A description is given of field-test methods that will ensure that the current transformers used as a source of relay input current are connected properly, are of marked ratio and polarity, and are in condition to perform as designed both initially and after a period of service. The standard covers safety considerations; current transformer types and construction and the effect of these on test methods; insulation resistance tests; ratio tests; polarity check; winding and lead resistance (internal resistance); excitation tests; burden measurements; and specialized situations.
Working Group Details
IEEE Guide for Field Testing of Relaying Current Transformers
This guide describes field test methods that assure that current transformers are connected properly, are of marked ratio and polarity, and are in a condition to perform as designed both initially and after having been in service for a period of time.