The NT133-3 is a complete and simple unit, for a sophisticated temperature control of HV and MV Oil power transformers. With a single device you can control the oil temperature, you can drive the cooling system and you can calculate the thermal image of the 3 windings with exclusive algorithm. The unit is equipped with 1 double Pt100 input for a redundant control and 3 universal inputs for current transformers (CT). Output relays are available for: ALARM, TRIP, FAN cooling system driving, oil circulation PUMP control and FAULT indication. The unit is also equipped with Modbus RS485 output for remote control functions.