McQuay seasoncon ALP-067A, Установка и техническое обслуживание

Страница: 42 / 50

Trouble Shooting Chart
PROBLEM POSSIBLE CAUSES POSSIBLE CORRECTIVE STEPS
1. Main switch open. 1. Close switch.
2. Fuse blown. Circuit breakers open. 2. Check electrical circuits and motor winding for shorts
or grounds. Investigate for possible overloading. Re-
place fuse or reset breakers after fault is corrected.
3. Thermal overloads tripped. 3. Overloads are auto. reset. Check unit closely when
Compressor will
unit comes back on line.
not run
4. Defective contactor or coil. 4. Repair or replace.
5. System shut down by safety devices. 5. Determine type and cause of shutdown and correct it
before resetting safety switch.
6. No cooling required. 6. None. Wait until unit calls for cooling.
7. Liquid line solenoid will not open. 7. Repair or replace coil.
8. Motor electrical trouble 8. Check motor for opens, short circuit, or burn out.
9. Loose wiring. 9. Check all wire junctions, Tighten all terminal screws.
I. Flooding of refrrgerant Into crankcase. 1. Check setting of expansion valve.
Compressor noisy 2. Improper piping support on suction or 2. Relocate, add or remove hangers.
or vibrating liquid line.
3. Worn compressor 3. Replace.
1.
Non-condensibles in system.
I.
Purge the non-condensibles.
High Discharge
2. System overcharged with refrigerant. 2. Remove excess.
Pressure
3. Discharge shut off valve partially closed. 3. Open valve.
4. Seasontrol out of adjustment 4. Adjust Seasontrot valves.
5. Fan not running. 5. Check belts and electrical
Faulty condenser temperature regulation. Check condenser control operation.
2. Suction shut-off valve partially closed. 2. Open valve.
Low Discharge 3. insufficient refrrgerant in system. 3. Check for leaks. Repair and add charge.
Pressure 4. Low suction pressure. 4. See Corrective Steps for low suction pressure below.
5. Compressor operating unloaded. 5. See Corrective Steps for failure of compressor to load
up below.
1. Excessive load.
Reduce load or add additional equipment.
High Suction 2. valve
2. Check remote bulb. Regulate superheat.
Pressure 3. Compressor unloaders open. 3. See Corrective Steps below for failure of compressor
to load up.
1. Lack of refrigerant. Check for leaks. Repair and add charge.
2. Evaporator dirty. Plugged filters. 2. Clean
3. Clogged filterdrier. 3. Replace cartridge(s).
Low Suction
4. Clogged suction line or compressor suction. 4. Clean
Pressure
gas strainers.
5. Expansion valve malfunctioning. 5. Check and reset for proper superheat.
6. Condensing temperature too low. 6. Check means for regulating condensing temperature.
7. Compressor will not unload. 7. See
Steps for failure of compressor to
unload.
Compressor will not 1. Defective control. Replace.
unload or load up. 2. Pressurestat not set for application. 2. Reset pressurestat setting to fit
1. Clogged suction oil strainer. 1. Clean.
2. Excessive liquid crankcase. 2. Check crankcase heater. Reset expansion valve for
higher superheat. Check liquid line solenoid valve
operation.
3. Oil pressure gauge defective. 3. Repair or replace. Keep valve closed except when
taking readings.
Little or no oil
4. Low oil pressure safety switch defective. 4. Replace.
pressure
5. Worn pump. 5. Replace.
6. Oil pump reversing gear stuck in wrong 6. Reverse of compressor rotation.
position.
7. Worn
7. Replace compressor.
8. Low oil level. 8. Add oil.
9. Loose fitting on oil lines. 9. Check and tighten system.
10. Pump housing gasket leaks. 10. Replace gasket.
11. Flooding of refrigerant into crankcase. 11. Adjust thermal expansion valve.
Compressor loses 1. Lack of refrrgerant.
Check for leaks and repair Add refrigerant.
oil 2. Excessive compression ring blow-by. 2. Replace compressor.
1. Low voltage during high load conditions. 1. Check supply voltage for excessive
drip.
2. Defective or grounded wring in motor. 2. Replace compressor motor.
3. Loose power wiring.
Motor overload
3. Check all connections and tighten.
4. High temperature. 4. See Corrective Steps for high discharge pressure.
relays or circuit 5. Power line fault causing unbalanced voltage. 5. Check supply voltage. Notify power compnay. Do not
breakers open start until fault is corrected.
6. High ambient temperature around the 6. Provide ventilation to reduce heat.
load relay.
7. Failure of second starter to pull in on
7. Repair or replace starter or time delay mechanism.
winding start systems.
Compressor thermal
protector switch
open.
1. Operating beyond design conditions.
2. Discharge valve partially shut.
3. Blown valve plate gasket.
I. Add facilities so that conditions are within allowable
limits.
2. Open valve.
3. Replace gasket.
page 42