Utility wiring 200A Service

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Twoskinsoneman

Twoskinsoneman

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Location
West Virginia, USA NEC: 2020
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Facility Senior Electrician
I'm wiring up a RV service for a buddy. I've been an onsite company electrician in an industrial facility for several years now and not really current as to normal procedure for this situation. So I was wondering about something.
He gave me the paper work from the utility for what he needs and it states that the utility is going to run 4awg 200ft to the meter for a 200A service. I know utilities don't use the NEC but this seems wrong. 4awg for a 200A service seems way to small. Is it normal for a RV or mobile home service?
I'm bringing 2/0 w/a 4awg grounded conductor from the meter to the service disconnect and a 4awg GEC to the rods.
Thanks.
 
I did a service a few weeks ago with 8 sets of 500mcm and the utility fed me with a set of 4/0

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Here's a couple of pics
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Twoskinsoneman said:
I'm wiring up a RV service for a buddy. I've been an onsite company electrician in an industrial facility for several years now and not really current as to normal procedure for this situation. So I was wondering about something.
He gave me the paper work from the utility for what he needs and it states that the utility is going to run 4awg 200ft to the meter for a 200A service. I know utilities don't use the NEC but this seems wrong. 4awg for a 200A service seems way to small. Is it normal for a RV or mobile home service?
I'm bringing 2/0 w/a 4awg grounded conductor from the meter to the service disconnect and a 4awg GEC to the rods.
Thanks.
Click to expand...

You are right the POCO can run any size wire they want. They also have actual usage data to help make the choice.

Since it's not a dwelling unit I would think you would need 3/0 Cu to be NEC compliant, not that it will make a difference in the real world.
 
POCO can use the smaller wire but the voltage drop under load, particularly motor starting, may be annoying. As long as it stays within the allowed power delivery range you will have no recourse except an appeal to customer good will.

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You can upgrade your panel here from 100 to 200 A and if it's an overhead, they won't change out the service conductors, just hook back up the old ones.
 
Twoskinsoneman said:
I'm wiring up a RV service for a buddy. I've been an onsite company electrician in an industrial facility for several years now and not really current as to normal procedure for this situation. So I was wondering about something.
He gave me the paper work from the utility for what he needs and it states that the utility is going to run 4awg 200ft to the meter for a 200A service. I know utilities don't use the NEC but this seems wrong. 4awg for a 200A service seems way to small. Is it normal for a RV or mobile home service?
I'm bringing 2/0 w/a 4awg grounded conductor from the meter to the service disconnect and a 4awg GEC to the rods.
Thanks.
Click to expand...

This being an RV I highly doubt you will get anywhere near 200A. Probably never see 100A. But IF you do, your #4 for the neutral is too small. Also, #6 is all that is required for a GEC for a rod.
 
Twoskinsoneman said:
...
I'm bringing 2/0 w/a 4awg grounded conductor from the meter to the service disconnect and a 4awg GEC to the rods.
Thanks.
Click to expand...
Did they make any stipulations on the meter can rating or service wiring ampacity? Do they have an online service installation guide?

Around here if we request a 100A service, and they run what they call a 200A service, the consumer side equipment only has to be 100A rated. Other POCO's may not permit this.
 
If PoCo only needs to feed 100A to similar customers, ignoring inside wiring 200A equipment, and can de-rate capacity similar to 310.15(B)(7) for dwellings, than 83Amps on #4cu is within the 60°C column of Table 310.15(B)(17) (formerly Table 310.17) single conductors in free air.
 
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Twoskinsoneman said:
I'm wiring up a RV service for a buddy. I've been an onsite company electrician in an industrial facility for several years now and not really current as to normal procedure for this situation. So I was wondering about something.
He gave me the paper work from the utility for what he needs and it states that the utility is going to run 4awg 200ft to the meter for a 200A service. I know utilities don't use the NEC but this seems wrong. 4awg for a 200A service seems way to small. Is it normal for a RV or mobile home service?
I'm bringing 2/0 w/a 4awg grounded conductor from the meter to the service disconnect and a 4awg GEC to the rods.
Thanks.
Click to expand...
What is the load - if just a single RV - the only concern with 4 AWG might be voltage drop, otherwise it is large enough to handle the load. 200 amp service is overkill, but at same time maybe you are figuring additional possible load down the road sometime.

