• Terms and definitions
  • current transformers: An instrument transformer in which the secondary current, under normal operating conditions, is proportional to the primary current and differ in phase from it by an angle which is approximately zero for appropriate directions of connections.
  • Measuring current transformer: A current transformer intended to supply indicating instruments, integrating meters and similar apparatus.
  • Protective current transformer: A current transformer intended to supply protective relays.
  • Accuracy class: A designation assigned to a current transformer error which remains within specified limits under prescribed operating conditions.
  • Rated output: The value of the apparent power (in V A at a specified power factor) which the transformer is intended to supply to the secondary circuit at the rated secondary current and with rated burden connected to it.