The Vanguard TRM-403 Transformer Resistance Meter is a three phase transformer winding resistance meter that allow the user to connect all test cables to the transformer bushings.

The Vanguard TRM-403 Transformer Resistance Meter will then measure the transformer resistance value for each of the phases without the need to disconnect and reconnect cables for each phase.

The Vanguard TRM-403 Transformer Resistance Meter can provide a fast and stable reading of very large transformers by utilizing a 60Vdc power supply.

The Vanguard TRM-403 Transformer Resistance Meter is capable of outputting a selectable test current from 1A to 40A. Since the Vanguard TRM-403 Transformer Resistance Meter can accurately measure resistance from 1 micro-ohm to 500 Ohms, it can be used as a micro-ohm meter to measure EHV circuit breaker contact resistance, or for any low resistance measuring application.