Friedrich KS12J30A Air Conditioner User Manual

Friedrich KS12J30A Air Conditioner

Product Information

Specifications/Performance Data

• KS10J10: Straight Cool, Value Series, Approximate BTU/HR (Cooling): 10,000, Voltage: 115 Volts
• KS12J10 : Straight Cool, Value Series, Approximate BTU/HR (Cooling): 12,000, Voltage: 115 Volts
• KS12J30A : Straight Cool, Challenger or QuietMaster Series, Approximate BTU/HR (Cooling): 12,000, Voltage: 230-208 Volts
• KM18J30A : Straight Cool, Challenger or QuietMaster Series, Approximate BTU/HR (Cooling): 18,000, Voltage: 230-208 Volts
• KM21J30 : Straight Cool, Challenger or QuietMaster Series, Approximate BTU/HR (Cooling): 21,000, Voltage: 230-208 Volts
• KL25J30 : Thru-The-Wall, WallMaster Series, Approximate BTU/HR (Cooling): 25,000, Voltage: 230-208 Volts

Components Operation/Testing

The user manual does not provide detailed information about the component’s operation/testing. Please refer to the specific product model’s user manual for more information.

Troubleshooting

The user manual provides troubleshooting information specifically for cooling issues. Please refer to page 15 of the manual for troubleshooting cooling problems.

Wiring Diagrams

The user manual does not provide wiring diagrams. Please refer to the specific product model’s user manual for wiring diagrams.

Parts List

The user manual does not provide a parts list. Please refer to the specific product model’s user manual for a parts list.

Product Usage Instructions

Application and Sizing

In order to properly size and select the appropriate room air conditioner for cooling, it is important to consider all factors that contribute to the heat loss or gain of the space. Follow these steps:

1. Survey the space to be conditioned and calculate the load requirements.
2. Use the AHAM Load Calculating Form provided on page 6 of the manual.
3. Insert the proper measurements on the form and multiply by the given factors.
4. Add the results for the total load requirements.

Instructions for Using Cooling Load Estimate Form for Room Air Conditioners

Follow these instructions to use the AHAM cooling load estimate form:

1. This form is suitable for estimating the cooling load for comfort air conditioning installations that do not require specific conditions of inside temperature and humidity.
2. The form includes day factors for calculating cooling loads in rooms where daytime comfort is desired (such as living rooms, offices, etc.).
3. Multiply the total length (linear feet) of all inside walls between the space to be conditioned and any unconditioned spaces by the given factor. Do not include inside walls that separate other air-conditioned rooms.

FAQ

• Q: Where can I find wiring diagrams for my specific model?
  • A : The user manual does not provide wiring diagrams. Please refer to the specific product model’s user manual for wiring diagrams.
• Q: How can I troubleshoot cooling issues?
  • A : Please refer to page 15 of the manual for troubleshooting cooling problems.

FRIEDRICH ROOM MODEL NUMBER CODE

APPLICATION AND SIZING

In the application and sizing of room air conditioners for cooling, it is most important to give full consideration to all factors that may contribute to the heat loss or gain of the space to be conditioned. It is therefore necessary to make a survey of the space to be conditioned and calculate the load requirements before a selection of the size of the equipment needed can be made.

The load requirement may be determined very easily by simply using the standard “AHAM” Load Calculating Form, on . This form is very easy to use and is self-explanatory throughout. It is necessary only to insert the proper measurements on the lines provided and multiply by the given factors, then add the result for the total load requirements.

Cooling load requirements are generally based on the cooling load for comfortable air conditioning which does not require specific conditions of inside temperature and humidity. The load calculation form is based on outside design temperatures of 95° FDB and 75° FWB. It can be used for areas in the Continental United States having other outside design temperatures by applying a correction factor for the particular locality as determined from the map shown on.
.

When sizing a TwinTemp unit for cooling and heating, we must remember that the heating capacity of any given unit varies directly with the outdoor ambient temperature. Also, we must keep in mind the average low temperatures that might be experienced in the locality where the unit is to be installed. Therefore, when sizing a TwinTemp unit, both cooling and heating requirements must be calculated. Do not oversize, or undersize, one phase of the unit’s capacity at the expense of the other. In those cases where the unit will provide satisfactory cooling at all times but will be inadequate for those few times that the outdoor temperature is below the maximum low for the unit, additional auxiliary heating facilities must be provided to ensure that adequate heat is available at all times.

