Friedrich 2007 User Manual

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Service Manual

2007

Room Air Conditioners

Temperature

Cooler

Warmer

Cool

Fan

Fan

Only

Speed

Timer

On/OffOperation

Start

Stop

Power

Money

Saver

Set Hr.

RAC-Svc-07(4-07)

TABLE OF CONTENTS

 

Introduction / Typical Unit Components.......................................................................................................................................

3

Warranty .......................................................................................................................................................................................

4

Routine Maintenance ...................................................................................................................................................................

5

Unit Identification / Nomenclature................................................................................................................................................

6

Performance Data.........................................................................................................................................................................

7

Electrical Data ..............................................................................................................................................................................

8

Functional Component Definitions ..............................................................................................................................................

9

Electronic Controls ..................................................................................................................................................................

9-10

Refrigeration Sequence of Operation.........................................................................................................................................

11

Sealed Refrigeration Repairs.................................................................................................................................................

11-12

Refrigerant Charging.............................................................................................................................................................

13-15

Troubleshooting .....................................................................................................................................................................

16-23

Wiring Diagrams....................................................................................................................................................................

24-35

The information contained in this manual is intended for use by a qualified service technician who is familiar with the safety procedures required in installation and repair, and who is equipped with the proper tools and test instruments.

Installation or repairs made by unqualified persons can result in hazards subjecting the unqualified person making such repairs to the risk of injury or electrical shock which can be serious or even fatal not only to them, but also to persons being served by the equipment.

If you install or perform service on equipment, you must assume responsibility for any bodily injury or property damage which may result to you or others. Friedrich Air Conditioning Company will not be responsible for any injury or property damage arising from improper installation, service, and/or service procedures.

2

INTRODUCTION

This service manual is designed to be used in conjunction with the installation manuals provided with each air conditioning system component.

This service manual was written to assist the professional RAC service technician to quickly and accurately diagnose and repair malfunctions.

This manual will deal with subjects in a general nature. (i.e. all text will not pertain to all models).

TYPICAL UNIT COMPONENTS

Fresh Air

Compressor

Capillary Tube

Liquid Filter Driers

Reversing Valve

Condenser Coil

(some models)

 

Front Cover

Discharge Air

System Switches

Outdoor Grille

 

Evaporator Coil

Sleeve

 

Return Air Grille/Filter

 

Blower Wheel

 

Blower Motor

Condenser Fan Blade

 

Basepan

IMPORTANT: It will be necessary for you to accurately identify the unit you are servicing, so you can be certain of a proper diagnosis and repair (See Unit Identification).

3

Friedrich Air Conditioning Company

P.O. Box 1540

San Antonio, TX 78295

210.357.4400

www.friedrich.com

ROOM AIR CONDITIONERS

LIMITED WARRANTY

FIRST YEAR

ANY PART: If any part supplied by FRIEDRICH fails because of a defect in workmanship or material within twelve months from date of original purchase, FRIEDRICH will repair the product at no charge, provided room air conditioner is reasonably accessible for service. Any additional labor cost for removing inaccessible units and/or charges for mileage related to travel by a Service Agency that exceeds 25 miles one way will be the responsibility of the owner. This remedy is expressly agreed to be the exclusive remedy within twelve months from the date of the original purchase.

SECOND THROUGH FIFTH YEAR

SEALED REFRIGERANT SYSTEM: If the Sealed Refrigeration System (defined for this purpose as the compressor, condenser coil, evaporator coil, reversing valve, check valve, capillary, filter drier, and all interconnecting tubing) supplied by FRIEDRICH in your Room Air Conditioner fails because of a defect in workmanship or material within sixty months from date of purchase, FRIEDRICH will pay a labor allowance and parts necessary to repair the Sealed Refrigeration System;PROVIDED FRIEDRICH will not pay the cost of diagnosis of the problem, removal, freight charges, and transportation of the air conditioner to and from the Service Agency, and the reinstallation charges associated with repair of the Sealed Refrigeration System. All such cost will be the sole responsibility of the owner. This remedy is expressly agreed to be the exclusive remedy within sixty months from the date of the original purchase.

APPLICABILITY AND LIMITATIONS: This warranty is applicable only to units retained within the Fifty States of the U.S.A., District of Columbia, and Canada. This warranty is not applicable to:

1.Air filters or fuses.

2.Products on which the model and serial numbers have been removed.

3.Products which have defects or damage which results from improper installation, wiring, electrical current characteristics, or maintenance; or caused by accident, misuse or abuse, fire, flood, alterations and/or misapplication of the product and/or units installed in a corrosive atmosphere, default or delay in performance caused by war, government restrictions or restraints, strikes, material shortages beyond the control of FRIEDRICH, or acts of God.

OBTAINING WARRANTY PERFORMANCE: Service will be provided by the FRIEDRICH Authorized Dealer or Service Organizationin your area. They are listed in the Yellow Pages. If assistance is required in obtaining warranty performance, write to: Room Air Conditioner Service Manager, Friedrich Air Conditioning Co., P.O. Box 1540, San Antonio, TX 78295-1540.

LIMITATIONS: THIS WARRANTY IS GIVEN IN LIEU OF ALL OTHER WARRANTIES. Anything in the warranty notwithstanding, ANY IMPLIED WARRANTIES OF FITNESS FOR PARTICULAR PURPOSE AND/OR MERCHANTABILITY SHALL BE LIMITED TO THE DURATION OF THIS EXPRESS WARRANTY. MANUFACTURER EXPRESSLY DISCLAIMS AND EXCLUDES ANY LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGE FOR BREACH OF ANY EXPRESSED OR IMPLIED WARRANTY.

NOTE: Some states do not allow limitations on how long an implied warranty lasts, or do not allow the limitation or exclusion of consequential or incidental damages, so the foregoing exclusions and limitations may not apply to you.

OTHER: This warranty gives you specific legal rights, and you may also have other rights which vary from state to state.

PROOF OF PURCHASE: Owner must provide proof of purchase in order to receive any warranty related services.

All service calls for explaining the operation of this product will be the sole responsibility of the consumer.

All warranty service must be provided by an Authorized FRIEDRICH Service Agency, unless authorized by FRIEDRICH prior to repairs being made.

(10-04)

4

ROUTINE MAINTENANCE

NOTE: Units are to be inspected and serviced by qualified service personnel only.

Routine maintenance is required annually or semi-annually,depending upon annual usage.

1.Clean the unit air intake filter at least every 250 to 300 fan hours of operation or when the unit’s indicator light is on if so equipped. Clean the filters with a mild detergent in warm water and allow to dry thoroughly before reinstalling.

2.The indoor coil (evaporator coil), the outdoor coil (condenser coil) and base pan should be inspected periodically (yearly or bi-yearly)and cleaned of all debris (lint, dirt, leaves, paper, etc.). Clean the coils and base pan with a soft brush and compressed air or vacuum. If using a pressure washer, be careful not to bend the aluminium fin pack. Use a sweeping up and down motion in the direction of the vertical aluminum fin pack when pressure cleaning coils. Cover all electrical components to protect them from water or spray. Allow the unit to dry thoroughly before reinstalling it in the sleeve.

NOTE: Do not use a caustic coil cleaning agent on coils or base pan. Use a biodegradable cleaning agent and degreaser.

Inspect the indoor blower housing, evaporator blade, condenser fan blade, and condenser shroud periodically (yearly or bi-yearly)and clean of all debris (lint, dirt, mold, fungus, etc.) Clean the blower housing area and blower wheel with an antibacterial / antifungal cleaner. Use a biodegradable cleaning agent and degreaser on condenser fan and condenser shroud. Use warm or cold water when rinsing these items. Allow all items to dry thoroughly before reinstalling them.

