Preparation for Primary Injection Tests

The preparation for primary injection does not perform any test. It prepares the circuit breaker for doing the primary injection tests and fulfills preconditions before the actual test is performed.

Reset thermal memory: Thermal memory is a function that models temperature of the cables that are connected to the circuit breaker after a tripping event. This function causes the circuit breaker to trip faster than the published time-current curve, if the wiring had not cooled. Under normal conditions, 15 minutes delay is required following a device tripping to allow the system to cool before returning to normal functionality. The reset thermal memory function inhibits thermal memory, thus overriding the 15 minutes delay and allowing for multiple consecutive primary injection tests.
Inhibit ground fault protection: This function allows a single phase primary injected test current to be applied without causing the circuit breaker to trip on ground fault. It is used when testing the LSI protection functions of the circuit breaker.

NOTE: Ground fault protection option is available when connected to MicroLogic 6.0 A, 6.0 E, 6.0 P, or 6.0 H trip unit.

After performing the above actions, manually connect an external power source on the primary of the circuit breaker to do the test.

NOTE:

The secondary injection testing is the Schneider Electric preferred method for testing circuit breakers. Inappropriate primary injection testing can cause damage to the circuit breakers. Inability to conduct primary injection testing in the proper manner could result in inappropriate test results, while ultimately damaging the integrity of the circuit breaker long term.

For information on secondary injection testing, refer to Automatic Trip Curve Tests.
The circuit breaker is automatically restored to normal mode in 75 minutes, if the test functions are not manually stopped.