INSTRUCTIONS FOR USING COOLING LOAD ESTIMATE
FORM FOR ROOM AIR CONDITIONERS
(AHAM PUB. NO. RAC-1)

• A. This cooling load estimate form is suitable for estimating the cooling load for comfort air conditioning installations which do not require specific conditions of inside temperature and humidity.
• B. The form is based on an outside design temperature of 95°F dry bulb and 75°F wet bulb. It can be used for areas in the continental United States having other outside design temperatures by applying a correction factor for the particular locality as determined from the map.
• C. The form includes “day” factors for calculating cooling loads in rooms where daytime comfort is desired (such as living rooms, offices, etc.)
• D. The numbers of the following paragraphs refer to the corresponding numbered item on the form:
• 1. Multiply the square feet of window area for each exposure by the applicable factor. The window area is the area of the wall opening in which the window is installed. For windows shaded by inside shades or venetian blinds, use the factor for “Inside Shades.” For windows shaded by outside awnings or by both outside awnings and inside shades (or venetian blinds), use the factor for “Outside Awnings.” “Single Glass” includes all types of single-thickness windows, and “Double Glass” includes sealed airspace types, storm windows, and glass block. Only one number should be entered in the right-hand column for Item 1, and this number should represent only the exposure with the largest load.
• 2. Multiply the total square feet of all windows in the room by the applicable factor.
• 3a. Multiply the total length (linear feet) of all walls exposed to the outside by the applicable factor. Doors should be considered as being part of the wall. Outside walls facing due north should be calculated separately from outside walls facing other directions. Walls that are permanently shaded by adjacent structures should be considered “North Exposure.” Do not consider trees and shrubbery as providing permanent shading. An uninsulated frame wall or a masonry wall 8 inches or less in thickness is considered “Light construction.” An insulated wall or masonry wall over 8 inches in thickness is considered “Heavy Construction.”
• 3b. Multiply the total length (linear feet) of all inside walls between the space to be conditioned and any unconditioned spaces by the given factor. Do not include inside walls that separate other air-conditioned rooms.
• 4. Multiply the total square feet of roof or ceiling area by the factor given for the type of construction most nearly describing the particular application (use one line only.)
• 5. Multiply the total square feet of floor area by the factor given. Disregard this item if the floor is directly on the ground or over a basement.
• 6. Multiply the number of people who normally occupy the space to be air-conditioned by the factor given. Use a minimum of 2 people.
• 7. Determine the total number of watts for light and electrical equipment, except the air conditioner itself, that will be in use when the room air conditioning is operating. Multiply the total wattage by the factor given.
• 8. Multiply the total width (linear feet) of any doors or arches that are continually open to an unconditioned space by the applicable factor.
• NOTE : Where the width of the doors or arches is more than 5 feet, the actual load may exceed the calculated value. In such cases, both adjoining rooms should be considered as a single large room, and the room air conditioner unit or units should be selected according to a calculation made on this new basis.
• 9. Total the loads estimated for the foregoing 8 items.
• 10. Multiply the subtotal obtained in item 9 by the proper correction factor, selected from the map, for the particular locality. The result is the total estimated design cooling load in BTU per hour.
• E. For best results, a room air conditioner unit or units having a cooling capacity rating (determined in accordance with the NEMA Standards Publication for Room Air Conditioners, CN 1-1960) as close as possible to the estimated load should be selected. In general, a greatly oversized unit that would operate intermittently will be much less satisfactory than one that is slightly undersized and which would operate more nearly continuously.
• F. Intermittent loads such as kitchen and laundry equipment are not included in this form.

