As I was working on a lighting circuit I caused a shot circuit which caused a main to blow.I then proceeded to fix the short and turn the main back on causing the lcp to blow up! which then blow the main 400amp breaker that fed the 480 volt switchgear which was a ghi breaker.That breaker fed the first and seconed floor.My boss then proceeded to turn the ghi breaker back on which did not blow the lcp on the seconed floor.Why did the lcp blow up with that surge of power on the first floor and not the seconed floor lcp?Is one of the panels wired different?
Lcp Blowup
- Thread starter BRO-WIRED
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brian john
Senior Member
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- Leesburg, VA
As I was working on a lighting circuit I caused a shot circuit which caused a main to blow. I then proceeded to fix the short and turn the main back on
Basically when I get from your post is this system has a lack of coordination.
LCP=?
GHI=?
400 amp feeds the switchgear?
From what I think you are asking.
Most likely the problem was the service has Ground fault Protection (GFP), this GFP relay has current and time delay settings, if the current settings and time delay are set below the operating current and delay of the branch circuit breaker the Main will trip.
Basically when I get from your post is this system has a lack of coordination.
LCP=?
GHI=?
400 amp feeds the switchgear?
From what I think you are asking.
Most likely the problem was the service has Ground fault Protection (GFP), this GFP relay has current and time delay settings, if the current settings and time delay are set below the operating current and delay of the branch circuit breaker the Main will trip.
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