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Simple question about voltage and current ratings #208706 02/07/13 06:10 PM
Joined: Feb 2013
Posts: 3
P
piphomer Offline OP
New Member
Dear all,

I am new to the industry and new to this forum. So thanks for bearing with me on a simple question!

When a 3-phase electrical box, eg this one is rated at 400A, does that mean 400A per phase, or 400A total i.e. 133A per phase?

Also, this box for example is rated as 600V - does that mean phase to phase, or each phase to neutral?

Many thanks!!

-Phillip

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Re: Simple question about voltage and current ratings [Re: piphomer] #208707 02/07/13 07:41 PM
Joined: Jul 2004
Posts: 9,394
G
gfretwell Offline
Member
That is 400a per phase. The 600v is phase to phase.
For a 600v wye, l/n would be 347 as would be the wild leg of a center tapped 600v delta although I have never heard of doing it.
Typically you see 480v as the high end of "low voltage". (a multiple definition term itself)


Greg Fretwell
Re: Simple question about voltage and current ratings [Re: piphomer] #208708 02/07/13 10:03 PM
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Posts: 3
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piphomer Offline OP
New Member
Thanks!

So does that mean that for a 230V phase-phase (400V phase-neutral) system with a max current per phase of 160A, I actually can use a DH324NRK instead of the one in the previous link? Or do I have to go to the DH364NRK as I have 400V phase-phase so need the 600V capacity? Based on this cut sheet?

Thanks so much!

Re: Simple question about voltage and current ratings [Re: piphomer] #208717 02/07/13 11:39 PM
Joined: Jul 2004
Posts: 9,394
G
gfretwell Offline
Member
If you have a 240v 3p with a 160a computed load the xx324xxx sounds like it is your panel with a 200a breaker using the appropriate conductors. If you had diversity and non continuous loads you could step down to 175a


Greg Fretwell
Re: Simple question about voltage and current ratings [Re: piphomer] #208724 02/08/13 07:11 AM
Joined: Jun 2004
Posts: 1,273
T
Tesla Offline
Member
piphomer: You're too green to be an EE, C-10 or certified electrician.

At this scale of power use -- turn the matter over to professionals.

There are too many issues for you to 'get it right' over the Internet.


Tesla
Re: Simple question about voltage and current ratings [Re: Tesla] #208732 02/08/13 03:34 PM
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Posts: 3
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piphomer Offline OP
New Member
Agreed. Thanks.


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