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28.0 Troubleshooting Air Cooled Packaged Modules
ASPX modules use the Carel PCO3 master control. The user manual for the PCO3 controller is located in section 6 of the submittal package. The user manual
details the different status screens and explanations of system or module faults. The following guide is for troubleshooting ASPX modules and the PC03.
FAULT
SOLUTION
No Display on Master Module
Check main disconnect for power
Check circuit breakers in module
Check transformer in modules
Check for 24V at J1 on board
EX 1,2, Interlock
Check appropriate interlock component
Check jumpers on TS2 in master module
EX 4 Interlock
Check for proper rotation, phasing
Check PPM device
Waiting For Chilled Water Flow
Check CHW pump
Check flow switch operation
Check filter strainers
Check TS2 inputs #3 - #5
Low Chilled Water Temp
Check LCHW sensor
Check setpoints in system variables
Check for flow restriction
No Demand
Check entering ECHW sensor
Check setpoints in system variables
Check sensor location
100% Demand all the time
Check entering CHW sensors
Check setpoints in system variables
100% Demand, won’t load
Command On at master Control
Check
sensors
Check load limit setting in system variables
Excessive Cycling
Check VSP setting is system variables
Check entering CHW sensor location
High Discharge Pressure (HP)
Check fan operation
Check coil condition
Check fan settings in system variables
Low Suction Pressure (LP)
Check refrigerant charge / leaks
Check expansion valve
Low Suction Temperature
Check suction sensor
Check setpoints in system variables
Check for flow restriction
Communication Error
Check settings in system variables
Check cables at J11 comm ports
Check dip switch settings
Circuit Fault
Check components in control circuit
Check wire crimps in control circuit
P Lan Error
Check the communication circuit (J11) for loose connections
Check for possible airwave interference
