Friedrich RAC-SVC-06 User Manual

Service Manual

2006

Room Air Conditioners

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TABLE OF CONTENTS

INTRODUCTION

Warranty ............................................................................. 3

Routine Maintenance ......................................................... 4

Unit Identiﬁ cation / Nomenclature ...................................... 5

Performance Data .............................................................. 6

Electrical Data .................................................................... 7

Functional Component Deﬁ nitions .................................... 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

Thi s ser vic e manu al is des igned to be u sed in conjun ction 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

Capillary Tube

Reversing Valve (some models)

Front Cover

System Switches

Evaporator Coil

Return Air Grille/Filter

Blower Wheel

Blower Motor

Fresh Air

Compressor

Basepan

Liquid Filter Driers

Condenser Coil

Discharge Air

Outdoor Grille

Sleeve

Condenser Fan Blade

The information contained in this manual is intended for use by a qualiﬁ ed ser vice techn ician who i s famili ar with t he safet y procedures requ ired in install ation an d repair, and who is equipped with the proper tools and test instruments.

Installation or repairs made by unqualiﬁ ed 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.

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 Identiﬁ cation).

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

OBTAINING WARRANTY PERFORMANCE: Service will be provided by the FRIEDRICH Authorized Dealer or Service Organization in 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.

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.

(10-04)

ROUTINE MAINTENANCE

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

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

1. Clean the unit air intake ﬁ lter at least every 250 to 300 fan hours of operation or when the unit’s indicator light is on if so equipped. Clean the ﬁ lters 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 ﬁ n pack. Use a sweeping up and down motion in the direction of the vertical aluminum ﬁ n 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.

UNIT IDENTIFICATION

Model Number Code

S S 08 L 1 0 A

1st Digit – Function

S = Straight Cool, Value Series Y = Heat Pump E = Electric Heat K = Straight Cool R = Straight Cool X = Straight Cool W = Thru-the Wall,

WallMaster Series

2nd Digit

C = Casement Q = Q-Star S = Small Chassis M = Medium Chassis L = Large Chassis H = HazardGard

3rd and 4th Digit - Approximate BTU/HR (Cooling)

Heating BTU/Hr capacity listed in the Speciﬁ cation/Performance Data Section

8th Digit – Engineering

Major change

7th Digit – Options

0 = Straight Cool & Heat Pump Models

1 = 1 KW Heat Strip, Normal 3 = 3 KW Heat Strip, Normal 4 = 4 KW Heat Strip, Normal 5 = 5 KW Heat Strip, Normal

6th Digit – Voltage

1 = 115 Volts 3 = 230-208 Volts

5th Digit

Alphabetical Modiﬁ er

RAC Serial Number Identiﬁ cation Guide

Serial Number Decade Manufactured

L=0 C=3 F=6 J=9

A=1 D=4 G=7

B=2 E=5 H=8

Year Manufactured

A=1 D=4 G=7 K=0

B=2 E=5 H=8

C=3 F=6 J=9

Month Manufactured

A=Jan D=Apr G=Jul K=Oct

B=Feb E=May H=Aug L=Nov

C=Mar F=Jun J=Sept M=Dec

L C G R 00001

Production Run Number

Product Line

R = RAC

P = PTAC

E = EAC

V = VPAK

H = Split

PERFORMANCE DATA

Model

EVAPORATOR AIR TEMP °F

Discharge

Air

CONDENSER

TEMP °F

Temp

Drop °F Suction Discharge

DISCHARGE

TEMP

SUCTION

TEMP

SUPER

HEAT

SUB-

COOLING

OPERATING PRESSURES

ELECTRICAL RATINGS

Amps

Cool

Amps

Heat

Locked

Rotor Amps

R-22

REF.

Charge

in OZ.

BREAKER

FUSE

Voltage

60 Hertz

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

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 ﬁ eld 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 qualiﬁ ed 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 A HAM Room Air Conditioner Cer tiﬁ cation Program - can be certain that the AHAM Certiﬁ cation Seal accurately states the unit ’s cooling and heating capacity rating, the amperes and the energy efﬁ ciency ratio.

