In secondary injection tests, the protective relay is first disconnected from its normal voltage or current terminal, and is connected to a secondary injection test unit that is capable of injecting as well as recording the operating signal. This signal is fed directly into the protective device or relay to cause the subsequent operation of the circuit breaker.
Secondary injection tests are generally preferred as there is no need for the circuit breaker to interrupt large current and only voltage signals that are sufficiently low are injected into the device.
The Eaton Cutler Hammer 140D481G03 Secondary Injection Test Set is used to test and verify the pickup levels and time delay settings of a breaker’s trip unit. The Eaton Cutler Hammer 140D481G03 is also used to test Amptector, Digitrip, RMS or Optim trip units.
The Eaton Cutler Hammer 140D481G03 passes enough current to check any desired calibration point, allowing the solid-state trip unit operation to be checked without using primary current. The breaker must be de-energized before checking the operation of the solid-state trip units. If the Eaton Cutler Hammer 140D481G03 Secondary Injection Test Set shows that the solid-state trip unit is not functioning properly, the trip unit should be replaced.