 18 18 — 14 14 ——11 — 16 — 19 —— — 12 11 12 9

RELIANT HEAT PUMPS

698A

Model 690A 691A/692A 693A/694A 693B 693C 694C 697A 697B

Series ABCDABABA A A A AAAAA

014 777—————— — — — ————— 018 18 18 18 — 16 16 11 11 10 9 7 9 10 ———— 024 18 18 18 — 16 16 11 11 13 6 5 11 11 ———— 030 13 13 13 — 20 20 10 10 11 10 10 9 10 ———— 036 18 18 18 — 14 14 10 10 11 13 12 9 10 12 7 18 15 042 13 11 11 — 18 18 15 15 12 10 12 11 12 ———— 048 22 17 15 14 19 14 13 13 — 15 12 10 11 14 9 25 18 060 23 23 23 — 13 13 14 14 — 15 10 12 7 14 9 22 21

Cooling Heating

High Low High Low

High

598A

Low

MODEL

Series ABABCDA

014 ————10 —— 018 15 16 11 14 12 — 17 024 14 11 14 8 —— 19 030 12 12 9 10 — 12 — 036 18 16 11 7 —— — 042 18 17 7 ———— 048 — 17 12 ———— 060 — 21 10 ———

2. Measure liquid service-valve pressure by attaching an accurate gage to the service port.

3. Measure the liquid-line temperature by attaching an accurate thermistor-type or electronic thermometer to the liquid line near the outdoor coil.

4. Refer to unit-rating plate to find required subcooling temperature for units produced during or after January

1993. For units produced through December 1992, refer to

CUBE UNIT—AIR CONDITIONERS CUBE UNIT—HEAT PUMPS HORIZONTAL AIR CONDITIONERS

561A/571A 661A/671A 566D 566E

cally on this equipment. The frequency with which maintenance is performed is dependent on such factors as hours of operation, geographic location, and local environmental conditions.

WARNING: Disconnect all electrical power to unit before performing any maintenance or service on outdoor unit. Remember to disconnect power supply to air handler as this unit supplies low-voltage power to the outdoor unit. Electric shock can cause personal injury or death.

Table 23. Find the point at which the required subcooling temperature intersects the measured liquid service-valve pressure on Table 24.

5. To obtain the required subcooling temperature at a specific liquid-line pressure, add refrigerant if liquid-line temperature is higher than indicated or remove refrigerant if temperature is lower. Allow a tolerance of 3°F.

CARE AND MAINTENANCE

To assure high performance and minimize possible equipment malfunction, it is essential that maintenance be performed periodi-

The minimum maintenance that should be performed on this equipment is as follows.

1. Check outdoor coil for cleanliness each month during the heating (heat pump only) or cooling season and clean as necessary, but clean at least once each heating (heat pump only) and cooling season.

2. Check fan motor and blade for cleanliness each heating and cooling season and clean as necessary.

—45—

PRESSURE (PSIG)

AT SERVICE FITTING

134 76 71 66 61 56 51 141 79 74 69 64 59 54 148 82 77 72 67 62 57 156 85 80 75 70 65 60 163 88 83 78 73 68 63 171 91 86 81 76 71 66 179 94 89 84 79 74 69 187 97 92 87 82 77 72 196 100 95 90 85 80 75 205 103 98 93 88 83 78 214 106 101 96 91 86 81 223 109 104 99 94 89 84 233 112 107 102 97 92 87 243 115 110 105 100 95 90 253 118 113 108 103 98 93 264 121 116 111 106 101 96 274 124 119 114 109 104 99 285 127 122 117 112 107 102 297 130 125 120 115 110 105 309 133 128 123 118 113 108 321 136 131 126 121 116 111 331 139 134 129 124 119 114 346 142 137 132 127 122 117 359 145 140 135 130 125 120

TABLE 24—REQUIRED LIQUID-LINE TEMPERATURE

REQUIRED SUBCOOLING TEMPERATURE (°F)

0 5 10 15 20 25

3. Check electrical connections for tightness and controls for proper operation each heating (heat pump only) or cooling season and service as necessary.

CAUTION: Because of possible damage to the equipment or personal injury, maintenance should be performed by qualified personnel only.

COIL CLEANING

1. Remove top cover. See Remove Top Cover section.

CAUTION: Coil fin damage can result in higher operating costs or compressor damage. Do not use flame, high-pressure water, steam, or volatile or corrosive cleaners on fins or tubing.

