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6. Monitoring and testing
Power XPert® release triP unit for MagnuM PXr circuit breakers
MN013015EN January 2022 www.eaton.com
•
When testing insulation, the voltage sensing circuit will be
seen by a megohmmeter as a very high resistance
(> 6 megaohms) between line and neutral. If your testing
requires eliminating this effect, then test with the breaker
in the racked-out position, there is no voltage disconnect
plug.
•
If you are testing with primary current, the trip unit will
self-power only from the sensors within the breaker
frame. It will not self-power from external neutral or
ground fault sensors.
•
With primary injection, your protection and enhanced
protection settings may trip the breaker. For example,
ground faults or phase loss trips may be generated when
current is applied on individual phases.
•
When testing, a breaker may trip outside of its own
settings because of ZSI signals.
•
Thermal memory, when enabled, will affect trip times
on repeated testing of the same circuit breaker. See
Sections 3.2.1 - Long delay thermal memory and 3.6.3 -
Ground fault thermal memory which explain this behavior.
•
The VDB does not need to be disconnected for high
potential (hi-pot) testing.