3.Periodically (at least yearly or bi-yearly):inspect all control components, both electrical and mechanical, as well as the power supply. Use proper testing instruments (voltmeter, ohmmeter, ammeter, wattmeter, etc.) to perform electrical tests. Use an air conditioning or refrigeration thermometer to check room, outdoor and coil operating temperatures. Use a sling psychrometer to measure wet bulb temperatures indoors and outdoors.

4.Inspect the surrounding area (inside and outside) to ensure that the units’ clearances have not been compromised or altered.

5.Inspect the sleeve and drain system periodically (at least yearly or bi-yearly)and clean of all obstructions and debris. Clean both areas with an antibacterial and antifungal cleaner. Rinse both items thoroughly with water and ensure that the drain outlets are operating correctly. Check the sealant around the sleeve and reseal areas as needed.

6.Clean the front cover when needed. Use a mild detergent. Wash and rinse with warm water. Allow it to dry thoroughly before reinstalling it in the chassis.

5

UNIT IDENTIFICATION

Model Number Code

S S 08 L 1 0 A

 

 

 

 

 

 

 

 

 

 

 

 

 

1st Digit – Function

 

 

 

 

 

 

 

 

 

 

 

8th Digit – Engineering

S = Straight Cool, Value Series

 

 

 

 

 

 

 

 

 

 

 

Major change

Y = Heat Pump

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

E = Electric Heat

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

K = Straight Cool

 

 

 

 

 

 

 

 

 

7th Digit – Options

 

 

 

 

 

 

 

 

 

R = Straight Cool

 

 

 

 

 

 

 

 

0

= Straight Cool &

X = Straight Cool

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Heat Pump Models

W = Thru-theWall,

 

 

 

 

 

 

 

 

1

= 1 KW Heat Strip, Normal

WallMaster Series

 

 

 

 

 

 

 

 

3

= 3 KW Heat Strip, Normal

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4

= 4 KW Heat Strip, Normal

 

 

 

 

 

 

 

 

 

5

= 5 KW Heat Strip, Normal

2nd Digit

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C = Casement

 

 

 

 

 

 

 

 

 

 

 

 

Q = Q-Star

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6th Digit – Voltage

S = Small Chassis

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M = Medium Chassis

 

 

 

 

 

 

 

 

1

= 115 Volts

 

 

 

 

 

 

 

 

L = Large Chassis

 

 

 

 

 

 

 

 

3

= 230-208Volts

H = HazardGard

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5th Digit

3rd and 4th Digit - Approximate

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Alphabetical Modifier

BTU/HR (Cooling)

 

 

 

 

 

 

 

 

 

 

 

 

Heating BTU/Hr capacity listed in the

 

 

 

 

 

 

 

 

 

 

 

 

Specification/Performance Data Section

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RAC Serial Number Identification Guide

Serial Number

 

L

C

G

R

00001

Decade Manufactured

 

 

 

 

 

L=0

C=3

F=6

J=9

 

 

 

Production Run Number

A=1

D=4

G=7

 

 

 

 

 

B=2

E=5

H=8

 

 

 

 

 

 

 

 

 

 

 

Year Manufactured

 

 

 

 

Product Line

A=1

D=4

G=7

K=0

 

 

 

R = RAC

B=2

E=5

H=8

 

 

 

 

P = PTAC

C=3

F=6

J=9

 

 

 

 

E = EAC

Month Manufactured

 

 

 

 

V = VPAK

A=Jan

D=Apr

G=Jul

K=Oct

 

 

 

H = Split

B=Feb

E=May

H=Aug

L=Nov

 

 

 

 

C=Mar

F=Jun

J=Sept

M=Dec

 

 

 

 

 

 

 

 

 

 

 

 

6

.humidity relative 40% & temp air outside F, degree 95 with humidity, relative 50% & .temp air room F, degrees 80 Conditions: *Rating

7

Q-Chassis

S-Chassis

M-Chassis

HazardGard L-Chassis

 

EVAP. AIR TEMP. DEG. F

CONDENSER

 

 

 

 

OPERATING

ELECTRICAL RATINGS

R-22

 

BREAKER

PERFORMANCE

Discharge

Suction

Super

Sub-

PRESSURES

REF.

 

FUSE

 

 

 

 

 

 

 

 

TEMPERATURE

 

 

 

 

 

 

Voltage

 

DATA* Cooling

Discharge

Temp.

DEG. F

Temp

Temp

Heat

Cooling

Suction

Discharge

Amps

Amps

Locked

Charge

 

60 Hertz

 

Air

Drop F.

 

 

 

 

 

Cool

Heat

Rotor Amps

in OZ.

 

Amps

 

 

 

 

 

 

 

 

 

XQ05L10A-B

56

24

119

151

58

13

20

89

255

4.9

 

28.0

21.4

115

15

XQ06L10A-A

55

26

121

157

65

13

27

87

261

5.0

 

24.0

21.0

115

15

XQ08L10A-A

52

29

128

167

60

13

33

81

283

6.8

 

36.2

22.1

115

15

XQ10L10A-A

50

31

130

176

65

20

29

75

287

9.2

 

44.0

19.2

115

15

XQ12L10A-A

51

29

126

166

51

6

30

75

271

11.0

 

56.0

31.0

115

15

EQ08L11A-A

52

29

124

173

69

21

29

82

283

6.5

10.7

36.2

20.0

115

15

YQ07L10A-A

55

25

126

177

73

26

23

79

275

6.8

5.6

36.2

19.5

115

15

YQ07L10A-B

55

25

126

177

73

26

23

79

275

6.8

5.6

36.2

19.5

115

15

SS08L10-C

56

24

119

154

73

22

24

85

252

6.6

 

36.2

23.0

115

15

SS08L10-D

56

24

116

157

68

16

18

86

250-260

6.6

 

36.2

27.0

115

15

SS10L10-C

57

23

117

166

65

16

23

82

243

7.5

 

42.0

26.0

115

15

KS12L10-C

52

29

122

169

61

13

24

82

266

9.0

 

44.0

26.5

115

15

SS12L10-D

53

27

124

169

62

13

30

82

266

9.3

 

44.0

32.0

115

15

KS15L10-B

51

30

125

182

62

16

29

77

278

12.2

 

61.0

29.0

115

15

SS14L10-C

53

27

125

184

62

15

27

78

268

12.3

 

61.0

29.2

115

15

SS12L30-C

57

24

121

170

67

17

27

83

258

5.4

 

21.0

28.0

208 / 230

15

SS12L30-D

58

22

122

174

66

17

28

84

261

4.7

 

21.0

31.0

208 / 230

15

SH15L30-B

54

26

206

129

61

16

98

76

258

8.2

 

 

28.5

208 / 230

15

SS16L30-C

50

31

130

176

53

8

35

77

279

7.9

 

35.0

32.1

208 / 230

15

ES12L33-B

56

25

121

167

65

15

28

83

256

4.8

15.1

21.0

28.0

208 / 230

20

ES12L33-C

58

22

122

174

66

17

28

84

261

4.7

15.1

21.0

31.0

208 / 230

20

ES16L33-B

49

32

130

179

50

8

34

75

279

7.4

15.1

35.0

32.0

208 / 230

20

YS09L10-D

60

20

116

164

71

18

17

89

239

7.1

8.5

44.0

25.1

115

15

YS13L33-B

58

23

123

175

69

22

29

79

266

5.2

5.3 / 15.1

24.0

30.0

208 / 230

20

YS13L33-C

51

29

122

172

65

18

30

80

269

5.5/5.1

5.7/5.3

24.0

32.0

1

20

KM24L30-B

50

31

132

187

56

14

37

70

287

11.2

 

