What is instrument transformers?

Instrument transformers are high-accuracy electrical devices used to isolate or transform voltage or current levels. They are commonly used to operate metering and protection equipment from high-voltage or high-current power systems, isolating control circuitry from the high voltages or currents. A current transformer (CT) transforms high currents to a lower value, while a voltage transformer (VT), also known as a potential transformer (PT), transforms high voltages to a lower value. These lower values are then used by protective relays, metering equipment and control systems.