Friedrich KS12J30A User Manual

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Figure 7: System Control Panel

Figure 8: System Control Switch

to supply a small amount of heat to the bulb area to prevent long “off cycles” in the “Cool-FanAuto” (MoneySaver) position (see Figure 10.) A current feedback through the fan motor windings during “off cycle” completes the circuit to the resistor.

RANGE:

Cooling Model Thermostat

 

(Part No. 618-225-00)

60°F (± 2°) to 92°F (± 4°),

TEST:

Remove wires from thermostat. Turn the thermostat to its coldest position. Check to see if there is continuity between the two terminals. Turn the thermostat to its warmest position. Check continuity to see if thermostat contacts open. NOTE: Temperature must be within range listed to check thermostat. Refer to the troubleshooting section in this manual for additional information on thermostat testing.

Figure 9: Thermostat

THERMOSTAT (Figure 9)

A cross ambient thermostat is used on all standard chassis units. In addition to cycling the unit in a heating or cooling operation, the thermostat will terminate the cooling cycle in the event ice forms on the evaporator coil, in this case the thermostat functions as a de-icecontrol. A resistor (anticipator) is positioned within a plastic block

THERMOSTAT ADJUSTMENT

No attempt should be made to adjust thermostat. Due to the sensitivity of the internal mechanism and the sophisticated equipment required to check the calibration, it is suggested that the thermostat be replaced rather than calibrated.

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RESISTOR

(Heat Anticipator)

Failure of the resistor will cause prolonged“off” and “on” cycles of the unit. When replacing a resistor, be sure and use the exact replacement. Resistor ratings are as follows:

115 Volt - 5,000 ohms 3 watt

230 Volt - 20,000 ohms 3 watt

Figure 10 RESISTOR

MONEYSAVER® SWITCH

(Rocker Switch) - (See Figure 11)

This rocker switch can be depressed to either YES orNO. In theYES position you will get the most economical operation. Both the fan and compressor will cycle on and off together, maintaining the selected temperature at a more constant level and reducing the humidity more efficiently.This control will only operate when the unit is in a cooling mode. In theNO position, the fan will run constantly as long as the unit is in the cooling mode.

TEST:

Disconnect leads from switch. Depress switch to function being tested.

1.When YES is depressed, there should be continuity between terminals “1” and “2”.

2.When NO is depressed, there should be continuity between terminals “2” and “3”.

FIGURE 11 ROCKER SWITCH

SEALED REFRIGERATION SYSTEM REPAIRS

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:

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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.Recovering CFCs 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.)

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 speeded up 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. Recover refrigerant, and proceed with evacuation of a pressure of 200 microns or a minimum of 10 %.

11.Break vacuum by charging system from the high side with the correct amount of refrigerant specified.This will prevent boiling the oil out of the crankcase.

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.

1.Recover the refrigerant from the system at the pro-

cess tube located on the high side of the system by SPECIAL PROCEDURE IN THE CASE OF

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 CFCs 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 unsolder the 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.

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

MOTOR COMPRESSOR 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.

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ROTARY COMPRESSOR SPECIAL

TROUBLESHOOTING AND SERVICE

Basically, troubleshooting and servicing rotary compressors is the same as on the reciprocating compressor with only a few exceptions.

1.Because of the spinning motion of the rotary, the mounts are critical. If vibration is present, check the mounts carefully.

2.The electrical terminals on the rotary are in a different order than the reciprocating compressors. The terminal markings are on the cover gasket. Use your wiring diagram to insure correct connections.

REFRIGERANT CHARGE

1.The refrigerant charge is extremely critical. Measure charge carefully - as exact as possible to the nameplate charge.

2.The correct method for charging the rotary is to introduce liquid refrigerant into the high side of the system with the unit off. Then start compressor and enter the balance of the charge, gas only, into the low side.

The introduction of liquid into the low side, without the use of a capillary tube, will cause damage to the discharge valve of the rotary compressor.

NOTE: All inoperative compressors returned to Friedrich must have all lines properly plugged with the plugs from the replacement compressor.

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Troubleshooting Cooling

PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

 

 

 

Low voltage.

Check for voltage at compressor. 1115 volt and 230 volt

 

 

units will operate at 10% voltage variance.

