Heatcraft H-IM-QRC, Installation And Operation Manual, Page: 27 / 40

27
Heatcraft Quick Response Controller Troubleshooting Guide (continued)
Diagnostics
PROBLEM Step ACTION ITEM IF OK IF NOT OK
1. Check system operation: Is it running? 1. Check power to condensing unit
Check position of Service Mode switches
Check compressor overloads and contactor
2. Check system charge 2. Add or remove refrigerant to proper charge
3. Check for proper operating superheat 3. Check EEV operation
Check control board EEV signal
Check suction sensor and transducer
4. Check for high superheat and EEV wide open 4. Check EEV inlet screen and restrictions
Check liquid line sizing
Check head pressure controls
5. Check Low Pressure Safety Switch 5. Correctly set or replace if bad
Cannot get to box 6. Compare equipment capacity with requirements 6. Add or replace with more/larger equipment
temperature
7. Check box temperature setpoint 7. Correct setpoint to proper value
8. Check compressor performance 8. Check compressor application limitations
Check integrity of compressor operation
(impaired, worn or damaged components)
9. Check condenser coil for dirt/debris 9. Clean condenser coil
10. Check condenser for non-condensables 10. Remove all non-condensables
11. Check condenser fan operation 11. Replace/repair fan blade, motor, cycling
switch or make corrective adjustments.
12. Check for correct refrigerant type 12. Compare board setpoint and refrigerant
13. Check for iced evaporator coil 13. Defrost coil and check defrost cycle (see E2)
settings/setpoints and defrost sensor
14. Check defrost parameters 14. Correct defrost setpoints in program
(frequency and termination of defrosts)
15. Check superheat setpoint (too high?) 15. Correct setpoint for more cooling surface
16. Check display values (°F or °C) 16. Correct setpoint for proper display values
Placing system into SERVICE MODE Terminating SERVICE MODE
(MASTER BOARDS ONLY) (MASTER BOARDS ONLY)
1. Use Remote Service Switch in condensing unit 1. Must terminate using same switch
2. Pressing “Force Service” button board* twice 2. Press “Clear” button on board
3. Connection between “Ser” and “C” on board* 3. Open connection between “Ser” and “C”
(all are wired in parallel; all will activate mode)
(Note: If multiple switches were placed in Service
*ONLY Master board on multiple evaporator systems Mode, all must be “open” to terminate the mode.)
Service Mode
( SEr is displayed)