ECN Forum Forums General Topics of the Trade General Discussion Area Very strange single line diagram?

I've never seen a service set up like this one that came in for us to bid.
Is this common in some other part of the country?
Here in Southern CA, it certainly isn't how it's done.








Have any of you seen something like this??...S

Unless I am missing something, I don't see anything unusual. Only thing I would do different is runn paralell 250's instead of 600's

[This message has been edited by ayrton (edited 03-19-2004).]

They use that in our area . The 1 1/4 is for utility company metering wires. They put the ct's at the transfomer,you then run straight to the main service panel with your service conductors from the transformor. This is only used on larger services.

Hello Electure, I agree with the others, this a common installation (design) here also.

Roger

Where do you guys get that 4-1/2" conduit? Do your supply houses stock it or is it special order?

Hmmmm, I didn't pay attention to that.

Come to think of it, with a conflict between the notes and reality, it's actualy a more common design than I first thought.

Roger

[This message has been edited by Roger (edited 03-19-2004).]

Is your question about the metering set up? I see this on "canned" drawings where the E.E. is from a different state and the job is for a nation wide chain type store. So then the question becomes - How do I bid this and stay competitive? Include the C.T. can, C.T.'s labor etc. or not? I have bid this type of set up per drawings with an adder to meet local requirements.

Most often the POCO will furnish the 13 terminal Meterbase for the CT installation, you would just have to mount it on some 2" Rigid & Strut. As for the conduit, I would also parallel conductors & use a smaller, more common size of conduit. Watch the price of the copper though, it has been going up lately, & could change quickly.

The POCO will dictate where the metering enclosure is to be mounted. If you have never seen it like that before (me neither) then you need to check with the POCO as to where they accept the CT meter. Out here (New England) we have to purchase and install a separate CT/PT enclosure, usually as part of the main disconnect, then the meter can is remotely mounted outside the building.

4-1/2 inch conduit? I've never run across it before. Maybe it is metric, then rounded off?

The 4 1/2" conduit seems a little strange.

As earlydean has said in our area the metering CTs would be inside, I tried to get the local POCO go with this setup before due to space limitations in the building, they said they do not want metering at the transformer in case a replacement is needed they won't have to get the metering guys involved with the swap out.

ayrton and Megawatt, this appears to me to be a 1,200 amp service, 3 sets of 600s, assuming copper.

Are you saying you would rather run 5 sets of 250s in place of 3 sets of 600s?

Why?, more time more material.

I would not try or want to use smaller cable 600 kcmil is great in 3 1/2" conduit.

My wild guess is that Note 4 should read.

"4) PROVIDE 3 SETS 4 #600KCMIL-3 1/2" C"

Bob