68.0

53.0

208 / 230

20

YM18L34-B

49

31

125

182

64

22

27

72

271

8.5

8.7 / 18.6

41.0

43.0

208 / 230

30

YM18L34-C

61

19

126

187

67

24

28

73

280

9.2/8.75

8.8/8.3

41.0

43.0

208/230

30

EM18L34-B

49

31

125

175

63

21

31

72

271

8.1

18.9

42.0

39.5

208 / 230

15

KM18L30-B

49

31

125

175

63

21

31

72

271

8.1

 

42.0

39.5

208 / 230

15

SM18L30A-B

53

28

122

175

66

13

25

82

255

7.3

 

37.0

44.0

208 / 230

15

SM18L30A-C

54

26

121

171

61

13

25

81

262

7.7/7.1

 

37.0

45.0

208/230

15

SM21L30-C

50

31

127

185

57

15

34

73

274

9.4

 

43.0

45.0

208 / 230

15

SM21L30-D

48

32

125

173

52

13

25

75

278

9.6/9.3

 

43.0

43.0

208/230

15

EM24L35-B

50

31

132

187

56

14

37

70

287

11.2

25.0

68.0

53.0

208 / 230

30

SM24L30-B

50

31

132

187

56

14

37

70

287

11.2

 

68.0

53.0

208 / 230

20

SL28L30-C

53

28

128

172

56

13

29

73

259

13.0

 

68.0

50.1

208 / 230

20

SL36L30A-C

49

31

133

192

53

12

37

70

287

17.2

 

91.0

57.6

208 / 230

30

EL36L35A-C

49

32

133

194

53

13

38

70

302

18.0

25.0

91.0

60.0

208 / 230

30

YL24L35-C

52

29

122

175

65

23

29

72

262

10.9

11.2 / 24.6

68.0

74.0

208 / 230

30

YL24L35-D

52

28

124

175

65

22

29

74

268

11.9/11.1

11.7/11.0

68.0

73.0

208/230

30

SH15L30-B

54

26

206

129

61

16

98

76

258

8.2

 

 

28.5

208 / 230

15

SH20L30-B

46

34

125

196

52

8

28

75

271

10.1

 

 

39.0

208 / 230

20

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

DATA PERFORMANCE

ELECTRICAL DATA

Wire Size

Use ONLY wiring size recommended for

 

single outlet branch circuit.

Fuse/Circuit

Use ONLY type and size fuse or HACR

Breaker

circuit breaker indicated on unit’s rating

 

plate. Proper current protection to the unit

 

is the responsibility of the owner.

Grounding

Unit MUST be grounded from branch

 

circuit through service cord to unit, or

 

through separate ground wire provided on

 

permanently connected units. Be sure that

 

branch circuit or general purpose outlet is

 

grounded.

Receptacle

The field supplied outlet must match plug on

 

service cord and be within reach of service

 

cord. Do NOT alter the service cord or plug.

 

Do NOT use an extension cord. Refer to

 

the table above for proper receptacle and

 

fuse type.

ELECTRIC SHOCK HAZARD.

Turn off electric power before service or installation.

All electrical connections and wiring MUST be installed by a qualified electrician and conform to the National Electrical Code and all local codes which have jurisdiction.

Failure to do so can result in property damage, personal injury and/or death.

The consumer - through the AHAM Room Air Conditioner Certification Program - can be certain that the AHAM Certification Seal accurately states the unit’s cooling and heating capacity rating, the amperes and the energy efficiency ratio.

8

FUNCTIONAL COMPONENT DEFINITIONS

MECHANICAL COMPONENTS

Bellows condensate valve Temperature-sensitivevalve that opens up to drain off condensate water when the outside temperature falls below 40°F and closes when the outside temperature reaches 58°F.

Vent door Allows introduction of fresh air into the room and/or exhausts stale room air outside (on select models.)

Plenum assembly Diffuser with directional louvers used to direct the conditioned airflow.

Blower wheel Attaches to the indoor side of the fan motor shaft and is used for distributing unconditioned, room side air though the heat exchanger and delivering conditioned air into the room.

ELECTRICAL COMPONENTS cont’d

MoneySaver® switch When engaged, it sends the power supply to the fan motor through the thermostat, which allows for acycle-fanoperation.

Fan Motor Dual-shaftedfan motor operates the indoor blower wheel and the condenser fan blade simultaneously.

Solenoid Used to energize the reversing valve on all heat pump units.

Heating element Electric resistance heater, available in 3.3, 4.0 or 5.2 kW on select TwinTemp® models.

Heat anticipator Used to provide better thermostat and room air temperature control.

Slinger fan blade Attaches to the outdoor side of the fan motor shaft and is used to move outside air through the condenser coil, while slinging condensate water out of the base pan and onto the condenser coil, thus lowering the temperature and pressures within the coil.

ELECTRICAL COMPONENTS

Thermostat Used to maintain the specified room side comfort level

System switch Used to regulate the operation of the fan motor, the compressor or to turn the unit off. For troubleshooting, refer to the wiring diagrams and schematics in the back of this service manual.

Capacitor Reduces line current and steadies the voltage supply, while greatly improving the torque characteristics of the fan motor and compressor motor.

HERMETIC COMPONENTS

Compressor Motorized device used to compress refrigerant through the sealed system.

Reversing valve Afour-wayswitching device used on all heat pump models to change the flow of refrigerant to permit heating or cooling.

Check valve Apressure-operateddevice used to direct the flow of refrigerant to the proper capillary tube, during either the heating or cooling cycle.

Capillary tube A cylindrical meter device used to evenly distribute the flow of refrigerant to the heat exchangers (coils.)

ELECTRONIC CONTROLS

TESTING THE ELECTRONIC CONTROLS

CHECK FILTER light will come on after 250 hours of use. Touch CHECK FILTER to reset.

Set

Check

Hour

Filter

 

Press to reset

 

 

Money

Fan

Mode

 

Saver®

Only

 

 

 

Temp

 

 

OF/OC

 

 

 

 

1-4

Smart

 

Fan

Speed

Fan

 

 

 

 

 

A/C

A/C

Timer

Timer

Stop

Start

On/ Off

 

 

 

Electronic Control

9

ELECTRONIC CONTROLS

TESTING THE ELECTRONIC CONTROL XQ/WS BOARDS & QME BOARDS

Activating Test Mode: Activate test mode by pressing at the same time the“MODE” button and the temperature“DOWN” buttonon XQ & WS models. LEDs for Hour, Start, and Stop will blink 1 bps while Test Mode is active.

Activate test mode by pressing at the same time the “MONEY SAVER” button and the“CHECK FILTER” button onQME models. LED for the Filter Alert will blink 1 bps while Test Mode is active.

Test Mode has duration of 90 minutes. Test Mode can be activated under any conditions, including Off. Test Mode is cancelled by pressing the On/Off button, unplugging the unit, or when the 90 minutes is timed out. All settings revert to the factory default settings of Cool, 75° F, Timer and Set Hour features are nonfunctional.

Test Mode overrides the three-minutelockout, all delays for compressor and fan motor start / speed change, and no delay when switching modes.

Test Mode default settings are ON, Money Saver, 60° F, and High fan speed.

Activating Error Code Mode: (Submode of Test Mode) Unit must be in Test Mode to enter Error Code Mode

Activate Error Code Mode by pressing the “TIMER ON/OFF” button on XQ & WS models. LED for the“TIMER ON/OFF” will flash 1 bps while Error Code Mode is active. Pressing the“TEMP/HR + “ button will display 00. Consecutive presses will scroll through all error codes logged. Press the“TEMP/ HR - “ button to see the reverse order of all error codes logged. When the end of logged error codes is reached the temperature set point will appear.

Activate Error Code Mode by pressing at the same time the “A/CSTART”buttonandthe“ON/OFF”buttononQMEmodels. LED for the“TIMERON/OFF”will flash 1 bps while Error Code Mode is active. Pressing the“WARMER”button will display 00. Consecutive presses will scroll through all error codes logged. Pressthe“COOLER”buttontoseethereverseorderofallerror codes logged. When the end of logged error codes is reached the temperature set point will appear.

