Service conductors (or Service rated conductors?)

[electro7]

Wondering about running conductors from a meter main socket across the house in a crawl space to a service rated ats and then back to refeed the distribution in the meter main combo panel.

I am wondering what the NEC rules are on this and whether or not I am able to run those conductors the way I explained? There will be no OCPD upstream from them and therefore would always be hot with the grid.

I am leaning towards a self contained pass through main breaker near the meter as the service diaconnecting means in order to de-energize those conductors.

Would these conductors I explained above be considered "service conductors" or "service entrance conductors"? Its been a while since I have completed my apprentichsip and am a bit confused on the NEC definitions for all the "service" definitions and real world applications of each.

Thanks!

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[augie47]

Conductors without overcurrent protection can be routed on the interior of a structure for a very limited distance. Depending on your Code cycle the service disconnect must be outside or "nearest the point of entry of the conductors"

 

[electro7]

Okay, these are going approx. 40ft. What NEC code section would that be located in that allows it but limits distance?

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[augie47]

Okay, these are going approx. 40ft. What NEC code section would that be located in that allows it but limits distance?

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230.70

 

[electro7]

Not seeing distance requirements in that code section.



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[infinity]

Not seeing distance requirements in that code section.

There isn't one it simply says nearest. 40' is not going to be nearest.

 

[electro7]

Gotcha, understand. Thanks

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[infinity]

Gotcha, understand. Thanks

Some places allow up to 15' into the structure, around here the SEC's need to go directly into the service disconnect or panel. You may be able to enter the structure for only a few feet. It's up to the AHJ to decide what "nearest" means.

 

[tom baker]

The distance for un fused service in a building conductors vary greatly by jurdisction

 

[Fred B]

Some places allow up to 15' into the structure, around here the SEC's need to go directly into the service disconnect or panel. You may be able to enter the structure for only a few feet. It's up to the AHJ to decide what "nearest" means.

Had one municipality that only allowed 6 foot from point of entry to the main breaker. I got called into picture late and a GC did the initial installation and the Code Enforcement Officer required that it be shortened, It was 6.5ft. Had a bunch of short branch circuit wires as a result. I think the original GC had made the CEO mad at some point as he made the guys remove a bunch of sheetrock for visuals on insulation and plumbing too. That one got me my first install of a big on demand electric water heater three 40A double pole. It also had a bunch of messed up 3ways that had to get fixed.

 

[DrSparks]

Nearest the point of entrance. Usually means straight down into the panel after penetrating the joist header. It's truly an AHJ call. I say an unfused service entrance (especially SE cable should go straight into a panel. Or back to back through a nipple would be best.

If you use a main breaker outside near the meter, or better yet, a meter with a built-in main breaker, the wires coming in to feed the panel are no longer "service entrance wires," but rather a feeder. Your ground to neutral bond will occur in the main breaker or meter enclosure and you'll bring a suitably sized EGC in with the feeder wires. This can be accomplished using SER cable: 2-2-2-4 for 100amp, and 4/0 4/0 4/0 2/0 for 200 amp respectively.

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[curt swartz]

If I were inspecting this there is no way I would accept your proposed modification of the combination service entrance device even if the transfer switch was next to it. These are UL listed assemblies. There is no field provisions for intercepting the the service conductors (or buss bars) between the meter and main breaker. Even if there were an approved way to intercept the line conductors the neutral is factory bonded to the enclosure.

 

[DrSparks]

If I were inspecting this there is no way I would accept your proposed modification of the combination service entrance device even if the transfer switch was next to it. These are UL listed assemblies. There is no field provisions for intercepting the the service conductors (or buss bars) between the meter and main breaker. Even if there were an approved way to intercept the line conductors the neutral is factory bonded to the enclosure.

Maybe a service rated ATS, that's about it.

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[electro7]

If I were inspecting this there is no way I would accept your proposed modification of the combination service entrance device even if the transfer switch was next to it. These are UL listed assemblies. There is no field provisions for intercepting the the service conductors (or buss bars) between the meter and main breaker. Even if there were an approved way to intercept the line conductors the neutral is factory bonded to the enclosure.

This has been a quandary of mine since the desire for home stand-by generators has increased in our area, and we have a lot of meter main combo panels. Often times there isnt a good way to re-route all of the branch circuits and feeders because there is a bedroom or such behind the wall of the service panel and windows to each side of it. With that said, do you have any good solutions for backing up the whole house in this type of situation?

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[Fred B]

If I were inspecting this there is no way I would accept your proposed modification of the combination service entrance device even if the transfer switch was next to it. These are UL listed assemblies. There is no field provisions for intercepting the the service conductors (or buss bars) between the meter and main breaker. Even if there were an approved way to intercept the line conductors the neutral is factory bonded to the enclosure.

