Wire sizes for really short runs

[bdog]

I recently upgraded the main panel to 200 amp and feeder wires to 3/0 in my shop. The meter is right next to, about a foot away, from the transformer pedestal. While I had the meter can open hooking up the wires I noticed they were feeding the meter with #2.

I called the electric company about upgrading my service and they are they said my transformer and meter are good to 200 amps but the #2 needs to be changed to 1/0. How do they figure this - just because the wires are only a couple feet long? I have three pieces of 3/0 about 3’ long left over from the upgrade when the service guys get here I am going to try and get them to use those but I was just curious how they get by with 1/0 as standard for 200 amps.

 

[Bert_]

They don't size wires by the NEC. They also know it's nearly impossible for a residential service to pull anywhere near 200a for any length of time.

Chances are the transformer is a 15 or 25KVA which will do 60 or 100a continuous.

 

[alfredeneuman]

I recently upgraded the main panel to 200 amp and feeder wires to 3/0 in my shop. The meter is right next to, about a foot away, from the transformer pedestal. While I had the meter can open hooking up the wires I noticed they were feeding the meter with #2.

The PoCos are exempt from the NEC.
They've got their own engineers and figure the wire sizes differently, according to the expected connected load, and do a good job of that.

 

[bdog]

Interesting. Thanks for the information. My meter is for a shop that has pretty high demands. When the AC and everything else is running I am pretty sure I will be easily over 100 amps continuously. I have some unique things in there though that draw a lot.

 

[wyliesdiesels]

Are the PoCo engineers aware of the loads you will be running?

If not, then they would have no way of knowing what your actual lods would be.

 

[Bert_]

Continuous generally means 3 hours or more. If you manage to pull 200A for hours on end it might be an issue. Your electric bill would be in the thousands off that was the case.