TESTING THE ELECTRONIC CONTROL

ERROR CODE LISTINGS

IMPORTANT: Error Codes are cleared from the log by exiting from Error Code Mode. To exit on XQ models, press Timer On/Off button. To exit QME models, press A/C Start and On/Off buttons. Or unplug unit to exit Error Code Mode. Plug unit in after 5 seconds to resume normal operation of unit.

TESTING THE ELECTRONIC CONTROL

ERROR CODE LISTINGS

E1 SHORT CYCLE SITUATION: Keyboard is fine. Investigate and define short cycling problem.

E2 KEYBOARD STUCK ERROR: If key button(s) are pressed continuously for twenty seconds or more. If MODE key is stuck, unit will default to cool. Exit Error Code Mode to see if error “E2” is no longer displayed and unit is functioning. Replace board if “E2” still displays after exiting Error Code Mode.

E3 FROST PROBE OPEN: If ohm value is present, replace board.

E4 FROST PROBE SHORT: Replace board.

E5 INDOOR PROBE OPEN: Replace board.

E6 INDOOR PROBE SHORT: Replace board.

NOTE: All Error Code displays for Frost & Indoor Probe will allow unit to operate. Unit may or will ice up if faulty components not replaced.

FROST PROBE SENSOR: disables compressor at 35° F.

INDOOR PROBE SENSOR: Control range is 60° F to 90° F +/- 2° F.

Indoor temperature will be displayed by pressing: (QME units) The Fan Speedbutton and the Warmerbutton.

(XQ units) The Fan Speedbutton and the Temp Upbutton.

The indoor temperature will be displayed for 10 seconds. The display will change back to the Set Point temperature by pressing any key button except for the On/Off button. The indoor temperature can be viewed in all modes, including test mode.

Check Filter: TheCheck Filter indicator turns on after the fan motor has been operating for 250 hours. TheCheck Filter indicator is reset by pressing theCheck Filter button one time only,. Power failures will not reset the 250 hour timer. All time elapsed is stored in memory and resumes counting after power is restored.

Keep Alive: The electronic control has a memory to retain all functions and status as set up by the user in the event of a power failure. Once power is restored to the unit there is a two second delay before the fan comes on and approximately three minutes delay before the compressor is activated, providing that the mode was set for cooling and the set point temperature has not been met in the room.

10

REFRIGERATION SYSTEM SEQUENCE OF OPERATION

A good understanding of the basic operation of the refrigeration system is essential for the service technician. Without this understanding, accurate troubleshooting of refrigeration system problems will be more difficult and time consuming, if not (in some cases) entirely impossible. The refrigeration system uses four basic principles (laws) in its operation they are as follows:

1.“Heat always flows from a warmer body to a cooler body.”

2.“Heat must be added to or removed from a substance before a change in state can occur”

3.“Flow is always from a higher pressure area to a lower pressure area.”

4.“The temperature at which a liquid or gas changes state is dependent upon the pressure.”

The refrigeration cycle begins at the compressor. Starting the compressor creates a low pressure in the suction line which draws refrigerant gas (vapor) into the compressor. The compressor then “compresses” this refrigerant, raising its pressure and its (heat intensity) Temperature.

The refrigerant leaves the compressor through the discharge line as a hot high pressure gas (vapor). The refrigerant enters the condenser coil where it gives up some of its heat. The condenser fan moving air across the coil’s finned surface facilitates the transfer of heat from the refrigerant to the relatively cooler outdoor air.

When a sufficient quantity of heat has been removed from the refrigerant gas (vapor), the refrigerant will “condense” (i.e. change to a liquid). Once the refrigerant has been condensed (changed) to a liquid it is cooled even further by the air that continues to flow across the condenser coil.

The RAC design determines at exactly what point (in the condenser) the change of state (i.e. gas to a liquid) takes place. In all cases, however, the refrigerant must be totally condensed (changed) to a liquid before leaving the condenser coil.

The refrigerant leaves the condenser coil through the liquid line as a warm high pressure liquid. It next will pass through the refrigerant drier (if so equipped). It is the function of the drier to trap any moisture present in the system, contaminants, and large particulate matter.

The liquid refrigerant next enters the metering device. The metering device is a capillary tube. The purpose of the metering device is to “meter” (i.e. control or measure) the quantity of refrigerant entering the evaporator coil.

In the case of the capillary tube this is accomplished (by design) through size (and length) of device, and the pressure difference present across the device.

Since the evaporator coil is under a lower pressure (due to the suction created by the compressor) than the liquid line,

the liquid refrigerant leaves the metering device entering the evaporator coil. As it enters the evaporator coil, the larger area and lower pressure allows the refrigerant to expand and lower its temperature (heat intensity). This expansion is often referred to as “boiling”. Since the unit’s blower is moving Indoor air across the finned surface of the evaporator coil, the expanding refrigerant absorbs some of that heat. This results in a lowering of the indoor air temperature, hence the “cooling” effect.

The expansion and absorbing of heat cause the liquid refrigerant to evaporate (i.e. change to a gas). Once the refrigerant has been evaporated (changed to a gas), it is heated even further by the air that continues to flow across the evaporator coil.

The particular system design determines at exactly what point (in the evaporator) the change of state (i.e. liquid to a gas) takes place. In all cases, however, the refrigerant must be totally evaporated (changed) to a gas before leaving the evaporator coil.

The low pressure (suction) created by the compressor causes the refrigerant to leave the evaporator through the suction line as a cool low pressure vapor. The refrigerant then returns to the compressor, where the cycle is repeated.

Refrigerant System Components

Suction

Discharge

Line

Line

Evaporator

Condenser

Coil

Coil

 

Compressor

Metering

Refrigerant Drier

Device

Liquid

Refrigerant

Line

Dryer

 

SEALED REFRIGERATION SYSTEM REPAIRS

IMPORTANT

ANY SEALED SYSTEM REPAIRS TO COOL-ONLYMODELS REQUIRE THE INSTALLATION OF A LIQUID LINE DRIER. ALSO, ANY SEALED SYSTEM REPAIRS TO HEAT PUMP MODELS REQUIRE THE INSTALLATION OF A SUCTION LINE DRIER.

11

EQUIPMENT REQUIRED

1.Voltmeter

2.Ammeter

3.Ohmmeter

4.E.P.A. Approved Refrigerant Recovery System.

5.Vacuum Pump (capable of 200 microns or less vacuum.)

6.Acetylene Welder

7.Electronic Halogen Leak Detector (G.E. Type H-6or equivalent.)

8.Accurate refrigerant charge measuring device such as:

a.Balance Scales - 1/2 oz. accuracy

b.Charging Board - 1/2 oz. accuracy

9.High Pressure Gauge - (0 - 400 lbs.)

10.Low Pressure Gauge - (30 - 150 lbs.)

11.Vacuum Gauge - (0 - 1000 microns)

EQUIPMENT MUST BE CAPABLE OF:

1.Recovery CFC’s as low as 5%.

2.Evacuation from both the high side and low side of the system simultaneously.

3.Introducing refrigerant charge into high side of the system.

4.Accurately weighing the refrigerant charge actually introduced into the system.

5.Facilities for flowing nitrogen through refrigeration tubing during all brazing processes.

HERMETIC COMPONENT REPLACEMENT

The following procedure applies when replacing components in the sealed refrigeration circuit or repairing refrigerant leaks. (Compressor, condenser, evaporator, capillary tube, refrigerant leaks, etc.)

1.Recover the refrigerant from the system at the process tube located on the high side of the system by installing a line tap on the process tube. Apply gauge from process tube to EPA approved gauges from process tube to EPA approved recovery system. Recover CFC’s in system to at least 5%.

