Service Entrance questions and terminology

[Dave Hahn]

OK, I'm seeing this panel type with more frequency and am not sure I'm representing things properly or using the correct terminology.

Usually a meter box is naturally locked (w/utility lock) and on this panel type I typically can't see what I see here, but instead would only see what's accessible from the service equipment side.

So what I usually get to see are four #1 AWG copper conductors connected to a 200-Amp "quad-pole" (terminology?) main service disconnect. But with access to the meter box here, I now see that there's 4/0 AWG aluminum conductors attached to the meter AND THEN the four #1's from the meter to the disconnect (see photos).

Assumptions:
(i) #1 CU has a 150-amp capacity. 4/0 AL has a 200-amp capacity.
(ii) I'm required by SOP to report service amperage and service entry conductor type.

QUESTION(S):
Without being able to see what I see in this case, I'd say that the service "capacity" (not required to report) was 300-amps (?) because of the double #1 CU, but that the service amperage was 200-amp due to the disconnect, and the SEC type was CU.

But in fact, isn't the "capacity" 200-amp due to the 4/0 AL, the service amperage still is 200-amp due to the disconnect, and the SEC type is AL ??

If the SEC is the 4/0 AL, which I normally wouldn't see in a lateral, what do I call the four #1 CU ??

Dave

[Jerry Peck]

OK, I'm seeing this panel type with more frequency and am not sure I'm representing things properly or using the correct terminology.

That is a 'combination meter/service equipment' enclosure, with both in the same enclosure.


Assumptions:
(i) #1 CU has a 150-amp capacity.

4/0 AL has a 200-amp capacity.

Not quite right there. You are applying the ratings given in the notes to the ampacity tables, which do not apply to the service lateral side of the service (the conductors coming up from the bottom at the meter side in your photo). Those ratings only apply to the service entrance conductors in (for dwelling units only, not even commercial, for non-dwelling unit ratings you would need to refer to 310.15 Ampacity Tables.


(ii) I'm required by SOP to report service amperage and service entry conductor type.

QUESTION(S):
Without being able to see what I see in this case, I'd say that the service "capacity" (not required to report) was 300-amps (?) because of the double #1 CU, but that the service amperage was 200-amp due to the disconnect, and the SEC type was CU.

No, the service ampacity (amperage) and "capacity" are one and the same. That being the lowest of all the ratings, in this case, the 200 amp main disconnect.


But in fact, isn't the "capacity" 200-amp due to the 4/0 AL, the service amperage still is 200-amp due to the disconnect, and the SEC type is AL ??

You've lost me there, I'm not understanding what you are asking.


If the SEC is the 4/0 AL, which I normally wouldn't see in a lateral,

Those are not the service entrance conductors (SEC), those are the service laterals.

[quote] what do I call the four #1 CU ??[/quote

Those are the service entrance conductors (SEC).

I hope that helped.

[brian schmitt]

dave,
the 4/0 al conductors for underground service usually are provided and installed by the poco. it is on their side of the meter. do not concern yourself with these as they are secured by the poco to prevent power theft. the 4 #1 copper wires and the main disco are a factory installed assembly and not your concern either. check stuff after the 200 amp disco if you want to do something!

[Jerry Peck]

the 4 #1 copper wires and the main disco are a factory installed assembly

Which is why I did not say anything about the too sharp bends ... if the electrical contractor made those bends, the bends would be too sharp, but being as those bends are part of a UL listed assembly, those sharp bends are okay.

Nonetheless, though, the service laterals coming up into the box should be sealed around at the conduit, which looks like it should have a bushing.

Also, see that rusty looking shot pin in the back of the meter side of the enclosure? That was shot through the flat back of the enclosure and should have been shot through the standoff feet, seen to the right of it. The standoff feet are there to provide the REQUIRED 1/4" air space between the back of the enclosure and the wall, and when shot through the back like that one was, the back if now *pulled tight* to the wall - no 1/4" air space.