FUNCTIONAL COMPONENT DEFINITIONS

MECHANICAL COMPONENTS

Bellows condensate valve Temperature-sensitive valve

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 airﬂ ow.

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 a cycle-fan operation.

Fan Motor Dual-shafted fan 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 A four-way switching device used on all heat pump models to change the ﬂ ow of refrigerant to permit heating or cooling.

Check valve A pressure-operated device used to direct the ﬂ ow of refrigerant to the proper capillary tube, during either the heating or cooling cycle.

Capillary tube A cylindr ic al met er dev ice used t o eve nly di stribute the ﬂ ow 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.

Cool

Cooler

Speed

1-4

A/C

Stop

On/Off

Set Hour

Clock

Money

Saver

Warmer

Smart

Fan

A/C

Start

Check

Filter

Press to reset

Fan

Only

0F/0

Timer

On/Off

Electronic Control

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” button on 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 on QME 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-minute lockout, 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 b y pressi ng the “TIMER ON/OFF” button on XQ & WS models. LED for the “TIMER ON/OFF” will ﬂ ash 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 ﬂ ash 1 bps while Error Code Mode is active. Pressing the “WARMER” button will display 00. Consecutive presses will scroll through all error codes logged. Press the “COOLER” 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.

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 un plug u nit t o ex i t Error Code Mode. P l ug unit in a f ter 5 seconds to resume normal operation of unit.

TESTING THE ELECTRONIC CONTROL

ERROR CODE LISTINGS

E1 SHORT CYCLE SITUATION: Keyboard is fine.

Investigate and deﬁ ne 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 f unc tioning. 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 Speed button and the Warmer button.

(XQ units) The Fan Speed button and the Temp Up button.

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: The Check Filter indicator turns on after the fan motor has been operating for 250 hours. The Check Filter indicator is reset by pressing the Check 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.

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 difﬁ cult and time consuming, if not (in some cases) entirely impossible. The refrigeration system uses four basic pr inciples (laws) in its operation they are as follows:

1. “Heat always ﬂ ows 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 ﬁ nned surface facilitates the transfer of heat from the refrigerant to the relatively cooler outdoor air.

When a sufﬁ cient 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 ﬂ ow 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

li ne as a w arm high pressure liqui d. It n ext will pass thr ough 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 ﬁ nned 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 ﬂ ow 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 Line

Evaporator Coil

Metering Device

Refrigerant Dryer

Refrigerant Drier

SEALED REFRIGERATION SYSTEM REPAIRS

Discharge Line

Condenser Coil

Compressor

Liquid

Line

IMPORTANT

ANY SEALED SYSTEM REPAIRS TO COOL-ONLY MODELS REQUIRE THE INSTALLATION OF A LI QU ID LINE DRIER. ALSO, A NY SE ALED SYSTEM REPAIRS TO HEAT PUMP MODELS REQUIRE THE INSTALLATION OF A SUCTION LINE DRIER.

EQUIPMENT REQUIRED

HERMETIC COMPONENT REPLACEMENT cont’d

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-6 or

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 ﬂ owing 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

le aks. (Comp resso r, condenser, evaporator, capillar y tube, refrigerant leaks, etc.)

1. Recover the refrigerant from the system at the process

tub e located on t he high si de of the s ystem by ins talling 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-solder

the more distant connection ﬁ rst. (Filter drier, high side process tube, etc.)

5. Replace inoperative component, and always install a

new ﬁ lter drier. Drift dry nitrogen through the system when making these connections.

6. P res sur ize sy stem to 30 PS IG w ith proper refr igerant 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 speciﬁ ed.

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.

SPECIAL PROCEDURE IN THE CASE OF COMPRESSOR MOTOR BURNOUT

1. Recover all refrigerant and oil from the system.

2. Remove compressor, capillary tube and ﬁ lter 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.

ROTARY COMPRESSOR SPECIA L TROUBLESHOOTI NG 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.

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