The High Temp Alarm is triggered when the indoor temperature exceeds temperature setpoint + high temp alarm trigger (default = 16°F). This alarm has a built in 1-minute delay, which can be changed at F35 under L05 Menu if using the PLD or at P8 in the User Menu if using the PGD.
Troubleshooting
| Possible Cause | Component to Check | Recommended Action |
| Reduced cooling capacity | Filter, condenser coil, low side pressure. | Clean/wash filter and condenser. Remove blockage if appropriate. Leak check/ repair if low on refrigerant. |
| Improper value set for high temp alarm trigger | Ht under E menu or other thermostat used to monitor high temperature If using the pGD, this parameter can be accessed from User Menu – P8 | Default = 18°F above the main setpoint. |
| Undersized unit | Check if the heat load of the site exceeds sensible capacity of the AC units | Add/Upgrade AC or reduce heat load by turning off unused equipment |
| Cooling command not given by controller | Check for other alarms present on controller. Use D52/D57 under C Menu to view current compressor command for unit1/unit2 respectively | Correct other alarms that would prevent compressor start up, such as high/low pressure lockout and smoke/fire alarm. |
| Improper value set for compressor turn on | Lead compressor turn on: C02 under E menu Lag compressor turn on: F38 under L05 Menu If using the pGD, these parameter can be accessed under User Menu. | Correct compressor settings. |
| Compressor circuit failure | Compressor. Compressor contactor (KM1) Compressor run caps (C) Compressor circuit wiring | Replace failed component. Correct/tighten wiring according to the Compressor Circuit diagram. |
| Indoor temperature sensor | Indoor temp sensor (ST1) Indoor temp sensor calibration (N2A under C menu) Backup Indoor temp sensor (ST2) Backup indoor temp sensor calibration (N42 under C Menu) If using the pGD, calibrations can be accessed in Maintenance Menu | Verify sensor operation. Correct calibration. |
Compressor Circuit