 

Thermostat not set cold

Set thermostat to coldest position. Test thermostat and

 

enough or inoperative.

replace if inoperative.

Compressor does not

Compressor hums but cuts off

Hard start compressor. Direct test compressor. If com-

on overload.

pressor starts, add starting components.

run.

Open or shorted compressor

Check for continuity and resistance.

 

 

windings.

 

 

Open overload.

Test overload protector and replace if inoperative.

 

 

 

 

Open capacitor.

Test capacitor and replace if inoperative.

 

Inoperative system switch.

Test for continuity in all positions. Replace if inoperative.

 

Broken, loose or incorrect

Refer to appropriate wiring diagram to check wiring.

 

wiring.

 

 

 

 

PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

Inoperative system switch.

Test switch and replace if inoperative.

 

Broken, loose or incorrect

Refer to applicable wiring diagram.

Fan motor does not

wiring.

 

run.

Open capacitor.

Test capacitor and replace if inoperative.

 

Fan speed switch open.

Test switch and replace if inoperative.

 

Inoperative fan motor.

Test fan motor and replace if inoperative (be sure internal

 

 

overload has had time to reset).

PROBLEM

POSSIBLE CAUSE

 

TO CORRECT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Undersized unit.

 

Refer to Sizing Charts.

 

 

Thermostat open or inopera-

 

Set to coldest position. Test thermostat and replace if

 

 

tive.

 

necessary.

 

 

Dirty filter

 

Clean as recommended in the Owner's Manual.

 

 

Dirty or plugged condenser or

 

Use steam or detergents to clean.

 

Does not cool, or

evaporator coil.

 

 

 

cools only slightly.

Pool air circulation in area

 

Adjust discharge air louvers. Use high fan speed.

 

 

being cooled.

 

 

 

 

Fresh air or exhaust air door

 

Close doors. Instruct customer on use of this feature.

 

 

open on applicable models.

 

 

 

 

 

 

 

 

 

Low capacity - undercharge.

 

Clean for leak and make repair.

 

 

Compressor not pumping

 

Check amperage draw against nameplate. If not conclu-

 

 

properly.

 

sive, make pressure test.

 

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PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

 

 

 

 

 

 

Fuse blown or circuit tripped.

Replace fuse, reset breaker. If repeats, check fuse or

 

 

 

breaker size. Check for shorts in unit wiring and compo-

Unit does not run.

 

 

nents

 

Power cord not plugged in.

Plug in power cord

 

 

 

 

System switch in "Off" position.

Set switch correctly.

 

 

Inoperative system switch.

Test for continuity in each switch position.

 

 

Loose or disconnected wiring at

Check wiring and connections. Reconnect per wiring

 

 

switch or other components

diagram.

 

 

 

 

PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

 

 

 

 

 

 

Dirty filter.

Clean as recommended in Owener's Manual.

 

 

Restricted air flow.

Check for dirty or obstructed coil - clean as required.

Evaporator coil

 

Inoperative thermostat.

Test for shorted thermostat or stuck contacts.

freezes up.

Short of refrigerant.

De-icecoil and check for leak.

 

 

Inoperative fan motor.

Test fan motor and replace if inoperative.

 

 

Partially restricted capillary.

De-icecoil. Check temperature differential across coil.

 

 

 

Touch test coil return bends for same temperature. Test for

 

 

 

low running current.

PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

 

 

Excessive heat load.

Unit undersized. Test cooling performance of unit. Re-

 

 

 

place with larger unit.

Compressor runs

Restriction in line.

Check for partially iced coil. Check temperature split

 

across coil.

continually. Does not

 

 

 

Refrigerant leak.

Check for oil at silver soldered connections. Check for

cycle off.

 

partially iced coil. Check split across coil. Check for low

 

 

 

 

 

 

running amperage.

 

 

Thermostat contacts stuck.

Check operation of thermostat. Replace if contacts remain

 

 

 

closed.

 

 

Thermostat incorrectly wired.

Refer to appropriate wiring diagram.

PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

Thermostat does not

 

Thermostat contacts stuck.

Replace thermostat.

 

Thermostat set at coldest point.

Turn to higher temperature setting to see if unit

turn unit off.

 

 

 

cycles off.

 

 

 

 

 

Incorrect wiring.

