NEC Art.'s 230.7 & 312.8 ???

Rick W.

Member
Location
Lancaster SC
Occupation
Building Inspector
I have a contractor that is wanting to use Art. 230.7 & 312.8 to leave meter base with unfused service entrance conductors and feed through a sub-panel to get to the new ATS. My question is on protected (fused) and unprotected wire and feeding through the sub-panel. Do either one of these articles allow this.
 

jap

Senior Member
Service conductors, feeders and branch circuits can occupy service "enclosures", however, they cannot occupy a common "raceway".
 

Rick W.

Member
Location
Lancaster SC
Occupation
Building Inspector
Thanks, I agree, the commentary for 230.7 in NEC Handbook says the gutter space in these enclosures are not a raceway, but it says the conductors terminate or originate on OCPD's in the enclosure in order to share the gutter space.
 

jap

Senior Member
The gutter space in an enclosure is part of the enclosure.

Conductors that "terminate" on the line side of an OCPD from the utility in a service enclosure are Service Conductors.
Conductors that "originate" on the load side of an OCPD in that enclosure are Feeder or Branch Circuits.

There's really no way around the 2 sharing the "gutter space" in Service Equipment.

You could have service conductors from a meter pass through one panel enclosure's gutter space to feed one next to it as long as those service conductors don't share a common raceway with feeders or branch circuits from either panel.

JAP>
 

Rick W.

Member
Location
Lancaster SC
Occupation
Building Inspector
312.8 (A) (3) for feed-through requires a label that identifies the closest disconnecting means. When the feed-through conductors are service entrance conductors from the meter base they have NO disconnecting. How can you meet this requirement???
 

jap

Senior Member
The rule indicates a label that identifies the closest disconnecting means.

It doesn't indicate who's or where that disconnect may be located.

In my mind, that includes a power company's disconnecting means ahead of the meter if that should be the case.


Others may see it differently.

JAP>
 

Rick W.

Member
Location
Lancaster SC
Occupation
Building Inspector
I was not aware that the NEC recognized the Electric Utilities equipment as part by this code. I'm sorry but I do not understand the intent of this code article. How does allowing unfused wire without a disconnect feed through a sub-panel improve the safety of any electrical installation?
 

jap

Senior Member
I was not aware that the NEC recognized the Electric Utilities equipment as part by this code. I'm sorry but I do not understand the intent of this code article. How does allowing unfused wire without a disconnect feed through a sub-panel improve the safety of any electrical installation?

It doesn't improve safety.

It's inevitable.

For example: Every back to back or side by side installation of an outdoor meter into a Main Breaker Service Panel is the same scenario.

You have unfused Service Conductors without a disconnect in the same enclosure.
 

Rick W.

Member
Location
Lancaster SC
Occupation
Building Inspector
Yes I agree Art. 230.7 makes that clear, but in a back to back installation the SEC and branch circuits terminate on OCPD in the service panel as mentioned in the commentary. The installation I am looking at the SEC from meter base feed-through what is now a sub-panel to another remote enclosure. This is not safe and I can't find anywhere in the NEC that allows this.
 

jap

Senior Member
Yes I agree Art. 230.7 makes that clear, but in a back to back installation the SEC and branch circuits terminate on OCPD in the service panel as mentioned in the commentary. The installation I am looking at the SEC from meter base feed-through what is now a sub-panel to another remote enclosure. This is not safe and I can't find anywhere in the NEC that allows this.

Although the Service Conductors may terminate on a OCPD in the Service Panel in a back to back install, they still are unfused and have no disconnecting means ahead of the termination point in the Service Panel.

JAP>
 

jap

Senior Member
If those service conductors go from the meter through a Service Panel to a Service rated Transfer Switch without actually being in a raceway with feeder or branch circuits, there may not be an issue to be found.

There may be an issue that I'm not aware of, but, if there was, you'd have to find something in the code that "didn't " allow it, not one that would.

Jap>
 

Rick W.

Member
Location
Lancaster SC
Occupation
Building Inspector
To me this looks like convenience taking priority over safety. My interpretation 230.7 using the 2nd paragraph of the commentary to help understand the intent is that SEC and branch circuits can be in the same if they terminate on OCPD in that panel. Unless there is another code Art. that will allow this.
 

mikeames

Senior Member
Location
Germantown MD
Occupation
Teacher - Master Electrician - 2017 NEC
I see your point but I agree with JAP. The closest disconnecting means would be the ATS, but of course that would not de-energize the service conductors. The code requires service disconnects but never speaks to de-energizing service conductors. I think this is one of those issues that that was not thought about so 230.7 is not clear. 230.7 is simply requiring a label, it is NOT requiring the disconnect for the conductors to pass through. So a label stating that there are energized services conductors with NO disconnect meets the requirement in my opinion.
 

mikeames

Senior Member
Location
Germantown MD
Occupation
Teacher - Master Electrician - 2017 NEC
To me this looks like convenience taking priority over safety. My interpretation 230.7 using the 2nd paragraph of the commentary to help understand the intent is that SEC and branch circuits can be in the same if they terminate on OCPD in that panel. Unless there is another code Art. that will allow this.
I don't see the safety issue no more than any other service panel. Please explain the safety issue that exists that does not currently exist with normal service equipment.

Commentary is not code, nor is intent. Even 230.7 does not apply since we are not using a raceway.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
Rick I am not sure the nec directly addresses this issue however if the conductors were labeled as service conductors then I don't really see a major concern with this install.

As authority having jurisdiction you have the right to turn it down but IMO you should be able to show proof. I am not certain it is there...
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
It sounds like the service conductors may pass through another panel on the way to the new main, but cannot share the same nipple as the feeder conductors coming back.

Another option could be to route the service conductors below and around the existing panel with a pair of elbows or a pair of LBs.
 

mikeames

Senior Member
Location
Germantown MD
Occupation
Teacher - Master Electrician - 2017 NEC
It sounds like the service conductors may pass through another panel on the way to the new main, but cannot share the same nipple as the feeder conductors coming back.

Another option could be to route the service conductors below and around the existing panel with a pair of elbows or a pair of LBs.
Or two nipples.
 

jap

Senior Member
I picture a meter with a service panel next to it.
The customer now wants a generator.
The contractor wants to disconnect the service conductors from the existing main, run new service conductors from the meter through the panel to the utility side of the transfer switch then back from the ATS to refeed the panel.

As already mentioned, as long as the service conductors don't share the same raceway with any other feeder or branch wiring going there or coming back,I don't see the issue with it.



Jap>
 
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