2.Cut the process tube below pinch off on the suction side of the compressor.

3.Connect the line from the nitrogen tank to the suction process tube.

4.Drift dry nitrogen through the system and un-solderthe more distant connection first. (Filter drier, high side process tube, etc.)

5.Replace inoperative component, and always install a new filter drier. Drift dry nitrogen through the system when making these connections.

HERMETIC COMPONENT REPLACEMENT cont’d

6.Pressurize system to 30 PSIG with proper refrigerant and boost refrigerant pressure to 150 PSIG with dry nitrogen.

7.Leak test complete system with electric halogen leak detector, correcting any leaks found.

8.Reduce the system to zero gauge pressure.

9.Connect vacuum pump to high side and low side of system with deep vacuum hoses, or copper tubing. (Do not use regular hoses.)

10.Evacuate system to maximum absolute holding pressure of 200 microns or less. NOTE: This process can be accelerated by use of heat lamps, or by breaking the vacuum with refrigerant or dry nitrogen at 5,000 microns. Pressure system to 5 PSIG and leave in system a minimum of 10 minutes. Release refrigerant, and proceed with evacuation of a pressure of 200 microns or less.

11.Break vacuum by charging system from the high side with the correct amount of liquid refrigerant specified.

This will prevent boiling the oil out of the crankcase, and damage to the compressor due to over heating.

NOTE: If the entire charge will not enter the high side, allow the remainder to enter the low side in small increments while operating the unit.

12.Restart unit several times after allowing pressures to stabilize. Pinch off process tubes, cut and solder the ends. Remove pinch off tool, and leak check the process tube ends.

SPECIALPROCEDUREINTHECASEOFCOMPRESSOR MOTOR BURNOUT

1.Recover all refrigerant and oil from the system.

2.Remove compressor, capillary tube and filter drier from the system.

3.Flush evaporator condenser and all connecting tubing with dry nitrogen or equivalent, to remove all contamination from system. Inspect suction and discharge line for carbon deposits. Remove and clean if necessary.

4.Reassemble the system, including new drier strainer and capillary tube.

5.Proceed with processing as outlined under hermetic component replacement.

ROTARYCOMPRESSORSPECIALTROUBLESHOOTING AND SERVICE

Basically, troubleshooting and servicing rotary compressors is the same as on the reciprocating compressor with only one main exception:

NEVER, under any circumstances, charge a rotary compressor through the LOW side. Doing so would cause permanent damage to the new compressor.

12

REFRIGERANT CHARGING

NOTE: BECAUSE THE RAC SYSTEM IS A SEALED SYSTEM, SERVICE PROCESS TUBES WILL HAVE TO BE INSTALLED. FIRST INSTALL A LINE TAP AND REMOVE REFRIGERANT FROM SYSTEM. MAKE NECESSARY SEALED SYSTEM REPAIRS AND VACUUM SYSTEM. CRIMP PROCESS TUBE LINE AND SOLDER END SHUT. DO NOT LEAVE A SERVICE VALVE IN THE SEALED SYSTEM.

Proper refrigerant charge is essential to proper unit operation. Operating a unit with an improper refrigerant charge will result in reduced performance (capacity) and/or efficiency. Accordingly, the use of proper charging methods during servicing will insure that the unit is functioning as designed and that its compressor will not be damaged.

Too much refrigerant (overcharge) in the system is just as bad (if not worse) than not enough refrigerant (undercharge). They both can be the source of certain compressor failures if they remain uncorrected for any period of time. Quite often, other problems (such as low air flow across evaporator, etc.) are misdiagnosed as refrigerant charge problems. The refrigerant circuit diagnosis chart will assist you in properly diagnosing these systems.

An overcharged unit will at times return liquid refrigerant (slugging) back to the suction side of the compressor eventually causing a mechanical failure within the compressor. This mechanical failure can manifest itself as valve failure, bearing failure, and/or other mechanical failure. The specific type of failure will be influenced by the amount of liquid being returned, and the length of time the slugging continues.

Not enough refrigerant (Undercharge) on the other hand, will cause the temperature of the suction gas to increase to the point where it does not provide sufficient cooling for the

compressor motor. When this occurs, the motor winding temperature will increase causing the motor to overheat and possibly cycle open the compressor overload protector. Continued overheating of the motor windings and/or cycling of the overload will eventually lead to compressor motor or overload failure.

METHOD OF CHARGING

The acceptable method for charging the RAC system is the Weighed in Charge Method. The weighed in charge method is applicable to all units. It is the preferred method to use, as it is the most accurate.

The weighed in method should always be used whenever a charge is removed from a unit such as for a leak repair, compressor replacement, or when there is no refrigerant charge left in the unit. To charge by this method, requires the following steps:

1.Install a piercing valve to remove refrigerant from the sealed system. (Piercing valve must be removed from the system before recharging.)

2.Recover Refrigerant in accordance with EPA regulations.

3.Install a process tube to sealed system.

4.Make necessary repairs to system.

5.Evacuate system to 250 - 300 microns or less.

6.Weigh in refrigerant with the property quantity of R-22refrigerant.

7.Start unit, and verify performance.

8.Crimp the process tube and solder the end shut.

NOTE: In order to access the sealed system it will be necessary to install Schrader type fittings to the process tubes on the discharge and suction of the compressor. Proper refrigerant recovery procedures need to be adhered to as outlined in EPA Regulations. THIS SHOULD ONLY BE ATTEMPTED BY QUALIFIED SERVICE PERSONNEL.

13

REFRIGERANT CHARGING cont’d

UNDERCHARGED REFRIGERANT SYSTEMS

An undercharged system will result in poor performance (low pressures, etc.) in both the heating and cooling cycle.

Whenever you service a unit with an undercharge of refrigerant, always suspect a leak. The leak must be repaired before charging the unit.

To check for an undercharged system, turn the unit on, allow the compressor to run long enough to establish working pressures in the system (15 to 20 minutes).

During the cooling cycle you can listen carefully at the exit of the metering device into the evaporator; an intermittent hissing and gurgling sound indicates a low refrigerant charge.

Intermittent frosting and thawing of the evaporator is another indication of a low charge, however, frosting and thawing can also be caused by insufficient air over the evaporator.

Checks for an undercharged system can be made at the compressor . If the compressor seems quieter than normal, it is an indication of a low refrigerant charge. A check of the amperage drawn by the compressor motor should show a lower reading. (Check the Unit Specification.) After the unit has run 10 to 15 minutes, check the gauge pressures.

Gauges connected to system with an undercharge will have low head pressures and substantially low suction pressures.

NOTE: Heat pump refrigeration drawing

OVERCHARGED REFRIGERANT SYSTEMS

Compressor amps will be near normal or higher. Noncondensables can also cause these symptoms. To confirm, remove some of the charge, if conditions improve, system may be overcharged. If conditions don’t improve, Noncondensables are indicated.

Whenever an overcharged system is indicated, always make sure that the problem is not caused by air flow problems. Improper air flow over the evaporator coil may indicate some of the same symptoms as an overcharged system.

An over charge can cause the compressor to fail, since it would be “slugged” with liquid refrigerant.

The charge for any system is critical. When the compressor is noisy, suspect an overcharge, when you are sure that the air quantity over the evaporator coil is correct. Icing of the evaporator will not be encountered because the refrigerant will boil later if at all. Gauges connected to system will usually have higher head pressure (depending upon amount of overcharge). Suction pressure should be slightly higher.

14

REFRIGERANT CHARGING cont’d

RESTRICTED REFRIGERANT SYSTEM

A quick check for either condition begins at the evaporator. With a partial restriction, there may be gurgling sounds at the metering device entrance to the evaporator. The evaporator in a partial restriction could be partially frosted or have an ice ball close to the entrance of the metering device. Frost may continue on the suction line back to the compressor.

