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