Meggering conductors already land on a breaker

[JJWalecka]

If the circuit breaker is off.. is it safe to megger conductors already landed on a breaker. Will it damage the circuit breaker if the circuit breaker is off...

 

[MrJLH]

If the circuit breaker is off.. is it safe to megger conductors already landed on a breaker. Will it damage the circuit breaker if the circuit breaker is off...

I wouldn't do it, voltage from the meggar may damage internal components breaker, and you would probably see some off readings.

I would take the time to determine the breaker.

 

[ptonsparky]

Depends. We have megged load side of standard plug on breakers but I have never thought about doing it on any GFCI or AFCI circuit breaker. Line or load. So it depends.

Having any breaker, starter, switch etc included will change the test results especially on older existing installations.

 

[kwired]

Depends. We have megged load side of standard plug on breakers but I have never thought about doing it on any GFCI or AFCI circuit breaker. Line or load. So it depends.

Having any breaker, starter, switch etc included will change the test results especially on older existing installations.

Ditto. Other than when there is AFCI/GFCI breakers I would be more concerned about what damage I may do to any connected load than any potential damage to a standard breaker. Standard breaker had better be able to handle the test or it has problems.

 

[petersonra]

regular MCCB are designed to be meggered as far as I know.

I doubt a GFCI or AFCI breaker would appreciate it though.

here is an article that suggests insulation resistance tests should be part of regular maintence of MCCBs.

https://www.ecmweb.com/content/assuring-dependability-field-testing-mccbs

Generally, the maintenance procedures and tests regularly done on MCCBs include visual inspection; lubrication; cleaning; insulation resistance tests; contact resistance tests; and overcurrent tests.