Wound Primary CT

Variant in Current Transformer: Wound Primary CT

A control transformer is a transformer that is used to step down the voltage to power the control devices of a circuit or machine. The reduced voltage provides a much safer environment for technicians working on the equipment. Residential heating, ventilating, air conditioning systems, and other machines use reduced voltage for the controls, thermostats, relays, and contactors.

Control transformers are often referred to as power supplies. Control transformers with two primary coils and one secondary coil are the most common. A control transformer's primary coils are crossed so that metal links can be used to connect the primaries for 240 V or 480 V operation.