TIMING SWITCHGEAR BREAKERS

[bure961]

WHEN AN ARC FLASH STUDIES ARE DONE ARE THE SWITCHGEAR BREAKERS CHECKED FOR THEIR OPENING TIME OR IS ARE THE TIMES TAKEN FROM SOMETHING LIKE A OWNERS MANUAL ?

 

[zog]

WHEN AN ARC FLASH STUDIES ARE DONE ARE THE SWITCHGEAR BREAKERS CHECKED FOR THEIR OPENING TIME OR IS ARE THE TIMES TAKEN FROM SOMETHING LIKE A OWNERS MANUAL ?

Typically they are not checked, arc flash studies are usually done based off the TCC and assumed opening time. Even if you were to check timing in the tradational sense it does nto represent the real world opening time when the breaker sits closed in the cubical for months or years. Traditional timing requires the breaker to be opened, racked out, and tested. Once you open it you lost the true opening time.

To get the true opening time you would need to do "First trip" timing tests. We use this.
http://www.circuitbreakeranalyzer.com/breaker-first-trip-testing.htm