600amp 3 Phase Service

[Benton]

I have a customer that has a 600 amp 3 phase service that he had installed, it is not complete yet. He is all ready feeding 2-200amp panel and 2-150amp panels from the main panel. But he still needs a few more 150amp panels to be feed (actually they are disconnects that are feeding panel but I plan to feed them straight from a main panel).

My question is. With the current scheme could I double lug (with appropriate lugging) from the main cabinet outside, go through CT's and feed a 400amp panel on inside? I am trying to give him more load space without replacing main 600amp panel. Any help is much appreciated.

How far do you have to stub up utility pole for PC?

Thanks

 

[augie47]

For me, there are way too many unknowns to give you an answer.
My first step would be to talk with the POCO.

(on second thought, the first step may be to ask the inspector if he needs to sit down as he looks faint )

 

[Dennis Alwon]

If you are trying to add 400 amps to this 600 amp service then I think you can go back to the CT and have the power company splice in there. But I agree with Gus - talk to the power company

 

[n1ist]

Not sure if it is intentional, but the two panels on the right look like they have different phasing...
/mike

 

[petersonra]

I have a customer that has a 600 amp 3 phase service that he had installed, it is not complete yet. He is all ready feeding 2-200amp panel and 2-150amp panels from the main panel. But he still needs a few more 150amp panels to be feed (actually they are disconnects that are feeding panel but I plan to feed them straight from a main panel).

My question is. With the current scheme could I double lug (with appropriate lugging) from the main cabinet outside, go through CT's and feed a 400amp panel on inside? I am trying to give him more load space without replacing main 600amp panel. Any help is much appreciated.

Do you need more current than the existing 600A service can supply? If it is just more CBs you need there would seem to be simpler answers.

 

[Fulthrotl]

Not sure if it is intentional, but the two panels on the right look like they have different phasing...
/mike

i'm wondering about derating branch circuits....
we used to put a 2" up to a 18 x 18 x6 box above the panel,
and just pull everything unbroken thru the 2" as
it's only about 3 or 4 feet long, but now, around
here anyway, it seems that more than 3 conductors
in a conduit kills that idea, even if it's only 3' long.
i always liked it, cause it was a clean install.

and can someone please straighten up those
pipes out the top of the panel?

 

[augie47]

i'm wondering about derating branch circuits....
we used to put a 2" up to a 18 x 18 x6 box above the panel,
and just pull everything unbroken thru the 2" as
it's only about 3 or 4 feet long, but now, around
here anyway, it seems that more than 3 conductors
in a conduit kills that idea, even if it's only 3' long.
i always liked it, cause it was a clean install.

and can someone please straighten up those
pipes out the top of the panel?[/QUOTE]

They were going to straighten them but they are too hot to touch

 

[kwired]

Do you need more current than the existing 600A service can supply? If it is just more CBs you need there would seem to be simpler answers.

I am with you, it would seem this is the first question to ask. Do we just need more circuit breaker spaces or are we adding enough load that 600 amps is not enough?

If adding more service disconnecting means you may want to look at what future needs may be and build for them now if it is likely there will be even more load. Once you get to six service disconnects, you become limited and have to redo existing things if more load is needed. Or at least design so that future changes are maybe easier to accommodate.

 

[n1ist]

The colors per pipe look OK since they are all single-phase circuits; I was talking about the phase tape on the feeders; one is blue brown orange, while the other panel has blue orange brown
/mike

 

[augie47]

The colors per pipe look OK since they are all single-phase circuits; I was talking about the phase tape on the feeders; one is blue brown orange, while the other panel has blue orange brown
/mike

From all other indications such as the number of SP breakers and the lack of branch ID, I don't think the orange is indication of a "high-leg" (I hope not)... so the difference in the two panels should not make a difference. Good eye though.
THe 1st thing that jumped out for me was Fulthrotl's thought about derating.
[h=1][/h]

 

[mwm1752]

What is the load calc for the structure with including upgrades? How many disconnects for the service? Rearrange the sub panels -- Maybe use feed thru panels before the existing sub panels to increase breaker spaces. Really not enough info

 

[GoldDigger]

From all other indications such as the number of SP breakers and the lack of branch ID, I don't think the orange is indication of a "high-leg" (I hope not)... so the difference in the two panels should not make a difference. ]

Since blue-orange-brown and blue-brown-orange are opposite phase rotation rather than just a cyclic shift, it will make a difference for three phase motors for sure. But if there are none, it will not matter much.