FIGURE 13. TROUBLESHOOTING GUIDE - CURRENT CONTROL PANEL
MOTOR TEMPERATURE
0
0
0
0
OIL TEMPERATURE
1. On/Off switch.
2. Disconnect or breaker open
3. Control circuit fuse blown.
1. Motor starter problem.
2. Loss of refrigerant.
3. Motor cooling feed problem
4. Low voltage.
5. Single phasing
6. Faulty R1 relay.
7. Faulty Guardrstor diode.
8. Open thermstor.
9. Faulty Guardrstor relay.
10. Unbalanced voltage.
1. Vane closed switch not closed.
2. Vane closed switch defective.
3. Oil pump Failure
4. Faulty R2 relay.
5. OTD relay malfunction.
6. Oil line valves closed.
7. Oil filter plugged.
8. Oil cooler malfunction.
9. Low o i l pressure
10. Faulty o i l differential
switch
1. Faulty oil cooler solenoid.
2. Plugged o i l cooler water strainer.
3. Service valve partially closed.
4. Low refrigerant charge.
5. High coolant temperature
6. Plugged refrigerant filter-drier.
7. Oil heater.
8. Faulty switch.
9. Loosely mounted bulb.
10. Leaking oil cooler solenoid.
11. Switch setting wrong.
1. Loss of refrigerant.
2. Restricted refrigerant flow.
3. Expansion valve malfunction.
4. Faulty liquid solenoid valve.
5. Fault pumpdown switch.
6. Compressor not unloading.
7. Low condenser water temperature
8. Restricted evaporator water flow.
9. Excessive oil in system.
1. Switch position.
2. Check breaker or disconnect.
3. Fuse size, check for ground or
control circuit short
1. Measure motor winding
resistance.
2. Leak test, check charge
3. Filter-drier plugged
4. Measure supply voltage; include
wire size voltage drop.
5. Motor fuses, incoming power
lines.
6. Relay action.
7. Check diode
8 Thermistor resistance.
9. Interchange Surgegard and
Guardrstor relays.
10. Measure phase voltages.
1. Vane closing speed
2. Switch contacts.
3. O i l pump.
4. Relay action.
5. Relay action.
6. Valve positron
7. Oil pressure drop.
8. Feed oil lines for temperature.
9a. Pump.
b. Relief valve.
c. Filter.
d. Bearings and seals.
10. Opening, closing pressure.
1. Check solenoid valve and coil.
2. If water cooled, check strainer.
3. Check valve positron.
4. Check for leaks.
5. Check refrigerant flow, or if
water cooled, water temperature.
6. Check pressure drop
7. Check for faulty heater
8. Switching action.
9. Bulb mounting.
10. Check solenoid closing
11. Check switch setting.
1. Compressor suction superheat.
2. Check for unusual pressure d r o p .
3. Manually operate valve
4. Liquid valve.
5. Check switch action
6a. Control module.
b. Open sensor.
c. Vane damage.
7. Cooling tower control.
8. Measure flow.
9. Oil level.
1. Turn on.
2. Close.
3. Replace fuse with correct size,
repair grounded item or replace
shorted component.
1. Contact McQuay Service.
2. Repair leak, add refrigerant.
3. Replace core or drier.
4. Increase supply voltage, replace
wire, tighten lugs.
5. Replace fuse, check operation,
check power company.
6. Replace.
7. Replace diode.
8. Contact McQuay Service
9. Replace defective relay.
10. Tighten electrrcal connections.
1. Adjust vane close speed
2. Replace.
3. Repair or replace.
4. Replace.
5. Repair or replace.
6. Open valves.
7 Change filter.
8 Adjust coolant flow.
9a. Repair, replace
b. Reset.
c. Change filter.
d. Contact McQuay Service.
10. Replace.
1. Replace c o i l and/or valve.
2. Clean or replace strainer.
3. Open valves.
4. Fix leak and charge unit.
5. If water cooled lower water temp-
erature or increase water flow.
6. Replace filter-drier.
7 If faulty, replace.
8. Replace faulty switch.
9. Make good bulb contact.
10. Repair or replace.
11. Adjust switch.
1. Adjust refrigerant charge
2. Remove restriction.
3. Adjust, repair, replace.
4. Repair, replace.
5. Repair, replace.
6a. Calibrate.
b. Replace.
c. Repair.
7. Adjust control.
6. Adjust.
9. Adjust oil charge.
Page 20 / IM 307
