Issue:
Full function test kit shows ground fault regardless of the test being performed
Product Line:
Molded Case and Air Circuit Breakers
Resolution:
This is because of the way the FFTK tests the trip unit. The FFTK detects a trip by the drop in supply voltage (since the trip unit diverts it all to the trip solenoid). With PI testing, as with in-service, when the breaker trips, the signal goes away and the indication is correct. But with the FFTK, the test signal can still be applied after the trip unit initially sends the trip signal causing multiple protection functions to react. The Ig light is last to react and therefore is the light that is latched on.
If the FFTK says the breaker passes, it passes.
Full function test kit shows ground fault regardless of the test being performed
Product Line:
Molded Case and Air Circuit Breakers
Resolution:
This is because of the way the FFTK tests the trip unit. The FFTK detects a trip by the drop in supply voltage (since the trip unit diverts it all to the trip solenoid). With PI testing, as with in-service, when the breaker trips, the signal goes away and the indication is correct. But with the FFTK, the test signal can still be applied after the trip unit initially sends the trip signal causing multiple protection functions to react. The Ig light is last to react and therefore is the light that is latched on.
If the FFTK says the breaker passes, it passes.
Released for: Schneider Electric Canada
