FRIEDRICH QUIETMASTER KS12J30A (01) PDF Document

The model number of your FRIEDRICH QUIETMASTER KS12J30A provides specific information about the unit’s features and type. Here is a breakdown of the code:

1st DIGIT – FUNCTION

K = Straight Cool, Challenger or QuietMaster Series

2nd DIGIT – TYPE

S = Small Chassis

3rd & 4th DIGITS – APPROXIMATE BTU/HR (Cooling)

These digits represent the approximate cooling capacity. The heating BTU/HR capacity is listed in the Specifications/Performance Data Section.

5th DIGIT – ALPHABETICAL MODIFIER

This is an alphabetical character that acts as a modifier.

6th DIGIT – VOLTAGE

3 = 230-208 Volts

7th DIGIT

0 = Straight Cool & Heat Pump Models

8th DIGIT

This digit signifies a Major Change in the product line.

The performance data for the FRIEDRICH QUIETMASTER KS12J30A, based on rating conditions of 80°F Room Air Temperature and 50% Relative Humidity with 95°F Outside Air Temperature at 40% Relative Humidity, is as follows:

WARNING: DISCONNECT ELECTRICAL POWER TO THE UNIT BEFORE SERVICING OR TESTING.

Compressor Winding Test

1. Remove the compressor terminal box cover and disconnect wires from the terminals.

2. Using an ohmmeter, check for continuity across the following terminals:

Terminal “C” and “S” – no continuity means an open winding, and the compressor must be replaced.

Terminal “C” and “R” – no continuity means an open winding, and the compressor must be replaced.

Terminal “R” and “S” – no continuity means an open winding, and the compressor must be replaced.

Ground Test

1. Use an ohmmeter set on its highest scale.

2. Touch one lead to the compressor body (ensure a clean point of contact for a good connection) and the other probe, in turn, to each compressor terminal.

3. If a reading is obtained, the compressor is grounded and must be replaced.

Compressor inefficiency is typically caused by broken or damaged suction and/or discharge valves, which reduces the compressor’s ability to pump refrigerant gas. To check for this condition:

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 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.

Then the compressor valves are faulty, and the compressor should be replaced.

WARNING: DISCONNECT ELECTRICAL POWER TO THE UNIT BEFORE SERVICING OR TESTING.

Testing an External Overload:

1. Remove the overload.

2. Allow time for the overload to reset before attempting to test.

3. Apply ohmmeter probes to the terminals on the overload wires. There should be continuity through the overload.

Checking an Internal Overload:

1. With no power to the unit, remove the leads from the compressor terminals.

2. Using an ohmmeter, test for continuity between terminals C-S and C-R. If there is no continuity, the compressor’s internal overload is open, and the compressor must be replaced.

WARNING: DISCONNECT ELECTRICAL POWER TO THE UNIT BEFORE SERVICING OR TESTING.

Fan Motor Test:

1. Ensure the capacitor is serviceable before testing the motor.

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

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

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

Run Capacitor Test:

1. Remove the capacitor from the unit.

2. Check for visual damage such as bulges, cracks, or leaks.

3. For dual-rated capacitors, apply an ohmmeter lead to the common (C) terminal and the other probe to the compressor (HERM) terminal. A good capacitor will cause the ohmmeter’s pointer to deflect and then gradually move back to infinity.

4. Reverse the probe leads and momentarily touch the capacitor terminals. The pointer’s deflection should be twice that of the first check if the capacitor is good.

5. Repeat steps 3 and 4 to check the fan motor side of the capacitor.

NOTE: A shorted capacitor will show a low, constant resistance (“0”). An open capacitor will show no movement of the pointer.

WARNING: DISCONNECT ELECTRICAL POWER TO THE UNIT BEFORE SERVICING OR TESTING.

System Control Switch Test:

Disconnect the leads from the control switch. Using an ohmmeter, check for continuity between the terminals for each position:

“Off” Position – no continuity between terminals.

“Lo Cool” Position – continuity between terminals “L1” and “C”, “LO” and “MS”.

“Med Cool” Position – continuity between terminals “L1” and “C”, “M” and “MS”.

“Hi Cool” Position – continuity between terminals “L1” and “C”, “H” and “MS”.

“Fan Only” Position – continuity between terminals “L1” and “2”.

Thermostat Test:

1. Remove the wires from the thermostat.

2. Turn the thermostat to its coldest position and check for continuity between the two terminals.

3. Turn the thermostat to its warmest position and check to see if the thermostat contacts open (no continuity).

NOTE: The temperature must be within the thermostat’s range of 60°F (± 2°) to 92°F (± 4°) for an accurate test. Do not attempt to adjust the thermostat; if it is faulty, it should be replaced.

WARNING: DISCONNECT ELECTRICAL POWER TO THE UNIT BEFORE SERVICING OR TESTING.

To test the MoneySaver® rocker switch, disconnect the leads from the switch and use an ohmmeter to check for continuity.

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”.

This procedure applies when replacing components like the compressor, condenser, evaporator, or capillary tube, or when repairing refrigerant leaks.

1. Recover the refrigerant from the system at the process tube located on the high side of the system using an EPA-approved recovery system. Recover CFCs in the system to at least 5%.

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

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

4. Drift dry nitrogen through the system and unsolder the most distant connection first (e.g., filter drier, high side process tube).

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

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

7. Leak test the complete system with an electronic halogen leak detector and correct any leaks found.

8. Reduce the system pressure to zero gauge pressure.

9. Connect a vacuum pump to both the high and low sides of the system using 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.

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

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

The following tables explain the components in the wiring diagram and the logic for the system switch positions.

LEGEND

SWITCH LOGIC (X = CLOSED, O = OPEN)