COOLING LOAD ESTIMATE FORM

SPECIFICATIONS

PERFORMANCE DATA

COMPONENTS OPERATION & TESTING

WARNING
DISCONNECT ELECTRICAL POWER TO UNIT BEFORE SERVICING OR TESTING

COMPRESSORS

Compressors are single phase, 15 or 230/208 volt, depending on the model unit. All compressor motors are permanent split capacitor type using only a running capacitors across the start and run terminal.
All compressors are internally spring-mounted and externally mounted on rubber isolators.
COMPRESSOR WINDING TEST (See Figure 1)
Remove the compressor terminal box cover and disconnect wires from the terminals. Using an ohmmeter, check continuity across the following:

1. Terminal “C” and “S” – no continuity – open wind-ing – replace the compressor.
2. Terminals “C” and “R” – no continuity – open wind-ing – replace a compressor.
3. Terminal “R” and “S” – no continuity – open wind-ing – replace the compressor.

Figure 1: Compressor Winding Test

GROUND TEST
Use an ohmmeter set on its highest scale. Touch one lead to the compressor body (clean point of contact as a good connection is a must) and the other probe in turn to each compressor terminal (see Figure 2.) If a reading is obtained, the compressor is grounded and must be replaced.

Figure 2: Typical Ground Test

CHECKING COMPRESSOR EFFICIENCY
The reason for compressor inefficiency is normally due to broken or damaged suction and/or discharge valves, reducing the ability of the compressor to pump refriger-ant gas.
This condition can be checked as follows

1.  Install a piercing valve on the suction and discharge or liquid process tube.

2. Attach gauges to the high and low sides of the system.

3. Start the system and run a “cooling or heating performance test.”
   If the test shows:

   • A. Below normal high-side pressure.
   • B. Above normal low-side pressure.
   • C. Low-temperature difference across the coil.

The compressor valves are faulty – replace the compressor.

THERMAL OVERLOAD (External)
Some compressors are equipped with an external overload which is located in the compressor terminal box adjacent to the compressor body (see Figure 3.)

The overload is wired in series with the common motor terminal. The overload senses both major amperage and compressor temperature. High motor temperature or amperage heats the disc causing it to open and break the circuit to the common motor terminal.

Heat generated within the compressor shell is usually due to:

1. High amperage.
2. Low refrigerant charge.
3. Frequent recycling.
4. Dirty condenser.

THERMAL OVERLOAD – TEST (Compressor – External Type)

1. Remove overload.
2. Allow time for overload to reset before attempting to test.
3. Apply ohmmeter probes to terminals on overload wires. There should be continuity through the overload.

TERMINAL OVERLOAD (Internal)
Some model compressors are equipped with an internal overload. The overload is embedded in the motor windings to sense the winding temperature and/or current draw. The overload is connected in series with the common motor terminal.

Should the internal temperature and/or current draw become excessive, the contacts in the overload will open, turning off the compressor. The overload will automatically reset, but may require several hours before the heat is dissipated.
CHECKING THE INTERNAL OVERLOAD
(see Figure 4.)

1. With no power to the unit, remove the leads from the compressor terminals.
2. Using an ohmmeter, test continuity between terminals C-S and C-R. If not continuous, the compressor overload is open and the compressor must be replaced.

FAN MOTOR

A single-phase permanent split capacitor motor is used to drive the evaporator blower and condenser fan. A self-resetting overload is located inside the mo- tor to protect against high temperature and high amperage conditions.

FAN MOTOR – TEST

1. Determine that the capacitor is serviceable.

2. Disconnect fan motor wires from the fan speed switch or system switch.

3. Apply “live” test cord probes on the black wire and com-mon terminal of the capacitor. The motor should run at high speed.

4. Apply “live” test cord probes on the red wire and the com-mon terminal of the capacitor. The motor should run at a low speed.
   

5. Apply “live” test cord probes on each of the remaining wires from the speed switch or system switch to test intermediate speeds.

CAPACITOR, RUN

A run capacitor is wired across the auxiliary and main winding of a single- phase permanent split capacitor motor such as the compressor and fan motor. A single capacitor can be used for each motor or a dual-rated capacitor can be used for both.
The capacitor’s primary function is to reduce the line current while greatly improving the torque characteristics of a motor. The capacitor also reduces the line current to the motor by improving the power factor of the load. The line side of the capacitor is marked with a red dot and is wired to the line side of the circuit (see Figure 6.)

