We're building a 400 amp service and met with the POCO engineer today and she said that they require CT's on any commercial service over 200. I mainly work in another POCO jusrisdiction, and they went to 400 amp meter bases at least ten years ago. I think they even have 600's.
I was told that it was much more accurate than CT's, but she held fast onto her CT's as best. Any opinions?

Gunther:
Here in NJ (Northern) a RESI 400 amp can be thru a meter pan. (320 continuous, single phase) or a CT can be installed. PSE&G territory. 3 phase is 200 amp meter pan, larger is CT.

Occasionally, a CT cab is omitted, and donut CT's placed on a rack at the weatherhead. Note 'occasionally'!

IMHO, the POCO is the 'boss', so you don't have much choice.

Here my POCO's have few diffrent verison of slipon/ bolton verison

Typically for resdetnail 400a and under useally have bolted on 400/600 amp meter socket but farm have to use C/T only { safety issue }

commercal it will varies a bit depending on the setup but useally all the C/T's will be found over 400 amp service it dont matter if you have 1Ø or 3Ø system in there.

Again the POCO will have final sayso on the setup.

Merci,Marc

We use the microlectric JS4A 400amp meter bases for our installations. These meter bases have built in CT's. Nice and easy.

Gunther, you are asking a question that appears to be geographically-based, but you don't have your location indicated in your profile or in your post. It's kind of hard for us to help you if we don't know where you are located since POCO policies vary greatly in different parts of the country.