Often a partial restriction of any type can be found by feel, as there is a temperature difference from one side of the restriction to the other.

With a complete restriction, there will be no sound at the metering device entrance. An amperage check of the compressor with a partial restriction may show normal current when compared to the unit specification. With a complete restriction the current drawn may be considerably less than normal, as the compressor is running in a deep vacuum (no load). Much of the area of the condenser will be relatively cool since most or all of the liquid refrigerant will be stored there.

The following conditions are based primarily on a system in the cooling mode.

Troubleshooting a restricted refrigerant system can be difficult. The following procedures are the more common problems and solutions to these problems. There are two types of refrigerant restrictions: Partial restrictions and complete restrictions.

A partial restriction allows some of the refrigerant to circulate through the system.

With a complete restriction there is no circulation of refrigerant in the system.

Restricted refrigerant systems display the same symptoms as a “low-chargecondition.”

When the unit is shut off, the gauges may equalize very slowly.

Gauges connected to a completely restricted system will run in a deep vacuum. When the unit is shut off, the gauges will not equalize at all.

15

TROUBLESHOOTING TOUCH TEST CHART: TO SERVICE REVERSING VALVES

NORMAL FUNCTION OF VALVE

VALVE

DISCHARGETUBE fromCompressor

SUCTIONTUBEto Compressor

Tube toINSIDE COIL

TubeOUTSIDEto COIL

LEFT Pilot CapillaryTube

RIGHT Pilot

CapillaryTube

NOTES:

 

OPERATING

* TEMPERATURE OF VALVE BODY

CONDITION

** WARMER THAN VALVE BODY

 

 

 

 

1

2

3

 

4

5

6

POSSIBLE CAUSES

CORRECTIONS

Normal Cooling

Hot

Cool

Cool

Hot

*TVB

TVB

 

 

as (2)

as (1)

 

 

 

 

 

 

 

 

 

Normal Heating

Hot

Cool

Hot

Cool

*TVB

TVB

 

 

as (1)

as (2)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MALFUNCTION OF VALVE

 

 

Check Electrical circuit and coil

 

 

 

No voltage to coil.

Repair electrical circuit.

 

 

 

 

Defective coil.

Replace coil.

 

 

 

 

 

 

 

 

 

Check refrigeration charge

 

 

 

Low charge.

Repair leak, recharge system.

 

 

 

 

Pressure differential too high.

Recheck system.

 

 

 

 

 

 

 

 

Valve will not

Hot

Cool

Cool,

 

Hot,

*TVB

Hot

 

De-energizesolenoid, raise head pres-

 

 

as (2)

 

as (1)

 

 

 

sure, reenergize solenoid to break dirt

shift from cool

 

 

 

 

 

 

 

Pilot valve okay. Dirt in one bleeder hole.

loose. If unsuccessful, remove valve, wash

to heat.

 

 

 

 

 

 

 

 

out. Check on air before installing. If no

 

 

 

 

 

 

 

 

 

movement, replace valve, add strainer to

 

 

 

 

 

 

 

 

 

discharge tube, mount valve horizontally.

 

 

 

 

 

 

 

 

 

Stop unit. After pressures equalize, restart

 

 

 

 

 

 

 

 

Piston cup leak

with solenoid energized. If valve shifts,

 

 

 

 

 

 

 

 

reattempt with compressor running. If still

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

no shift, replace valve.

 

Hot

Cool

Cool,

 

Hot,

*TVB

*TVB

Clogged pilot tubes.

Raise head pressure, operate solenoid to

 

as (2)

 

as (1)

free. If still no shift, replace valve.

Valve will not

 

 

 

 

 

 

 

 

Cool,

 

Hot,

 

 

Both ports of pilot open. (Back seat port did

Raise head pressure, operate solenoid to

shift from cool

Hot

Cool

 

Hot

Hot

free partially clogged port. If still no shift,

as (2)

 

as (1)

not close).

to heat.

 

 

 

 

 

 

 

 

replace valve.

 

Warm

Cool

Cool,

 

Hot,

*TVB

Warm

Defective Compressor.

Replace compressor

 

as (2)

 

as (1)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Not enough pressure differential at start of

Check unit for correct operating pressures

 

Hot

Warm

Warm

 

Hot

*TVB

Hot

stroke or not enough flow to maintain pres-

and charge. Raise head pressure. If no

 

 

 

 

 

 

 

 

sure differential.

shift, use valve with smaller port.

 

 

 

 

 

 

 

 

 

 

Starts to shift

 

 

 

 

 

 

 

Body damage.

Replace valve

Hot

Warm

Warm

 

Hot

Hot

Hot

Both ports of pilot open.

Raise head pressure, operate solenoid.

but does not

 

If no shift, use valve with smaller ports.

 

 

 

 

 

 

 

 

complete

Hot

Hot

Hot

 

Hot

*TVB

Hot

Body damage.

Replace valve

reversal.

 

 

 

 

 

 

 

Valve hung up at mid-stroke.Pumping vol-

Raise head pressure, operate solenoid.

 

 

 

 

 

 

 

 

ume of compressor not sufficient to maintain

If no shift, use valve with smaller ports.

 

 

 

 

 

 

 

 

reversal.

 

 

 

 

 

 

 

 

 

 

Hot

Hot

Hot

 

Hot

Hot

Hot

Both ports of pilot open.

Raise head pressure, operate solenoid.

 

 

If no shift, replace valve.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Apparent

Hot

Cool

Hot,

 

Cool,

*TVB

*TVB

Piston needle on end of slide leaking.

Operate valve several times, then recheck.

as (1)

 

as (2)

If excessive leak, replace valve.

 

 

 

 

 

 

leap in heating.

Hot

Cool

Hot,

 

Cool,

** WVB

** WVB

Pilot needle and piston needle leaking.

Operate valve several times, then recheck.

 

as (1)

 

as (2)

If excessive leak, replace valve.

 

 

 

 

 

 

 

 

Hot

Cool

Hot,

 

Cool,

*TVB

*TVB

Pressure differential too high.

Stop unit. Will reverse during equalization

 

as (1)

 

as (2)

period. Recheck system

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Clogged pilot tube.

Raise head pressure, operate solenoid to

 

 

 

 

 

 

 

 

free dirt. If still no shift, replace valve.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Raise head pressure, operate solenoid.

 

 

 

Hot,

 

Cool,

 

 

 

Remove valve and wash out. Check on

 

Hot

Cool

 

Hot

*TVB

Dirt in bleeder hole.

air before reinstalling, if no movement,

Will not shift

as (1)

 

as (2)

 

 

 

 

 

 

replace valve. Add strainer to discharge

 

 

 

 

 

 

 

 

from heat to

 

 

 

 

 

 

 

 

tube. Mount valve horizontally.

 

 

 

 

 

 

 

 

Stop unit. After pressures equalize, restart

cool.

 

 

 

 

 

 

 

 

 

 

Hot,

 

Cool,

 

 

 

with solenoid de-energized.If valve shifts,

 

Hot

Cool

 

Hot

*TVB

Piston cup leak.

reattempt with compressor running. If it

 

as (1)

 

as (2)

 

 

 

 

 

 

 

still will not reverse while running, replace

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

the valve.

 

Hot

Cool

Hot,

 

Cool,

Hot

Hot

Defective pilot.

Replace valve.

 

as (1)

 

as (2)

 

 

 

 

 

 

 

 

 

Warm

Cool

Warm,

 

Cool,

Warm

*TVB

Defective compressor.

