215.10 Ground Fault Breakers

[I-learns]

215.10 requires each feeder disconnect rated 1000 amps or more on services exceeding 150V to ground to have ground fault protection. My experience only includes services up to 1600A. In these cases, a ground fault breaker would only be installed on the main breaker, as any sub panels would not normally exceed 1000a. I have never been in a building that has, maybe some 1000a sub switchgear ran from a main service to a different area of the building.

In a case where there were sub pieces of switchgear of 1000a or more, would one normally have a ground fault breaker in those locations as well?

 

[infinity]

For the sub switchgear that you've mentioned, if over 999 amps it would already have the GFPE protection on it's supply end so no further protection would be required.

 

[Dennis Alwon]

Trevor would the setting on the gfpe breaker have to be done by an engineer?

 

[infinity]

Trevor would the setting on the gfpe breaker have to be done by an engineer?

I'm not sure that it's required by the NEC but we do not set them that's left up to the design engineer or the buildings MEP consulting firm. When I install switchgear containing GFPE relays I set all of the settings to 100% if they're not already set to 100% by the manufacturer (the last switchboards that we installed all came set to 100%).

A few years ago we had installed a two 4000 amp services in a new building and the GFPE relays were set to the minimum percentages from the factory. Myself and two other electricians climbed into an elevator that went about three floors, stopped and then went black. The GFPE had tripped the service disconnect feeding the elevator so we sat in there for 15 minutes waiting for someone to reset it. Luckily one of us had a radio and we were able to call the foreman because cell phones didn't work in the elevators.

 

[Dennis Alwon]

My luck is that I would be stuck there with 2 workers with BO and bad breath. Fortunate you didn't have to be there too long.

 

[infinity]

My luck is that I would be stuck there with 2 workers with BO and bad breath. Fortunate you didn't have to be there too long.

LOL.

 

[iwire]

215.10 requires each feeder disconnect rated 1000 amps or more on services exceeding 150V to ground to have ground fault protection. My experience only includes services up to 1600A. In these cases, a ground fault breaker would only be installed on the main breaker, as any sub panels would not normally exceed 1000a. I have never been in a building that has, maybe some 1000a sub switchgear ran from a main service to a different area of the building.

In a case where there were sub pieces of switchgear of 1000a or more, would one normally have a ground fault breaker in those locations as well?

Regardless of code required or not you will find them specified by engineers often. I suspect it has to do with overall coordination.

 

[don_resqcapt19]

For the sub switchgear that you've mentioned, if over 999 amps it would already have the GFPE protection on it's supply end so no further protection would be required.

While not required, you cannot have a selectively coordinated system without downstream GFPE protection. Most of the industrial switch gear I have worked on has GFPE on the main and the downstream feeder breakers.

 

[infinity]

While not required, you cannot have a selectively coordinated system without downstream GFPE protection. Most of the industrial switch gear I have worked on has GFPE on the main and the downstream feeder breakers.

For whatever reason (cost I would guess) the stuff that we've installed lately has had the code required minimum which is usually at the service disconnects. Remote switchboards even over 999 amps get no protection beyond the GFPE at the source of the feeder.

 

[I-learns]

For the sub switchgear that you've mentioned, if over 999 amps it would already have the GFPE protection on it's supply end so no further protection would be required.

I have definitely seen breakers in excess of 1000A without GFPE, and someone could also install a fused disconnect with no GFPE. Does anyone know, then, if 225.10 would require a ground fault breaker on a breaker at 1000A or more, if that breaker is already protected by a service disconnecting means with ground fault protection?

 

[augie47]

I have definitely seen breakers in excess of 1000A without GFPE, and someone could also install a fused disconnect with no GFPE. Does anyone know, then, if 225.10 would require a ground fault breaker on a breaker at 1000A or more, if that breaker is already protected by a service disconnecting means with ground fault protection?

The use of a fused disconnect does not relieve the requirement for GF protection.
I believe this thread is addressing the "downstream" protection and a GF protected service would allow downstream protection 100 amps or over to be installed without GF protection as that protection would already be in place.