2. Clean coil using vacuum cleaner and its crevice tool. Move crevice tool vertically, close to area being cleaned, making sure tool touches only the dirt on the fins and not the fins. To prevent fin damage, do not scrub fins with tool or move tool horizontally against fins.

3. If oil deposits are present, spray coil with ordinary household detergent. Wait 10 minutes, and proceed to next step.

4. Using garden hose, spray coil vertically downward with constant stream of water at moderate pressure. Keep nozzle ata15° to 20° angle, about 3 in. from coil face and 18 in. from tube. Spray so debris is washed out of coil and basepan.

5. Restore power to unit.

CLEANING OUTDOOR FAN MOTOR AND BLADE

1. Remove fan motor and blade. Refer to Remove Fan-Motor Assembly section of this manual. Be careful not to bend or dent fan blade.

2. Clean motor and blade with soft brush or cloth. Be careful not to disturb balance weights on fan blade.

3. Check fan-blade setscrew for tightness.

4. Reinstall fan motor and blade to top cover and check for alignment.

5. Reinstall top cover and position blade as per Fig. 24.

6. Reconnect electrical power and check for proper operation.

ELECTRICAL CONTROLS AND WIRING

1. Disconnect power to both the outdoor and indoor units.

2. Check all electrical connections for tightness. Tighten all screws on electrical connections. If any connections appear to be burned or smoky, disassemble the connection, clean all parts and stripped wires, and reassemble. Use a new connector if old one is burned or corroded and crimp tightly.

3. Reconnect electrical power to the indoor and outdoor units and observe unit through 1 complete operating cycle.

4. If there are any discrepancies in the operating cycle, troubleshoot to find the cause, and correct.

REFRIGERANT CIRCUIT

1. Check the refrigerant charge using the superheat or subcooling method, whichever is applicable. If low on charge, check unit for leaks using an electronic leak detector.

2. If any leaks are found, recover or isolate charge (pumpdown) if applicable and make necessary repairs.

3. Evacuate, recharge, and operate unit through entire cycle.

FINAL CHECKOUT After the unit has been operating, the following items should be

checked:

1. Check that unit operational noise is not excessive due to vibration of components, tubing, panels, etc. If present, isolate problem and correct.

2. Check to be sure caps are installed on service valves and that they are tight.

—46—

3. Check to be sure tools, loose parts, and debris are removed from the unit.

4. Check to be sure all panels and screws are in place and tight.

Desert and Seacoast Locations Special consideration must be given to the installation and main-

tenance of condensing units and heat pumps installed in seacoast or desert locations. Salt and the alkali content of the sand adhere to the aluminum fins of the coil and can cause premature coil failure due to corrosion.

Preventive measures can be taken during installations, such as:

1. Locating the unit on side of structure opposite the prevailing winds.

2. Elevating the unit to height where drifting sand cannot pile up against coil. Four-in.-high mounting feet or an 18-in.high mounting rack are available as accessories and can be used to elevate the unit.

3. Addition of coastal filter (see pre-sale literature for accessory listing).

Special maintenance requirements are as follows:

1. Frequent inspection of coil and base pan, especially after storms and/or high winds.

2. Cleaning coil by flushing out sand from between coil fins and out of base pan as frequently as inspection determines necessary.

3. Protecting the unit in ″off season″ with cover that allows air to circulate through but prevents sand from sifting in (such as canvas material). Do not use plastic as plastic will hold moisture.

—47—

AIR CONDITIONER

TROUBLESHOOTING CHART

NO COOLING OR

INSUFFICIENT

COOLING

COMPRESSOR WILL NOT RUN

CONTACTOR

OPEN

POWER SUPPLY

DEFECTIVE

LOW-VOLTAGE

TRANSFORMER

OPEN

THERMOSTAT

OPEN CONTROL

CIRCUIT

LOSS OF CHARGE

CONTACTOR OR COIL DEFECTIVE

CONTACTOR

CLOSED

COMPRESSOR

POWER SUPPLY

OPEN

LOOSE LEADS AT

COMPRESSOR

FAULTY START

GEAR (1-PH)