Replace compressor

 

as (1)

 

as (2)

 

 

 

 

 

 

 

 

16

COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS

Problem

Possible Cause

Action

 

Low voltage

Check voltage at compressor. 115V & 230V units

 

will operate at 10% voltage variance

 

 

 

 

 

 

T-statnot set cold enough or inoperative

Set t-statto coldest position. Testt-stat& replace

 

if inoperative

 

 

 

 

 

 

Compressor hums but cuts off on B10 overload

Hard start compressor. Direct test compressor. If

 

compressor starts, add starting components

Compressor

 

 

 

does not run

Open or shorted compressor windings

Check for continuity & resistance

 

 

 

 

Open overload

Test overload protector & replace if inoperative

 

Open capacitor

Test capacitor & replace if inoperative

 

Inoperative system switch

Test for continuity in all positions. Replace if

 

inoperative

 

 

 

Broken, loose or incorrect wiring

Refer to appropriate wiring diagrams to check

 

wiring

 

 

 

 

 

Problem

Possible Cause

Action

 

Inoperative system switch

Test switch & replace if inoperative

 

Broken, loose or incorrect wiring

Refer to applicable wiring diagram

Fan motor

Open capacitor

Test capacitor & replace if inoperative

does not run

Fan speed switch open

Test switch & replace if inoperative

 

 

Inoperative fan motor

Test fan motor & replace if inoperative (be sure

 

internal overload has had time to reset)

 

 

Problem

Possible Cause

Action

 

Undersized unit

Refer to industry standard sizing chart

 

T-statopen or inoperative

Set to coldest position. Test t-stat& replace if

 

necessary

 

 

 

Dirty filter

Clean as recommended in Owner's Manual

 

Dirty or restricted condenser or evaporator coil

Use pressure wash or biodegradable cleaning

Does not cool or

agent to clean

 

only cools slightly

Poor air circulation

Adjust discharge louvers. Use high fan speed

 

Fresh air or exhaust air door open on applicable

Close doors. Instruct customer on use of this

 

models

feature

 

Low capacity - undercharge

Check for leak & make repair

 

Compressor not pumping properly

Check amperage draw against nameplate. If not

 

conclusive, make pressure test

 

 

17

COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS

Problem

Possible Cause

Action

 

 

Replace fuse, reset breaker. If repeats, check

 

Fuse blown or circuit tripped

fuse or breaker size. Check for shorts in unit

 

 

wiring & components

Unit does not run

Power cord not plugged in

Plug it in

System switch in "OFF" position

Set switch correctly

 

 

Inoperative system switch

Test for continuity in each switch position

 

Loose or disconnected wiring at switch or other

Check wiring & connections. Reconnect per

 

components

wiring diagram

Problem

Possible Cause

Action

 

Dirty filter

Clean as recommended in Owner's Manual

 

Restricted airflow

Check for dirty or obstructed coil. Use pressure

 

wash or biodegradable cleaning agent to clean

 

 

Evaporator coil

Inoperative t-stat

Test for shorted t-stator stuck contacts

Short of refrigerant

De-icecoil & check for leak

freezes up

 

Inoperative fan motor

Test fan motor & replace if inoperative

 

 

De-icecoil. Check temp. differential (delta T)

 

Partially restricted capillary tube

across coil. Touch test coil return bends for same

 

 

temp. Test for low running current

Problem

Possible Cause

Action

 

Excessive heat load

Unit undersized. Test cooling performance &

 

replace with larger unit if needed

 

 

 

Restriction in line

Check for partially iced coil & check temperature

 

split across coil

Compressor runs

 

 

Check for oil at silver soldered connections.

continually & does

 

Refrigerant leak

Check for partially iced coil. Check split across

not cycle off

 

coil. Check for low running amperage

 

 

 

T-statcontacts stuck

Check operation of t-stat.Replace if contacts

 

remain closed.

 

 

 

T-statincorrectly wired

Refer to appropriate wiring diagram

Problem

Possible Cause

Action

 

T-statcontacts stuck

Disconnect power to unit. Remove cover of t-stat

 

& check if contacts are stuck. If so, replace t-stat

 

 

 

 

 

T-statdoes not turn

T-statset at coldest point

Turn to higher temp. setting to see if unit cycles

unit off

off

 

 

Incorrect wiring

Refer to appropriate wiring diagrams

 

Unit undersized for area to be cooled

Refer to industry standard sizing chart

 

 

 

18

COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS

Problem

Possible Cause

Action

 

Overload inoperative. Opens too soon

Check operation of unit. Replace overload if

 

system operation is satisfactory

 

 

 

Compressor restarted before system pressures

Allow a minimum of 2 minutes to allow pressures

 

to equalize before attempting to restart. Instruct

 

equalized

 

customer of waiting period

 

 

 

 

Check voltage with unit operating. Check for

Compressor runs for

Low or fluctuating voltage

other appliances on circuit. Air conditioner should

be in separate circuit for proper voltage & fused

short periods only.

 

separately

Cycles on overload

 

 

Incorrect wiring

Refer to appropriate wiring diagram

 

 

Shorted or incorrect capacitor

Check by substituting a known good capacitor of

 

correct rating

 

 

 

Restricted or low air flow through condenser coil

Check for proper fan speed or blocked

 

condenser

 

 

 

Compressor running abnormally hot

Check for kinked discharge line or restricted

 

condenser. Check amperage

 

 

Problem

Possible Cause

Action

 

Loss of charge in t-statbulb

Place jumper across t-statterminals to check if

T-statdoes not

unit operates. If unit operates, replace t-stat.

 

turn unit on

Loose or broken parts in t-stat

Check as above

 

Incorrect wiring

Refer to appropriate wiring diagram

Problem

Possible Cause

Action

 

Poorly installed

Refer to Installation Manual for proper installation

 

 

 

 

Fan blade striking chassis

Reposition - adjust motor mount

Noisy operation

 

Check that compressor grommets have not

Compressor vibrating

deteriorated. Check that compressor mounting

 

 

 

parts are not missing

 

Improperly mounted or loose cabinet parts

Check assembly & parts for looseness, rubbing

 

& rattling

 

 

Problem

Possible Cause

Action

 

Evaporator drain pan overflowing

Clean obstructed drain trough

 

Condensation forming on base pan

Evaporator drain pan broken or cracked. Reseal

 

or replace

 

 

 

Poor installation resulting in rain entering the

Check installation instructions. Reseal as

Water leaks into the

room

required

room

Condensation on discharge grille louvers

Clean the dirty evaporator coil. Use pressure

 

wash or biodegradable cleaning agent to clean

 

 

 

Chassis gasket not installed

Install gasket, per Installation manual

 

Downward slope of unit is too steep

Refer to installation manual for proper installation

 

 

 

19

COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS

Problem

 

Possible Cause

Action

 

Sublimation:

When

Ensure that foam gaskets are installed in

 

between window panes & in between the unit &

 

unconditioned saturated, outside air mixes with

 

the sleeve. Also, ensure that fresh air/exhaust

 

conditioned air, condensation forms on the cooler

 

vents (on applicable models) are in the closed

 

surfaces

 

Water "spitting"

 

position & are in tact

 

 

 

 

 

into room

 

 

Follow installation instructions to ensure that

 

Downward pitch of installation is too steep

downward pitch of installed unit is no less than

 

 

 

1/4" & no more than 3/8"

 

Restricted coil or dirty filter

Clean & advise customer of periodic cleaning &

 

maintenance needs of entire unit

 

 

 

Problem

Possible Cause

Action

 

Insufficient air circulation thru area to be air

Adjust louvers for best possible air circulation

 

conditioned

 

 

Excessive moisture

Oversized unit

Operate in "MoneySaver" position

 

Inadequate vapor barrier in building structure,

Advise customer

 

particularly floors

 

 

Problem

Possible Cause

Action

 

T-statdifferential too narrow

Replace t-stat

T-statshort cycles

Plenum gasket not sealing, allowing discharge air

Check gasket. Reposition or replace as needed

to short cycle t-stat

 

 

