Cold Room Electronic Controller, Temperature Sensor & Defrost Logic Control

Cold Room Electronic Controller, Temperature Sensor & Defrost Logic Control

Electronic controller is the brain of cold room system; collect temperature and pressure signal, control compressor, fan, solenoid and defrost sequence. Temperature sensor types: NTC thermistor, PT100 platinum resistance; PT100 has higher precision for export high standard project. Room temperature sensor: installed in air return side of air cooler, avoid direct blowing and door opening air impact. Coil temperature sensor: mounted on evaporator fin, judge defrost end point by coil temperature instead of fixed timer only. Defrost control modes: time-initiated + temperature-terminated (the most reliable mode for low temperature cold room). Xiteliduo controller supports Modbus communication, remote cloud monitoring, alarm record and parameter lock function. Common alarm: temperature deviation, sensor open/short circuit, defrost overtime, high/low pressure, low oil protection. Sensor wire cannot run together with high power AC cable; electromagnetic interference causes temperature reading drift. Controller power supply needs stable voltage; voltage fluctuation will lead to mis-trigger of defrost and compressor stop. Refrigeration maintenance & repair company calibrates temperature sensor against precision thermometer periodically.

FAQ

1. What two common temperature sensors for cold room? NTC thermistor and PT100.
2. Where to install cold room return air temperature sensor? Air cooler return air zone, avoid direct airflow.
3. Where is coil sensor fixed? On evaporator fin surface.
4. What is the recommended defrost control logic? Time start, temperature terminate.
5. What communication protocol for remote monitoring? Modbus.
6. What causes temperature reading drift of sensor? EMI interference from nearby high power cable.
7. What is defrost overtime alarm? Defrost runs too long and coil cannot reach end temperature.
8. Why lock controller parameters? Prevent field operator random modification of refrigeration parameters.