This has been a quandary of mine since the desire for home stand-by generators has increased in our area, and we have a lot of meter main combo panels. Often times there isnt a good way to re-route all of the branch circuits and feeders because there is a bedroom or such behind the wall of the service panel and windows to each side of it. With that said, do you have any good solutions for backing up the whole house in this type of situation?

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It seems to me you found the downside of the meter/main, especially if it is used as main panel not just as a disconnect. Sounds as if this panel in reference is the main panel type and all circuits (or most) are terminating their. If that is so a branch circuit style ATS would be required and transfer the loads into the ATS. This can be done off to the side of a window or door, as you simply extend the branch wires from existing location inside the meter/main to transfer switch and back.
My only question is the 6ft rule about extending a circuit wire, would it then require AFCIs on circuits that didn't originally have (but now required in the particular space) that wasn't required for an original upgrade, but if the extensions are more than 6ft to the ATS?
(I'll let someone else weigh in on that.)

 

[Fred B]

Carl makes a good point for factory connections of the meter/main that would be a no no to intercept or alter the UL listed combination connection. Thus my suggestion for a branch style ATS.

 

[Dennis Alwon]

Why not install the ats next to the meter. Also, is it possible to separate the meter from the panel with a meter main panel? The ones I see are wired thru buss bars.

 

[electro7]

 It seems to me you found the downside of the meter/main, especially if it is used as main panel not just as a disconnect. Sounds as if this panel in reference is the main panel type and all circuits (or most) are terminating their

Yes. It is a downside. I am from NY and this style panel was rare there where I was from. Now in CA thats all they have here. I would say 90% of the time all of the branch circuits and feeders are landed in this type of panel. And usually are jammed packed with wires trying to fit in all the circuits with limited room.

Some have wires from the meter to a 4 pole main breaker that stabs on to the busbar that is the distribution for all of the house loads. Others have bussing feeding the main breaker and from the load side of the main it is connected to the distribution buss either with wires or a bolted on buss bar. This style seems easier to intercept off the load side of the main and route the hots through the ats. Then come back to refeed the distribution buss.

But as pointed out the factory nuetral ground bond on these panels seem to be the biggest hang up. Most have the nuetral from the utility landing on a lug that has a bus bar that is bonded to the enclosure.

Really the only way I see making a good code compliant installation is to either re-route all of the branch circuits and feeders as suggested which can be a huge task. Or changing out the service panel that could have a sub panel separate from a meter base with a main breaker type set up. Im going to have to do my research on panel manufacturers that supply a good set up. Tricky part is some services are recessed in the wall and are underground or overhead, some are surface mount underground or overhead and some have the mast coming in the center or some in the side.


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[Fred B]

 It seems to me you found the downside of the meter/main, especially if it is used as main panel not just as a disconnect. Sounds as if this panel in reference is the main panel type and all circuits (or most) are terminating their

Yes. It is a downside. I am from NY and this style panel was rare there where I was from. Now in CA thats all they have here. I would say 90% of the time all of the branch circuits and feeders are landed in this type of panel. And usually are jammed packed with wires trying to fit in all the circuits with limited room.

Some have wires from the meter to a 4 pole main breaker that stabs on to the busbar that is the distribution for all of the house loads. Others have bussing feeding the main breaker and from the load side of the main it is connected to the distribution buss either with wires or a bolted on buss bar. This style seems easier to intercept off the load side of the main and route the hots through the ats. Then come back to refeed the distribution buss.

But as pointed out the factory nuetral ground bond on these panels seem to be the biggest hang up. Most have the nuetral from the utility landing on a lug that has a bus bar that is bonded to the enclosure.

Really the only way I see making a good code compliant installation is to either re-route all of the branch circuits and feeders as suggested which can be a huge task. Or changing out the service panel that could have a sub panel separate from a meter base with a main breaker type set up. Im going to have to do my research on panel manufacturers that supply a good set up. Tricky part is some services are recessed in the wall and are underground or overhead, some are surface mount underground or overhead and some have the mast coming in the center or some in the side.


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Your second option you mention of changing the service panel would be a much bigger job that using a branch circuit style ATS. Some smaller ones are pre wired. But even if not you don't actually reroute the branch circuits they stay in the meter/main and a jumper is run out for each to the ATS and back, no change for N/G bonding required either.

 

[electro7]

 Your second option you mention of changing the service panel would be a much bigger job that using a branch circuit style ATS. Some smaller ones are pre wired. But even if not you don't actually reroute the branch circuits they stay in the meter/main and a jumper is run out for each to the ATS and back, no change for N/G bonding required either.

Just to confirm all of the nuetrals and grounds need to originate from the same panel as the hots, correct? Whats the NEC section for that?

I can combine grounds and bring over a #8 or #6, correct? How do I size that according to NEC?

Thanks again

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