CAPACITOR – TEST

1. Remove the capacitor from the unit.
2. Check for visual damage such as bulges, cracks, or leaks.
3. For dual rated, apply an ohmmeter lead to the common (C) terminal and the other probe to the compressor (HERM) terminal. A satisfactory capacitor will cause a deflection on the pointer, then gradually move back to infinity.
4. Reverse the leads of the probe and momentarily touch the capacitor terminals. The deflection of the pointer should be two times that of the first check if the capacitor is good.
5. Repeat steps 3 and 4 to check the fan motor capacitor.

NOTE : A shorted capacitor will indicate a low resistance and the pointer will move to the “0” end of the scale and remain there as long as the probes are connected.
An open capacitor will show no movement of the pointer when placed across the terminals of the capacitor.

SYSTEM CONTROL SWITCH
A five-position control switch is used to regulate the operation of the fan motor and compressor. The compressors can be operated with the fan operating at low, medium or high speed. The fan motor can also be operated independently on medium speed. See the switch section as indicated on a decorative control panel (see Figure 7.)
SYSTEM CONTROL SWITCH – TEST
Disconnect leads from the control switch (see Figure 8.) There must be continuity as follows:

1. “Off” Position – no continuity between terminals.
2. “Lo Cool” Position – between terminals “L1” and “C”, “LO” and “MS”.
3. “Med Cool” Position – between terminals “L1” and “C”, “M” and “MS”.
4. “Hi Cool” Position – between terminals “L1” and “C”, “H” and “MS”.
5. “Fan Only” Position – between terminals “L1” and “2”.

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 cool-ing cycle in the event ice forms on the evaporator coil, in this case the thermostat functions as a de-ice control. A resistor (anticipator) is positioned within a plastic block to supply a small amount of heat to the bulb area to prevent long “off cycles” in the “Cool-Fan Auto” (Money-Saver) position (see Figure 10.) A current feedback through the fan motor windings during the “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 the 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 are open.

NOTE : Temperature must be within the range listed to check the thermostat. Refer to the troubleshooting section in this manual for additional information on thermostat testing.

THERMOSTAT ADJUSTMENT

No attempt should be made to adjust the 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.

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

MONEYSAVER® SWITCH
(Rocker Switch) – (See Figure 11)

This rocker switch can be depressed to either YES or NO. In the YES 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 the NO position, the fan will run constantly as long as the unit is in the cooling mode.
TEST:
Disconnect leads from the 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”.

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-6 or equivalent.)
8. Accurate refrigerant charge measuring devices 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. 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 the 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 CFCs in the system to at least 5%.
2. Cut the process tube below and 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 sys-tem when making these connections.
6. Pressurize the 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 the vacuum pump to the high side and low side of the system with deep vacuum hoses, or copper tubing. (Do not use regular hoses.)
10. Evacuate the system to a maximum absolute holding pressure of 200 microns or less. NOTE: This process can be speeded up by the 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 the system for a minimum of 10 minutes. Recover refrigerant, and proceed with evaluation of a pressure of 200 microns or a minimum of 10 %.
11. Break the vacuum by charging the system from the high side with the correct amount of refrigerant specified. This will prevent boiling the oil out of the crank case.
12. 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.
13. Restart the 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 MOTOR COMPRESSOR BURNOUT

1. Recover all refrigerant and oil from the system.
2. Remove the compressor, capillary tube, and filter drier from the system.
3. Flush the evaporator condenser and all connecting tubing with dry nitrogen or equivalent, to remove all contamination from the system. Inspect suction and discharge line for carbon deposits. Remove and clean if necessary.
4. Reassemble the system, including a new drier strainer and capillary tube.
5. Proceed with processing as outlined under her-metic component replacement.

ROTARY COMPRESSOR SPECIAL TROUBLESHOOTING AND SERVICE
Basically, troubleshooting and servicing the rotary compressor 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 ensure the correct connection.

REFRIGERANT CHARGE

1. The refrigerant charge is extremely critical. Measure the 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 the 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.

