T-372
4–44
AL259
Heat Termination Thermostat (HTT) Open
Cause:
Heat Termination Thermostat (HTT) is open.
Component
Heat Termination Thermostat (HTT)
Troubleshooting
Check resistance between CA21 and CA10. If 0 ohms, switch closed. if
infinite (OL), switch open.
Corrective Action
Replace HTT if defective. See Sensor Replacement
AL260
Defrost Temperature Sensor (DTS) Fault
Cause:
Failure of the Defrost Temperature Sensor (DTS) to open.
Component
Defrost Temperature Sensor (DTS)
Troubleshooting
Test the DTS; refer to Sensor Checkout Procedure
.
Corrective Action
Replace the DTS if defective. See Sensor Replacement
.
AL261
Improper Heater Current Fault
Cause:
Improper current draw during heat or defrost mode.
Component
Heater(s)
Troubleshooting
While in heat or defrost mode, check for proper current draw at heater
contactors. See Electrical Data,
.
Corrective Action
Replace heater(s) if defective. See Evaporator Heater Removal and
Replacement
Component
Contactor
Troubleshooting
Check voltage at heater contactor on the heater side.
Corrective Action
If no voltage present, replace heater contactor if defective.
AL263
Exceed Current Limit Setting
Cause:
Unit operating above current limit.
Component
Refrigeration System
Troubleshooting
Check unit for air flow restrictions.
Corrective Action
Clean or remove any debris from coils.
Troubleshooting
Check unit for proper operation.
Corrective Action
Repair as needed.
Component
Power supply
Troubleshooting
Confirm supply voltage / frequency is within specification and balanced
.
Corrective Action
Correct power supply.
Component
Current limit set too low
Troubleshooting
Check current limit setting with function code Cd32.
Corrective Action
The current limit can be raised (maximum of 23 amps) using Cd32.
AL264
Discharge Temperature Sensor (CPDS) Fault
Cause:
Discharge Temperature Sensor (CPDS) out of range.
Component
Discharge Temperature Sensor (CPDS).