Plating line fan double-speed energy-saving control system

The utility model provides a double-speed energy-saving control system for a plating line fan. The double-speed energy-saving control system comprises a PIC digital output module, a relay set, a pretreatment fan frequency converter, a fan set module, a point analog quantity input module, a PLC digital output module and a computer terminal. The PIC digital output module generates a starting electric signal, a high-frequency electric signal and a low-frequency electric signal and sends the electric signals to the pre-processing fan frequency converter through the relay set, and the pre-processing fan frequency converter controls the fan set module to operate and sends the electric signals to the point analog quantity input module. The point analog quantity input module sends an electric signal to the PLC digital output module, and the PLC digital output module processes the electric signal and then sends the electric signal to the computer terminal for display. The plating line exhaust fan overcomes the defects