Troubleshooting Cooling

The compressor does not run.

| Low voltage.| Check for voltage at compressor. 1115 volt and 230 volt
 | units will operate at 10% voltage variance.
The thermostat not set cold

enough or inoperative.

| Set the thermostat to the coldest position. Test the thermostat and

replace if inoperative.

The compressor hums but cuts off

on overload.

| Hard start compressor. Direct test compressor. If com-

pressor starts, add starting components.

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

wiring.

| Refer to the appropriate wiring diagram to check the wiring.

The fan motor does not run.

| Inoperative system switch.| Test switch and replace if inoperative.
Broken, loose or incorrect

wiring.

| Refer to the applicable wiring diagram.
Open capacitor.| Test the capacitor and replace it if it inoperative.
Fan speed switch open.| Test switch and replace if inoperative.
Inoperative fan motor.| Test the fan motor and replace it if it is inoperative (be sure the internal

overload has had time to reset).

PROBLEM| POSSIBLE CAUSE| TO CORRECT|
---|---|---|---

Does not cool, or cools only slightly.

| Undersized unit.| Refer to Sizing Charts.
Thermostat open or inopera-

tive.

| Set to coldest position. Test the thermostat and replace if

necessary.

Dirty filter| Clean as recommended in the Owner’s Manual.|
Dirty or plugged condenser or

evaporator coil.

| Use steam or detergents to clean.|
Pool air circulation in the area

being cooled.

| Adjust discharge air louvers. Use high fan speed.|
Fresh air or exhaust air door

open on applicable models.

| Close doors. Instruct customer on use of this feature.|
Low capacity – undercharge.| Clean for leaks and make repair.
Compressor not pumping

properly.

| Check amperage draw against nameplate. If not conclude-

sive, make pressure test.

Unit does not run.

| Fuse blown or circuit tripped.| Replace fuse, and reset the breaker. If repeats, check the fuse or breaker size. Check for shorts in unit wiring and components
Power cord is not plugged in.| Plug in power cord
System switch in “Off” position.| Set the switch correctly.
Inoperative system switch.| Test for continuity in each switch position.
Loose or disconnected wiring at

switch or other components

| Check wiring and connections. Reconnect per wiring

diagram.

Evaporator coil freezes up.

| Dirty filter.| Clean as recommended in Owener’s Manual.
Restricted air flow.| Check for dirty or obstructed coil – clean as required.
Inoperative thermostat.| Test for shorted thermostat or stuck contacts.
Short of refrigerant.| De-ice coil and check for leak.
Inoperative fan motor.| Test fan motor and replace if inoperative.
Partially restricted capillary.| De-ice coil. Check temperature differential across the coil.

Touch test coil return bends for the same temperature. Test for low running current.

The compressor runs continually. Does not cycle off.

| Excessive heat load.| Unit undersized. Test the cooling performance of the unit. Re-place with a larger unit.
Restriction in line.| Check for the partially iced coil. Check temperature split

across coil.

Refrigerant leak.| Check for oil at silver-soldered connections. Check for the partially iced coil. Check split across the coil. Check for low

running amperage.

The thermostat contacts stuck.| Check the operation of the thermostat. Replace if contacts remain

closed.

A thermostat is incorrectly wired.| Refer to the appropriate wiring diagram.

setting to see if the unit

cycles off.

Incorrect wiring.| Refer to the appropriate wiring diagram.
Unit undersized for the area to be

cooled.

| Refer to the Sizing Chart.

Compressor attempts to start, or runs for short periods only. Cycles on overload.

| Overload inoperative. Opens too soon.| Check operation of unit. Replace overload if system operation is satisfactory.
Compressor attempts to start

before system pressures are equalized.

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

equalize before attempting to restart. Instruct customer of waiting period.

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 the appropriate wiring diagram.
Shorted or incorrect capacitor.| Check by substituting a known good capacitor of the correct

rating.

Restricted or low air flow through

condenser coil.

| Check for proper fan speed or blocked condenser.
Compressor running abnormally

hot.

| Check for a kinked discharge line or restricted condenser.

Check amperage.

