Bryant R-22 User Manual

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—

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