Breaker Inspections

[emjpete]

Would you consider the timing of a breaker to be a critical part of a breaker inspection to be in compliance with osha 1910.269 App E?
If you can't prove the opening time of a breaker how can you be in compliance with 1910.269?

 

[pwrengrds]

That depends a lot on the breaker and what is meant by timing testing.

I have never seen timing tests on low voltage (<1000volts) breakers. Its commonly done on high voltage breakers (>100kV) on commissioning and during periodic maintenance. What the standard seems to be talking about is arc flash and the time to quench the arc.

It's relative common to do breaker testing on breakers >400 amps, at the 480/600 volt level which would include primary current injection with timing of the time to trip both inst. and at 3x over current and do that on a 5-10 year schedule.

Usually arc flash reports will have a statement that the results depend on the break being in operating condition with regular maintenance, which could be just operating it and cleaning or primary/secondary current injection.

David