Wire sizing requirements for 200A service

[lensovet]

Someone please set me straight on this.

My understanding is that for regular residential service, you would need 3x 4/0 aluminum wire or 3/0 copper wire from the meter to the load center.

Is this right?

If so, when we took off the meter, the wire coming in from the utility was just #2 copper. Asked the guys from the POCO and they said no problem.

What is the point of running 4/0 wire from the meter if the wire coming into it is just #2? Please set me straight.

In case it matters, the service here is fully underground (no poles, aka BUD) and is supplied by PSE&G in south jersey.

 

[Open Neutral]

My guess:

a) They play by their own rules, not yours. Their side of the meter, they eat those I^2R losses.
b) If aerial, cooling is not the issue it is in conduit.

 

[farmantenna]

utility companies use different standards.

think about this: at a condo development the utility uses 75kva xformer for 5 buildings and each has 2 2k sq ft condos with a NEC calculated load of around 110 amps (I don't recall my exact figure). I saw their engineer one day and ask about it. He said it was very typical and xformer has short term overload capacity.

 

[tom baker]

POCO guys are correct, no problem, they have their own standards based on many years experience, the NEC load calculations are very conservative.
Around here line trucks only carry # 2 and 6 AL, but that is for conductors in free air.

 

[lensovet]

I see. Bummer that I’m stuck wrangling those giant wires into my panel.

Follow-up question, did I size the neutral correctly, or could it have been downrated to something smaller?

 

[ActionDave]

I am closing this thread, in accordance with the Forum’s rules.

This site is designed for:

Contractors
Electricians
Engineers
Inspectors
Instructors
Other electrically related individuals
This NEC Forum is for those in the electrical and related industries.

Forum rules prohibit us from assisting a person to perform or assist others to do electrical work who are not qualified. The reason is that the forum’s owner does not want a person to get an answer to the question they asked, but not get answers to the other questions they should have asked and were unaware they needed to ask. Mike Holt Enterprises and the Moderators of this Forum do not wish to place you and your family in danger, by allowing others to give you too little information to ensure that the installation is safe