Friedrich RAC-SVC-06 User Manual

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Service Manual

2006

Room Air Conditioners

RAC-Svc-06(3-06)

TABLE OF CONTENTS

 

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

3

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

4

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

5

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

6

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

7

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

8

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

8-9

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

10

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

10-11

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

12-14

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

15-22

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

23-35

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.

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).

2

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)

3

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.

4

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 Modifi er

BTU/HR (Cooling)

 

 

 

 

 

 

 

 

 

 

 

 

Heating BTU/Hr capacity listed in the

 

 

 

 

 

 

 

 

 

 

 

 

Specifi cation/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

 

 

 

 

 

 

 

 

 

 

 

 

5

PERFORMANCE DATA

 

EVAPORATOR

CONDENSER

DISCHARGE

SUCTION

SUPER

SUB-

OPERATING

ELECTRICAL RATINGS

R-22

 

BREAKER

 

AIR TEMP °F

TEMP °F

TEMP

TEMP

HEAT

COOLING

PRESSURES

REF.

 

FUSE

 

 

 

 

Voltage

Model

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Locked

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Discharge

Temp

 

 

 

 

 

 

 

Amps

Amps

Rotor

Charge

 

60 Hertz

 

Air

Drop °F

 

 

 

 

 

Suction

Discharge

Cool

Heat

Amps

in OZ.

 

Amps

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Q-Chassis

XQ05L10-A

54

27

120

150

68

17

19

85

256

4.8

28.0

18.3

115

15

XQ06L10-A

55

26

121

157

65

13

27

87

261

5.0

24.0

21.0

115

15

XQ08L10-A

52

29

128

167

60

13

33

81

283

6.8

36.2

22.1

115

15

XQ10L10-A

50

31

130

176

65

20

29

75

287

9.2

44.0

19.2

115

15

XQ12L10-A

51

29

126

166

51

6

30

75

271

11.0

56.0

31.0

115

15

EQ08L11-A

52

29

124

173

69

21

29

82

283

6.5

10.7

36.2

20.0

115

15

S-Chassis

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SS08L10-B

56

24

119

154

68

13

26

85

252

6.6

36.2

23.0

115

15

KS10L10-A

52

29

117

162

64

15

21

83

244

8.0

42.0

26.0

115

15

RS10L10-A

58

23

117

166

68

15

21

83

244

8.0

42.0

26.0

115

15

SS10L10-B

57

23

117

166

65

16

23

82

243

7.5

42.0

26.0

115

15

KS12L10-A

52

29

122

169

61

13

24

82

266

9.0

44.0

26.5

115

15

RS12L10-A

53

27

124

169

62

13

30

82

266

9.3

44.0

32.0

115

15

SS12L10-B

53

27

124

169

62

13

30

82

266

9.3

44.0

32.0

115

15

KS15L10-A

51

30

125

182

62

16

29

77

278

12.2

61.0

29.0

115

15

RS15L10-A

53

27

125

184

62

16

27

77

278

12.3

61.0

29.0

115

15

SS14L10-B

53

27

125

184

62

15

27

78

268

12.3

61.0

29.2

115

15

KS12L30-A

48

32

129

176

48

34

36

76

287

12.3

24.0

31.0

208 / 230

15

SS12L30-B

57

24

121

170

67

17

27

83

258

5.4

21.0

28.0

208 / 230

15

SS16L30-B

50

31

130

176

53

8

35

77

279

7.9

35.0

32.1

208 / 230

15

RS16L30-A

50

31

130

176

53

8

35

77

279

7.4

35.0

32.0

208 / 230

15

ES12L33-A

56

25

121

167

65

15

28

83

256

4.8

15.1

21.0

28.0

208 / 230

20

ES16L33-A

49

32

130

179

50

8

34

75

279

7.4

15.1

35.0

32.0

208 / 230

20

YS09L10-A

60

20

116

164

71

18

17

89

239

7.1

8.5

44.0

25.1

115

15

YS09L10-B

60

20

116

164

71

18

17

89

239

7.1

8.5

44.0

25.1

115

15

YS09L10A-A

60

20

116

164

71

18

17

89

239

7.1

8.5

44.0

25.1

115

15

YS13L33-A

58

23

123

175

69

22

29

79

266

5.2

5.3 / 15.1

24.0

30.0

208 / 230

20

M-Chassis

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

KM24L30-A

50

31

132

187

56

14

37

70

287

11.2

68.0

53.0

208 / 230

20

RM24L30-A

50

31

132

187

56

14

37

70

287

11.2

68.0

53.0

208 / 230

20

YM18L34-A

49

31

125

182

64

22

27

72

271

8.5

8.7 / 18.6

41.0

43.0

208 / 230

30

RM18L30-A

49

31

125

175

63

21

31

72

271

8.7

42.0

39.5

208 / 230

15

EM18L34-A

49

31

125

175

63

21

31

72

271

8.1

18.9

42.0

39.5

208 / 230

15

KM18L30-A

49

31

125

175

63

21

31

72

271

8.1

42.0

39.5

208 / 230

15

SM18L30-A

53

28

122

175

66

13

25

82

255

7.3

37.0

44.0

208 / 230

15

KM21L30-A

50

31

127

185

57

15

34

73

274

9.4

43.0

45.0

208 / 230

15

SM21L30-A

50

31

127

185

57

15

34

73

274

9.4

43.0

45.0

208 / 230

15

EM24L35

50

31

132

187

56

14

37

70

287

11.2

25.0

68.0

53.0

208 / 230

30

SM24L30

50

31

132

187

56

14

37

70

287

11.2

 

68.0

53.0

208 / 230

20

L-Chassis

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SL28L30-A

53

28

128

172

56

13

29

73

259

13.0

68.0

50.1

208 / 230

20

SL36L30-A

49

31

133

192

53

12

37

70

287

17.2

91.0

57.6

208 / 230

30

SL36L30-B

49

31

133

192

53

12

37

70

287

17.2

91.0

57.6

208 / 230

30

EL36L35-A

49

32

133

194

53

13

38

70

302

18.0

25.0

91.0

60.0

208 / 230

30

YL24L35-A

52

29

122

175

65

23

29

72

262

10.9

11.2 / 24.6

68.0

74.0

208 / 230

30

Casement

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SC06L10-A

47

33

128

166

47

14

23

74

290

6.7

 

40.0

20.0

115

15

HazardGard

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SH15L30-A

54

26

206

129

61

16

98

76

258

8.2

 

 

28.5

208 / 230

15

SH20L30-A

46

34

125

196

52

8

28

75

271

10.1

 

 

39.0

208 / 230

20

6

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.

7

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.

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 specifi ed 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.

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.

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.

PM

72

Set Hour

Check

 

Clock

Filter

 

 

Press to reset

On/Off

 

Cool

Money

Fan

Saver

Only

 

Cooler

Warmer

0F/0C

Speed

Smart

 

1-4

Fan

 

A/C

A/C

Timer

Stop

Start

On/Off

Electronic Control

8

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/C START” button and the“ON/OFF” button on QME models. LED for the“TIMER ON/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 codeslogged.Pressthe“COOLER”buttontoseethereverse order of all error 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.

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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.

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