The AC drives manufacturer Vacon (VAZ.BE)
has developed an ATEX-certified thermistor input which is fully integrated in the drive. Certified and compliant with ATEX 94/9/EC, the integrated thermistor input is specially designed for the temperature supervision of motors that are placed in potentially hazardous areas. In contrast to a typical system with a separate thermistor relay and contactor, a thermistor input is designed to be fully integrated in the Vacon NXP drive, simplifying the use of drives together with Ex motors, i.e. motors that are designed and certified for use in potentially explosive environments. If extreme temperature is detected, the drive stops feeding energy
to the motor and thus further heating of the motor is avoided. As no external components are needed, the cabling is kept to a minimum. The thermistor input is available for the Vacon NXP drives in the power range of 0.75 kW - 5 MW in voltages 380-500 V and 525-690 V.