2/0 could be used if this were a dwelling but the section that allows that doesn't apply to non dwellings so 200 amp conductor must be 3/0 copper, 6 AWG is all that is necessary to ground rods.
 
Heh Heh Heh. My 18" of 2/0 is too small but they can run 200ft of 4awg... Amusing. Thanks for everyone's comments.
They did spec out a 200a meter. And though it is for an RV and 50a recept for it is the only known load, the utility instructions call it a Underground Mobile Home Service so I figured 550.33(B) would let me run the 2/0.
But you guys are right. Plus I really don't want to go back out and fix anything that fails inspection so I will just run the 3/0.
 
Twoskinsoneman said:
..They did spec out a 200a meter. ..
Click to expand...

Did you up-sell a 200A service to supply a 50A-receptacle feeder, because your load calcs are based on Meter size rather than 550.31?

200A meters may be the least expensive to procure, or just associated with double-wide mobile homes by accident.
 
There is one POCO around here that only pulls 4/0 aluminum for underground for all services 200 amp or under, so if I were installing what OP has I would have to use a 200 amp meter base or else it would be challenge to land that 4/0 on a 125 amp meter socket. I probably would have installed a 200 amp meter/loadcenter combo if doing what OP is doing, but if for some reason was installing meter socket and separate service disconnecting means, I very well might have gone with 100 amp equipment on load side of meter.

Same POCO would run #4 aluminum triplex for this same service if the supply was overhead though:blink:
 
Regarding POCO wire size, it's up to the engineer and the expected (declared) load. As far as meter size, utilities only buy 200A 240/120V residential meters because they will meter accurately even if the customer requests a 100A service. In fact, our utility has one fee for "Up to 200A" to avoid the issue. Hard to find a utility that still allows 125A meter panels, because one type of meter reduces inventory needs and large number orders are usually cheaper. I'm not sure 100A meters are even still available.
 
meternerd said:
Regarding POCO wire size, it's up to the engineer and the expected (declared) load. As far as meter size, utilities only buy 200A 240/120V residential meters because they will meter accurately even if the customer requests a 100A service. In fact, our utility has one fee for "Up to 200A" to avoid the issue. Hard to find a utility that still allows 125A meter panels, because one type of meter reduces inventory needs and large number orders are usually cheaper. I'm not sure 100A meters are even still available.
Click to expand...
Yes most only use 200 amp class for self contained metering - they still fit a 125 amp or a 320 amp socket though.
 
kwired said:
..I probably would have installed a 200 amp meter/loadcenter combo if doing what OP is doing, but if ..separate service disconnecting means, ..100 amp equipment on load side of meter.
Click to expand...

If 200A equipment is using a 100A disconnect (OCP) with 310.15(B)(7) applied per 550.33(B), and with 75°C terminations, #4cu is adequate, rather than the 3/0 copper you mentioned earlier.
 
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ramsy said:
If 200A equipment is using a 100A disconnect (OCP) with 310.15(B)(7) applied per 550.33(B), and with 75°C terminations, #4cu is adequate, rather than the 3/0 copper you mentioned earlier.
Click to expand...

I'd think we'd actually need to look into 551 and 310.15(b)7 is actually for dwelling units which in my book an RV is not.

JAP>
 
ramsy said:
If 200A equipment is using a 100A disconnect (OCP) with 310.15(B)(7) applied per 550.33(B), and with 75°C terminations, #4cu is adequate, rather than the 3/0 copper you mentioned earlier.
Click to expand...

jap said:
I'd think we'd actually need to look into 551 and 310.15(b)7 is actually for dwelling units which in my book an RV is not.

JAP>
Click to expand...
I agree, needs to be 3 AWG or larger if not supplying a dwelling unit and is supplying a single 100 amp service disconnecting means.

RV is not a dwelling unit.

If the service supplies only a single outlet intended for an RV I would think the service disconnecting means must have a minimum of 30 or 60 amp rating depending on what the RV has for supply equipment.
 
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