OPEN SHORTED

OR GROUNDED

COMPRESSOR

MOTOR

WINDINGS

COMPRESSOR

STUCK

COMPRESSOR

INTERNAL

PROTECTION

OPEN

OUTDOOR FAN

STOPPED OR

CYCLING ON

OVERLOAD

OUTDOOR AIR RESTRICTED OR RECIRCULATING

RESTRICTED

DISCHARGE

TUBE

OVERCHARGE

OR NON-

CONDENSABLES

IN SYSTEM

LOW

REFRIGERANT

CHARGE

LINE VOLTAGE

TOO HIGH OR

LOW

DEFECTIVE RUN

CAPACITOR

COMPRESSOR

RUNS BUT

CYCLES ON

INTERNAL

OVERLOAD

LOOSE LEAD

AT FAN MOTOR

MOTOR

DEFECTIVE

INCORRECT

OFM

CAPACITOR

LOW SUCTION

PRESSURE

DIRTY AIR

FILTERS

DUCT

RESTRICTED

DAMPERS

PARTLY CLOSED

INDOOR COIL

FROSTED

SLIGHTLY

LOW ON

REFRIGERANT

LIQUID LINE

SLIGHTLY

RESTRICTED

COMPRESSOR

RUNS BUT

INSUFFICIENT

COOLING

HIGH SUCTION

LOW HEAD PRESSURE

DEFECTIVE

COMPRESSOR

VALVES

INTERNAL

PRESSURE

RELIEF OPEN

HIGH SUCTION

LOW

SUPERHEAT

UNIT

OVERCHARGED

INCORRECT

SIZE

PISTON

LOOSE

ELECTRICAL

CONNECTION

DEFECTIVE RUN

CAPACITOR

COMPRESSOR

BEARINGS

HIGH

SUPERHEAT

PISTON

RESTRICTED

INCORRECT

SIZE

PISTON

INDOOR COIL

STRAINER

RESTRICTED

INDOOR

BLOWER MOTOR

DEFECTIVE OR

CYCLING ON OL

Fig. 52—Air-Conditioner Troubleshooting Chart

A90208

—48—

HEAT PUMP

TROUBLESHOOTING–COOLING CYCLE

NO COOLING OR

INSUFFICIENT

COOLING

COMPRESSOR WILL NOT RUN

CONTACTOR

OPEN

POWER SUPPLY

DEFECTIVE

LOW-VOLTAGE

TRANSFORMER

OPEN

THERMOSTAT

OPEN CONTROL

CIRCUIT

LOSS OF CHARGE

CONTACTOR OR COIL DEFECTIVE

CONTACTOR

CLOSED

COMPRESSOR

POWER SUPPLY

OPEN

LOOSE LEADS AT

COMPRESSOR

FAULTY START

GEAR (1-PH)