Refer to appropriate wiring diagram.

 

 

Unit undersized for area to be

Refer to Sizing Chart.

 

 

cooled.

 

 

 

 

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PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

 

 

 

Overload inoperative. Opens

Check operation of unit. Replace overload if system

Compressor attempts

too soon.

operation is satisfactory.

Compressor attempts to start

Allow a minimum of two (2) minutes for pressures to

to start, or runs for

before system pressures are

equalize before attempting to restart. Instruct customer

short periods only.

equalized.

of waiting period.

Cycles on overload.

 

 

Low or fluctuating voltage.

Check voltage with unit operating. Check for other

 

 

appliances on the circuit. The air conditioner should be

 

 

on a separate circuit for proper voltage, and be fused

 

 

separately.

 

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

Check for proper fan speed or blocked condenser.

 

condenser coil.

 

 

 

 

 

Compressor running abnormally

Check for kinked discharge line or restricted condenser.

 

hot.

Check amperage.

PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

 

 

 

Loss of charge in thermostat

Place jumper across thermostat terminals to check if unit

 

bulb.

operates. If unit operates, replace the thermostat.

Thermostat does not

Loose or broken parts in thermo-

Check as above.

stat.

 

turn unit on.

 

Incorrect wiring.

Refer to appropriate wiring diagram.

 

PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

 

 

 

Poorly installed unit.

Refer to Installation Instructions for proper installation.

Noisy operation.

Fan blade striking chassis.

Reposition - adjust motor mount.

Compressor vibrating.

Check that compressor grommets have not deteriorated.

 

 

Improperly mounted or loose

Check that compressor mounting parts are not missing.

 

cabinet parts.

 

PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

 

 

 

Evaporator drain pan overflow-

Clean obstructed drain trough.

 

ing.

 

Water leaks into

Condensation forming on base

Evaporator drain pan broken or cracked. Reseal or replace.

room.

pan.

 

 

Poor installation resulting in rain

Check installation instructions. Reseal as required.

 

entering room.

 

 

Condensation on discharge

Dirty evaporator coil - clean. Very high humidity level.

 

grilles.

 

Page 17

PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

 

 

 

 

 

 

Thermostat differential too

Replace thermostat.

 

 

narrow.

 

Thermostat short

Plenum gasket not sealing,

Check gasket, reposition or replace.

allowing discharge air to short

 

cycles.

cycle the thermostat.

 

 

 

Restricted coil or dirty filter.

Clean and advise customer of periodic cleaning of filter.

 

 

Thermostat bulb touching

Adjust bulb bracket.

 

 

thermostat bulb support bracket.

(Applicable models.)

PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

Anticipator (resistor) wire

Refer to appropriate wiring diagram.

 

disconnected at thermostat or

 

Prolonged off cycles

system switch.

 

(automatic operation).

Anticipator (resistor shorted or

Replace thermostat block and resistor.

 

open).

 

 

(Applicable models.)

 

 

Partial loss of charge in thermo-

Replace thermostat.

 

stat bulb causing a wide differ-

 

 

ential.

 

PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

Switches from cooling

Thermostat sticking.

Change room thermostat.

to heating.

Incorrect wiring.

Refer to appropriate wiring diagram.

 

 

 

PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

 

 

 

Evaporator drain pan cracked or

Repair, clean or replace as required.

 

obstructed.

 

Outside water leaks.

Water in compressor area.

Detach shroud from pan and coil. Clean and remove old

 

sealer. Reseal, reinstall and check.

 

 

 

Obstructed condenser coil.

Steam clean.

 

Fan blade and slinger ring

Adjust fan blade 3/16 to 1/4" from condenser shroud.

 

improperly positioned.

Adjust fan motor mount to allow 3/16 to 1/4" clearance

 

 

between condenser fan blade and base pan.

 

 

 

PROBLEM

POSSIBLE CAUSE

TO CORRECT

 

 

 

 

Insufficient air circulation in air

Adjust louvers for best possible air circulation.

 

conditioned area.

 

High indoor humidity.

Oversized unit.

Operate in "Fan-Auto(Moneysaver)" position.

Inadequate vapor barrier in

Advise customer.

 

 

building structure, particularly

 

 

floors.

 

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