The thermostat does not turn the unit on.

| Loss of charge in thermostat bulb.| Place the jumper across thermostat terminals to check if the unit operates. If the unit operates, replace the thermostat.
Loose or broken parts in thermo-

stat.

Incorrect wiring.

| Check as above.
Refer to the appropriate wiring diagram.
PROBLEM| POSSIBLE CAUSE| TO CORRECT
---|---|---

Noisy operation.

| Poorly installed unit.| Refer to Installation Instructions for proper installation.
Fan blade striking chassis.| Reposition – adjust motor mount.
Compressor vibrating.| Check that compressor grommets have not deteriorated.
Improperly mounted or loose

cabinet parts.

| Check that compressor mounting parts are not missing.
PROBLEM| POSSIBLE CAUSE| TO CORRECT
---|---|---

Water leaks into the room.

| Evaporator drain pan overflowing.| Clean obstructed drain trough.
Condensation forming on the base

pan.

| The evaporator drain pan is broken or cracked. Reseal or replace.
The poor installation resulted in rain

entering the room.

| Check installation instructions. Reseal as required.
Condensation on discharge

grilles.

| Dirty evaporator coil – clean. Very high humidity level.
PROBLEM| POSSIBLE CAUSE| TO CORRECT
---|---|---

Thermostat short cycles.

| The thermostat differential is too narrow.| Replace thermostat.
The plenum gasket not sealing,

allowing discharge air to short-cycle the thermostat.

| Check the gasket, reposition, or replace it.
Restricted coil or dirty filter.| Clean and advise customers of periodic cleaning of the filter.
Thermostat bulb touching

thermostat bulb support bracket.

| Adjust the bulb bracket.

(Applicable models.)

Prolonged off cycles (automatic operation).

| The anticipator (resistor) wire is disconnected at the thermostat or system switch.| Refer to the appropriate wiring diagram.
Anticipator (resistor shorted or

open).

(Applicable models.)

| Replace thermostat block and resistor.
Partial loss of charge in thermo-

stat bulb causing a wide differential.

| Replace thermostat.
PROBLEM| POSSIBLE CAUSE| TO CORRECT
---|---|---
Switches from cooling to heating.| Thermostat sticking.| Change room thermostat.
Incorrect wiring.| Refer to the appropriate wiring diagram.
PROBLEM| POSSIBLE CAUSE| TO CORRECT
---|---|---

Outside water leaks.

| The evaporator drain pan cracked or obstructed.| Repair, clean, or replace as required.
Water in compressor area.| Detach shroud from pan and coil. Clean and remove the old

sealer. Reseal, reinstall, and check.

Obstructed condenser coil.| Steam clean.
Fan blade and slinger ring

improperly positioned.

| Adjust the fan blade 3/16 to 1/4″ from the condenser shroud.

Adjust the fan motor mount to allow 3/16 to 1/4″ clearance between the condenser fan blade and base pan.

High indoor humidity.

| Insufficient air circulation in air-conditioned areas.| Adjust louvers for best possible air circulation.
Oversized unit.| Operate in the “Fan-Auto (Moneysaver)” position.
Inadequate vapor barrier in

building structure, particularly floors.

| Advise customer.

WIRING DIAGRAM

QUIETMASTER “KS” – “KM” SERIES CHASSIS PARTS

QUIETMASTER “KS” – “KM” SERIES CABINET PARTS

QUIETMASTER “KS” . “KM” SERIES PARTS LIST

QUIETMASTER “KS” – “KM” SERIES PARTS LIST

QUIETMASTER “KS” ” “KM” SERIES PARTS LIST

QUIETMASTER “KL” SERIES CHASSIS PARTS

QUIETMASTER “KL” SERIES CABINET PARTS

QUIETMASTER “KL” SERIES PARTS LIST

QUIETMASTER “KL” SERIES PARTS LIST

Use Factory
Certified Parts . . .

• Friedrich Air Conditioning Co.
• 4200 North Pan Am Expressway
• P.O. Box 1540
• San Antonio, Texas 78295-1540
• U.S.A.
• Phone : 210-357-4400
• Fax : 210-357-4480

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