OPEN SHORTED

OR GROUNDED

COMPRESSOR

MOTOR

WINDINGS

COMPRESSOR

STUCK

COMPRESSOR

INTERNAL

PROTECTION

OPEN

COMPRESSOR

OUTDOOR FAN

STOPPED OR

CYCLING ON

OVERLOAD

OUTDOOR AIR RESTRICTED OR RECIRCULATING

DAMAGED OR

STUCK

REVERSING

VALVE

RESTRICTED

DISCHARGE

TUBE

OVERCHARGE

OR NON-

CONDENSABLES

IN SYSTEM

LOW

REFRIGERANT

CHARGE

LINE VOLTAGE

TOO HIGH OR

LOW

RUNS BUT

CYCLES ON

INTERNAL

OVERLOAD

LOOSE LEAD

AT FAN MOTOR

DEFROST RELAY

N.C. CONTACTS

OPEN

MOTOR

DEFECTIVE

INCORRECT

OFM

CAPACITOR

DEFECTIVE

DEFROST

THERMOSTAT

LOW SUCTION

PRESSURE

DIRTY AIR

FILTERS

DUCT

RESTRICTED

DAMPERS

PARTLY CLOSED

INDOOR COIL

FROSTED

SLIGHTLY

LOW ON

REFRIGERANT

LIQUID LINE

SLIGHTLY

RESTRICTED

COMPRESSOR

RUNS BUT

INSUFFICIENT

COOLING

HIGH SUCTION

LOW HEAD

PRESSURE

REVERSING

VALVE HUNG UP

OR INTERNAL

LEAK

DEFECTIVE

COMPRESSOR

VALVES

INTERNAL

PRESSURE

RELIEF OPEN

HIGH SUCTION

LOW

SUPERHEAT

UNIT

OVERCHARGED

INCORRECT

SIZE

PISTON

LOOSE

ELECTRICAL

CONNECTION

DEFECTIVE RUN

CAPACITOR

Fig. 53—Heat-Pump Troubleshooting Chart — Cooling Cycle

DEFECTIVE RUN

CAPACITOR

COMPRESSOR

BEARINGS

HIGH

SUPERHEAT

PISTON

RESTRICTED

INCORRECT

SIZE

PISTON

INDOOR COIL

STRAINER

RESTRICTED

INDOOR

BLOWER MOTOR

DEFECTIVE OR

CYCLING ON OL

A90207

—49—

HEAT PUMP

TROUBLESHOOTING–HEATING CYCLE

NO HEATING OR

INSUFFICIENT

HEATING

COMPRESSOR

WILL NOT RUN

CONTACT

OPEN

DEFECTIVE LOW-

VOLTAGE

TRANSFORMER

REMOTE

CONTROL

CENTER

DEFECTIVE

CONTACTOR

COIL OPEN OR

SHORTED

OPEN INDOOR THERMOSTAT

LIQUID-LINE

PRESSURE

SWITCH OPEN

LOSS OF CHARGE

CONTACTOR

CLOSED

COMPRESSOR

POWER SUPPLY

LOOSE LEADS AT

COMPRESSOR

FAULTY START

GEAR (1-PH)

COMPRESSOR

STUCK

COMPRESSOR

INTERNAL

OVERLOAD

OPEN

OPEN SHORTED

OR GROUNDED

COMPRESSOR

WINDINGS

COMPRESSOR

DIRTY FILTERS

OR INDOOR

COIL

INDOOR FAN

STOPPED OR

CYCLING ON

OVERLOAD

DAMAGED

REVERSING

VALVE

RESTRICTION IN

DISCHARGE LINE

OVERCHARGE

OR NON-

CONDENSABLES

IN SYSTEM

LOW

REFRIGERANT

CHARGE

LINE VOLTAGE

TOO HIGH OR

LOW

RUNS BUT

CYCLES ON

INTERNAL

OVERLOAD

DEFECTIVE FAN

MOTOR

CAPACITOR

LOOSE LEADS

FAN MOTOR

BURNED

OUT

LOW SUCTION

LOW HEAD

OUTDOOR FAN

STOPPED

LOOSE LEADS

AT OUTDOOR

FAN MOTOR

INTERNAL FAN

MOTOR KLIXON

OPEN

FAN MOTOR

BURNED OUT

DEFROST RELAY

N.C. CONTACTS

OPEN ON

CIRCUIT BOARD

COMPRESSOR

RUNS

INSUFFICIENT

HEATING

OUTDOOR FAN

RUNNING

REVERSING

VALVE STUCK

RESTRICTED

LIQUID LINE

PISTON

RESTRICTED OR

IS CLOGGED

UNDER-

CHARGED

OUTDOOR COIL

DIRTY

STRIP HEATERS

NOT OPERATING

OUTDOOR

THERMOSTAT

DEFECTIVE

ODT SETTING

TOO LOW

CAP TUBE

PINCHED OR

BULB NOT

SENSING TRUE

ODT

STRIP HEATER

RELAY OR

CONTACTOR

DEFECTIVE

OPENING IN

POWER CIRCUIT

TO HEATER

ELEMENTS

BROKEN FUSE

LINK

OPEN CONTROL

CIRCUIT

DEFECTIVE RUN

CAPACITOR

Fig. 54—Heat-Pump Troubleshooting Chart — Heating Cycle

DEFECTIVE RUN

CAPACITOR

(1-PH)

COMPRESSOR

BEARINGS

HIGH-LOAD

CONDITION

REVERSING VALVE JAMMED IN MIDPOSITION

HIGH

SUPERHEAT

FAN MOTOR

CONTACTS

WELDED CLOSED

IN DEFROST

RELAY

REVERSING

VALVE DID NOT

SHIFT

UNIT NOT

PROPERLY

CHARGED

STRAINER

RESTRICTED

OUTDOOR COIL

HEAVILY

FROSTED

DEFECTIVE

DEFROST

THERMOSTAT

DEFROST THERMOSTAT IN POOR PHYSICAL

CONTACT WITH

TUBE

DEFECTIVE

CIRCUIT BOARD

BAD ELECTRICAL

CONNECTION

ANYWHERE IN

DEFROST

CIRCUIT

BROKEN HEATER

ELEMENT

OPEN (KLIXON)

OVER

TEMPERATURE

THERMOSTAT

DEFECTIVE

ROOM

THERMOSTAT

(2ND STAGE)

A90206

—50—

—51—

—52—

Printed in U.S.A. sm01,025 Catalog No. 5356-109

Bryant R-22 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual