Primary current injection tests are carried out during commissioning and certification of various types of switchgear and current transformers (CT), as well as during diagnostics of grounding circuits, testing circuit breakers and other devices.
Primary current injection testers can also be used for determining the terminals polarity and transformation ratio of current transformers, thermal testing of electrical devices, testing automatic reclosers and sectional disconnectors.
The integrity of grounding circuits and protective earthing devices can be verified by injecting high current between the ground and the circuit under test, followed by the measurement of a voltage percentage drop and the current flowing through the grounding circuit.