Designed to control heating and prevent overheating of the heater and heated air at the outlet in air industrial curtains. Has a function of self-diagnostics of the heating device (serviceable - faulty), the sensor of control of movement of air. When the air flow is reduced by 80%, the heating unit is switched off. It is installed in devices in 220V power supply circuits; 380V three-phase. It has a separate 24V or 12V DC power supply to power the fan.