Description:
Constant temperature and humidity control cabinet widely used in workshop, exhibition, archives, laboratory, network station.
Our control system for constant temperature and humidity can save much energy,reduced the working time of compressor, extend the working time of facilities. PLC is the key unit in our system,it has good stable, Strong anti-interference ability.The system fixed warm humidity transmitter as digital transmission.long transmission distance, free of electrostatic interference. Control precision.
System hardware structure:
The core of system is Siemens PLC, touch screen as human-computer interface. the temperature and humility transfer by sensor, It is processed into digital signal by single chip, via RS485 wire transfer to PLC, and data processing, and controlled via PID. Keep constant temperature and humility controlling compressor, humidificatin valve,fan valve.
The procedure of control for constant temperature and humid:
There are 5 method from PLC controlling.
1. monitor status. The system only reads the temperature and humidity of the environment,without controlling.
2. Hand control status.when compressor forced operation need hand control.You can touch compressor 1, compressor 2 for start.
3. Automatic humidification, When start this method, the system will work according fixed upperlimit & lowerlimit.
4. Automatic temperature control. When start this method, the system will work according fixed upperlimit & lowerlimit. At the same time, monitor the outdoor temperature is less than 14 ℃
5. Circulation working: combination method 3 & method 4. Temperature controlling then humidification controlling.
