Page 8 / SD-324M
8. TROUBLESHOOTING
SYMPTOM
CHECK
Will not power up
Wiring terminals for power at transformer and controller
Supply voltage (see Appendix E - Technical Specifications)
Superheat below setpoint
Pressure Transducer Range (correct transducer set up in controller; 0-300, etc)
Pressure Transducer Type (correct transducer set up in controller; gauge/sealed vs absolute)
Temperature Sensor Type (correct sensor set up in controller; 2K or 3K (see Appendix I - Sensor Installation)
Temperature Sensor wiring (ensure sensor locations are not mismatched)
Foam insulation on piping and sensors
Superheat above setpoint
Liquid condition entering expansion valve
Pressure Transducer Range (correct transducer set up in controller; 0-300, etc)
Temperature Sensor Type (correct sensor set up in controller; 2K or 3K, see Appendix I - Sensor Installation)
EEV (correct valve set up in controller; 1596, 2500 steps, etc)
EEV sizing (if EEV position in controller is at 100% when symptom exists, EEV may be undersized)
Heat exchanger sizing
Proper system refrigerant charge
Oil return (oil logging in heat exchanger)
Liquid line filter (clogging or excessive pressure drop)
No Superheat
Wiring terminals (power) at transformer and controller
Proper system refrigerant charge
Pressure Transducer Range (correct transducer set up in controller; 0-300, etc)
Pressure Transducer Type (correct transducer set up in controller; gauge/sealed vs absolute)
Temperature Sensor Type (correct sensor set up in controller; 2K or 3K (see Appendix I - Sensor Installation)
Temperature Sensor wiring (ensure sensor locations are not mismatched)
Foam insulation on piping and sensors
Superheat unstable
Wiring terminals (power) at transformer and controller
Wiring terminals (sensors) at controller
Sensor locations
Sensor operation (See additional information under Section 8 - Troubleshooting)
Proper heat exchanger flow direction
Stability of head pressure control valves (upstream of EEV)
Stability of suction pressure control valves (downstream of EEV)
Stability of rack controller (verify compressors are not short cycling)
Controller PID setting (See Section 7 - PID Tuning)
No Communication
Wiring at controller and master communication board
Addresses of controllers (see Section 6 - Controller Networking)
Communication errors
Wiring terminals at controller and master communication board
Network wiring from controller to master communication board (see Section 5 - Controller Networking)
Proper network wire grounding (see Section 6 - Controller Networking)
Termination resistors (see Section 6 - Controller Networking)
Network parameters in controller and master communication board (baud rate, parity, etc; see Section 5)
Third-party controllers on Control network
Setpoints not saved
ESC must be set within 60 seconds of changes being made
