malachi constant
Senior Member
- Location
- Minneapolis
I have always understood panels (breaker panel, distribution panel, switchboards, etc) that are rated "service entrance" to have two things different: a main bonding jumper and a UL sticker. However I have a situation that has me scratching my head.
I am the engineer and designed a service to a new building with a service-entrance rated distribution panel (with a main breaker) located inside the building. The contractor called up to say we need to add a disconnect outside...because otherwise they can't safely shut off power to the building without calling the utility company. But isn't that what the main disconnect is for, I ask? Yes, they say, but if we shut it off we still have to put on a moon suit to work on the panel since it has live feeders coming into it.
In review of the shops (screensnip attached, with identifying information removed) I see there is no listing anywhere of the equipment as service entrance rated. I see that the main breaker (1000A I believe) is nestled up in with the other distribution breakers - it appears to receive power into the breaker, and the breaker then feeds the bussing. I don't have a very responsive contact with this manufacturer so ran it past another manufacturer. My question being, weirdness aside of how the panel fed, do I need to start designing services with the disconnect in its own enclosure/section? This manufacturer stated that service entrance equipment has a barrier that physically separates the lugs from the rest of the panel, making it safe to work in "cold" once the switch has been turned off and bus has been confirmed as cold.
Where to begin in sorting this out...
1) Does service entrance rated mean that main lugs should include a physical barrier?
2) Service entrance rating aside - are service panels generally constructed with that kind of a physical barrier?
3) Does such a physical barrier allow for service panels to be worked on as if they were cold, even with hot utility conductors terminated within?
4) If not...how does one design something like this, with safety in mind? How does this work IRL? When an electrician needs to add a new breaker in a service panel, are they usually calling the utility company? Usually working as if it was hot, wearing proper PPE (though many panels will not have level of PPE listed)? Does one usually find a physical barrier separating the utility conductors, that allows you to work as if it was cold?
Then - almost an aside but actually the hot item right now - the electrician is adamant we need a disconnect outside. The panel does not appear to have a service entrance rating but does have a main breaker. Does the proposed exterior disconnect need to be service rated? Does it need to be fused, or is this now acting only as a safety switch so it can be non-fused? If the disconnect is not fused or service rated, the can the electrician bond the neutral and ground within the "service" panel that is already ordered?
I need to engage the manufacturer and the electrician to get on the same page here, but am hoping the community here can clarify my thinking a bit first. Thanks!
I am the engineer and designed a service to a new building with a service-entrance rated distribution panel (with a main breaker) located inside the building. The contractor called up to say we need to add a disconnect outside...because otherwise they can't safely shut off power to the building without calling the utility company. But isn't that what the main disconnect is for, I ask? Yes, they say, but if we shut it off we still have to put on a moon suit to work on the panel since it has live feeders coming into it.
In review of the shops (screensnip attached, with identifying information removed) I see there is no listing anywhere of the equipment as service entrance rated. I see that the main breaker (1000A I believe) is nestled up in with the other distribution breakers - it appears to receive power into the breaker, and the breaker then feeds the bussing. I don't have a very responsive contact with this manufacturer so ran it past another manufacturer. My question being, weirdness aside of how the panel fed, do I need to start designing services with the disconnect in its own enclosure/section? This manufacturer stated that service entrance equipment has a barrier that physically separates the lugs from the rest of the panel, making it safe to work in "cold" once the switch has been turned off and bus has been confirmed as cold.
Where to begin in sorting this out...
1) Does service entrance rated mean that main lugs should include a physical barrier?
2) Service entrance rating aside - are service panels generally constructed with that kind of a physical barrier?
3) Does such a physical barrier allow for service panels to be worked on as if they were cold, even with hot utility conductors terminated within?
4) If not...how does one design something like this, with safety in mind? How does this work IRL? When an electrician needs to add a new breaker in a service panel, are they usually calling the utility company? Usually working as if it was hot, wearing proper PPE (though many panels will not have level of PPE listed)? Does one usually find a physical barrier separating the utility conductors, that allows you to work as if it was cold?
Then - almost an aside but actually the hot item right now - the electrician is adamant we need a disconnect outside. The panel does not appear to have a service entrance rating but does have a main breaker. Does the proposed exterior disconnect need to be service rated? Does it need to be fused, or is this now acting only as a safety switch so it can be non-fused? If the disconnect is not fused or service rated, the can the electrician bond the neutral and ground within the "service" panel that is already ordered?
I need to engage the manufacturer and the electrician to get on the same page here, but am hoping the community here can clarify my thinking a bit first. Thanks!