Restricted coil or dirty filter

Clean & advise customer of periodic cleaning &

 

maintenance needs of entire unit

 

 

Problem

Possible Cause

Action

 

Anticipator (resistor) wire disconnected at t-stat

Refer to appropriate wiring diagram

 

or system switch

 

 

 

 

 

Prolonged off

 

Disconnect plus from outlet. Remove resistor

 

from bracket. Insert plug & depress "COOL"

cycles (automatic

 

Anticipator (resistor) shorted or open

& "FAN AUTOMATIC" buttons. Place t-statto

operation)

 

warmest setting. Feel resistor for temperature. If

 

 

 

 

no heat, replace resistor

 

 

 

 

Partial loss of charge in t-statbulb causing a wide

Replace t-stat

 

differential

 

Problem

Possible Cause

Action

 

Evaporator drain pan cracked or obstructed

Repair, clean or replace as required

 

 

 

 

Water in compressor area

Detach shroud from pan & coil. Clean & remove

 

old sealer. Reseal, reinstall & check

Outside water leaks

 

Obstructed condenser coil

Use pressure wash or biodegradable cleaning

 

 

agent to clean

 

 

 

Fan blade/slinger ring improperly positioned

Adjust fan blade to 1/2" of condenser coil

 

 

 

20

HEAT / COOL ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS

Problem

Possible Cause

Action

 

Heat anticipator (resistor) shorted (on applicable

Disconnect power to unit. Remove resistor from

 

t-statbulb block. Plus in unit & allow to operate.

 

models)

 

Feel resistor for heat. If not heat, replace resistor

Room temperature

 

 

 

uneven

Wide differential - partial loss of t-statbulb charge

Replace t-stat& check

(Heating cycle)

 

 

 

 

 

 

 

Refer to appropriate wiring diagram. Resistor is

 

Incorrect wiring

energized during "ON" cycle of compressor or

 

 

fan.

Problem

Possible Cause

Action

 

Incorrect wiring

Refer to appropriate wiring diagram

 

Defrost control timer motor not advancing

Check for voltage at "TM" & "TM1" on timer. If no

 

(applicable models)

voltage, replace control

 

Defrost control out of calibration (applicable

If outside coil temperature is 25F or below, &

 

preselected time limit has elapsed, replace

 

models)

Unit will not defrost

defrost control

 

 

 

If contacts remain closed between terminals "2"

 

Defrost control contacts stuck

& "3" of the defrost control after preselected time

 

 

interval has passed, replace control

 

Defrost control bulb removed from or not making

Reinstall & be assured that good bulb to coil

 

good coil contact

contact is made

Problem

Possible Cause

Action

 

Exhaust or fresh air door open

Check if operating properly. Instruct customer on

 

proper use of control

 

 

 

Dirty filter

Clean as recommended in Owner's Manual

 

 

Check heat rise across coil. If unit operates

 

Unit undersized

efficiently, check if insulation can be added

 

to attic or walls. If insulation is adequate,

 

 

Does not heat

 

recommend additional unit or larger one

 

 

adequately

 

T-statshould close at 38°F. Check continuity of

 

Outdoor t-statopen (applicable models)

control. If temperature is below 38°F, replace

 

 

control

 

Heater hi-limitcontrol cycling on & off

Check for adequate fan air across heater. Check

 

control for open at 160°F & close at 150°F

 

 

 

Shorted supplementary heater

Ohmmeter check, approx. 32-35ohms

 

Incorrect wiring

Check applicable wiring diagram

21

HEAT / COOL ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS

Problem

Possible Cause

Action

 

Incorrect wiring

Refer to applicable wiring diagram

 

Defective solenoid coil

Check for continuity of coil

Unit cools when

 

Block condenser coil & switch unit to cooling.

 

Allow pressure to build up in system, then

heat is called for

Reversing valve fails to shift

switch to heating. If valve fails to shift, replace

 

 

 

 

valve.

 

Inoperative system switch

Check for continuity of system switch

Problem

Possible Cause

Action

 

Heating capillary tube partially restricted

Check for partially starved outer coil. Replace

 

heating capillary tube

 

 

 

 

Switch unit several times from heating to

Cooling adequate,

Check valve leaking internally

cooling. Check temperature rise across

coil. Refer to specification sheet for correct

but heating

 

 

temperature rise

insufficient

 

 

De-energizesolenoid coil, raise head

 

 

 

Reversing valve failing to shift completely;

pressure, energize solenoid to break loose.

 

bypassing hot gas

If valve fails to make complete shift, replace

 

 

valve.

TROUBLESHOOTING CHART — COOLING

REFRIGERANT SYSTEM DIAGNOSIS – HEATING

Low Suction Pressure

High Suction Pressure

Low Head Pressure

High Head Pressure

Low Load Conditions

High Load Conditions

Low Load Conditions

High Load Conditions

Low Air Flow Across

High Air Flow Across

Refrigerant System

Low Air Flow Across

Indoor Coil

Indoor Coil

Restriction

Outdoor Coil

Refrigerant System

Reversing Valve not

Reversing Valve not

Overcharged

Restriction

Fully Seated

Fully Seated

 

Undercharged

Overcharged

Undercharged

Noncondensables (air)

in System

 

 

 

Moisture in System

Defective Compressor

Defective Compressor

 

22

TROUBLESHOOTING CHART — HEATING

REFRIGERANT SYSTEM DIAGNOSIS – HEATING

Low Suction Pressure

High Suction Pressure

Low Head Pressure

High Head Pressure

Low Airflow

Outdoor Ambient Too High

Refrigerant System

Outdoor Ambient Too High

Across Outdoor Coil

for Operation in Heating

Restriction

For Operation In Heating

Refrigerant System

Reversing Valve not

Reversing Valve not

Low Airflow Across

Restriction

Fully Seated

Fully Seated

Indoor Coil

Undercharged

Overcharged

Undercharged

Overcharged

Moisture in System

Defective Compressor

Defective Compressor

Noncondensables (air)

ELECTRICAL TROUBLESHOOTING CHART — HEAT PUMP

HEAT PUMP

SYSTEM COOLS WHEN

HEATING IS DESIRED.

Is Line Voltage

 

Is the Selector Switch

Present at the Solenoid

NO

Set for Heat?

 

 

YES

 

 

Is the Solenoid Coil Good?

NO

Replace the Solenoid Coil

 

 

YES

 

 

Reversing Valve Stuck

 

 

Replace the Reversing Valve

23

MODELS

XQ05L10-A,B;XQ06L10-A,B,C,D;XQ08L10-A,B;XQ10L10-A,B;XQ12L10-A,B

24

MODELS

KS10L10-A,RS10L10-A,KS12L10-A,KS12L30-A,KS15L10-A,RS15L10-A,RS16L30-A,

RM18L30-A,KM18L30-A,KM21L30-A,RM24L30-A,KM24L30-A

25

MODELS

SS08L10-A/B,SS10L10-A/B,SS12L10-A/B;SS12L30-A/B,SS14L10-A/B,

SS16L30-A/B,SM18L30-A/B,SM21L30-A/B,SM24L30-A/B

26

MODEL

SL36L30-A

27

MODEL

SL28L30-A

28

MODELS

SL36L30-B

29

MODEL

EQ08L11-A

30

MODELS

ES12L33-A,ES16L33-A,EM18L34-A,EM24L35-A

31

MODEL

EL36L35-A

32

MODEL

YS09L10-A,YS09L10-B

33

MODELS

YS13L33-A,YM18L34-A

34

MODELS

YL24L35-A

35

Friedrich Air Conditioning Co.

Post Office Box 1540 • San Antonio, Texas 78295-1540

4200 N. Pan Am Expressway • San Antonio, Texas 78218-5212(210)357-4400• FAX (210)357-4480

www.friedrich.com

Printed in the U.S.A.

RAC-Svc-07(4-07)