ABB: Instrument Transformers

 

An instrument transformer’s role is to provide accurate inputs to protection, control and metering systems including revenue metering.

 

The main tasks of instrument transformers are:

  • To transform currents or voltages from a usually high value to a value easy to handle for relays and instruments.
  • To insulate the metering circuit from the primary high voltage system.
  • To provide possibilities of standardizing the instruments and relays to a few rated currents and voltages.