# 320 amp rating



## ralph (Apr 6, 2008)

I have a question. If the 400 Amp service has a solid load of at least 320 amps or more, does anyone think that the meter that has a rating of 320 amps will have a problem ? Usually, our " 400 amp " sevices don't seem to have much more of a 200 + amp load. Actually, 99 % of the time it is just fed with two pieces of 4/0 al SE or SER depending on locations.
I have a service to install on a remodel/addition. In a perfect world, a 600 amp service would be a nice sell. Maybe use a I line nema 3 enclosure with three disconnect breakers, one for each location,( there are three panels to be fed) but the builder wants to keep the cost down. 
Trying to figure out what kind of problems a large load will cause on the power company's meter, if any.
Thanks in advance for any input.


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## papaotis (Jun 8, 2013)

you say 'usually ' , do the calculation for your current project


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## BBQ (Nov 16, 2010)

Up to 400 amps for periods up to 3 hours, only 320 amps for loads longer than 3 hours.




> *Continuous Load.* A load where the maximum current is
> expected to continue for 3 hours or more.


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## ralph (Apr 6, 2008)

I do. 
Seem to get a little too general I guess when typing. Ive done a bunch of 400 's, but all loads always calculate low it seems.
This one is coming in alittle heavier. Of course the project is changing weekly it seems, which doesn't help matters.


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## papaotis (Jun 8, 2013)

ralph said:


> I do.
> Seem to get a little too general I guess when typing. Ive done a bunch of 400 's, but all loads always calculate low it seems.
> This one is coming in alittle heavier. Of course the project is changing weekly it seems, which doesn't help matters.


not daily? lucky you!:laughing:


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## ralph (Apr 6, 2008)

That's a good point. Not daily. That would stink


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## mbednarik (Oct 10, 2011)

a 320 socket is rated at continuous duty.
http://www.milbankworks.com/blog/wp-content/uploads/2013/03/1797.pdf


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## McClary’s Electrical (Feb 21, 2009)

ralph said:


> I do.
> Seem to get a little too general I guess when typing. Ive done a bunch of 400 's, but all loads always calculate low it seems.
> This one is coming in alittle heavier. Of course the project is changing weekly it seems, which doesn't help matters.


Set a 400 amp bolt on meter. Run 600 mcm al into a trough. Tap that 600 three times and set (3) 200 amp disconnects. Take the feeders wherever you like.


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## mbednarik (Oct 10, 2011)

Never seen one, utilities around here allow a 320 or the next step is to CT.


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## McClary’s Electrical (Feb 21, 2009)

mbednarik said:


> Never seen one, utilities around here allow a 320 or the next step is to CT.


Around Herr the 320's stab in and the 400's bolt on.


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## sparky402 (Oct 15, 2013)

mbednarik said:


> Never seen one, utilities around here allow a 320 or the next step is to CT.











Something like this


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## DIYer4Life (Nov 11, 2013)

I still don't understand the 320/400A service thing.

Does a 200A service have a 160A continuous rating?

Jeeze, I'll never figure this out


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## Going_Commando (Oct 1, 2011)

DIYer4Life said:


> I still don't understand the 320/400A service thing. Does a 200A service have a 160A continuous rating? Jeeze, I'll never figure this out


One day you'll figure it out, rookie.


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## hardworkingstiff (Jan 22, 2007)

sparky402 said:


> View attachment 31803
> 
> 
> Something like this


That looks nice there 402. I especially like the expansion couplings under the CT cabinet. It's amazing how many people don't do that around here (even more amazing they get by with not doing it).


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## BBQ (Nov 16, 2010)

DIYer4Life said:


> Does a 200A service have a 160A continuous rating?


If you are using standard off the shelf loadcenters the answer to your question is yes. 


You would have to use 100% rated equipment to get a 200 amp continuos rating from a 200 amp panel.

We recently did an 800 amp service with a 100% rated breaker.


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## BBQ (Nov 16, 2010)

sparky402 said:


> View attachment 31803
> 
> 
> Something like this


It blows my mind that areas still use that style of CT cabinet. 

Around here we use CT cabs that have built in terminals and bus bars to bolt the CTs too. No need to run the conductors through a donut CT.


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## hardworkingstiff (Jan 22, 2007)

Is it just me or does that CT cabinet look out of square, like it's contorted?


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## BBQ (Nov 16, 2010)

hardworkingstiff said:


> Is it just me or does that CT cabinet look out of square, like it's contorted?


I think it is just the angle of the picture, the motor joints look like they run down hill as well.


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## sbrn33 (Mar 15, 2007)

You can buy a 400 amp continuous rated socket. If your worried just do that. I would not be to worried though.


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## BBQ (Nov 16, 2010)

sbrn33 said:


> You can buy a 400 amp continuous rated socket. If your worried just do that. I would not be to worried though.


Unless you do the same with the service equipment it would be a waste of money.


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## sparky402 (Oct 15, 2013)

hardworkingstiff said:


> That looks nice there 402. I especially like the expansion couplings under the CT cabinet. It's amazing how many people don't do that around here (even more amazing they get by with not doing it).


Thanks. Our inspectors wont pass it without the expansion fittings


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## Meadow (Jan 14, 2011)

BBQ said:


> If you are using standard off the shelf loadcenters the answer to your question is yes.
> 
> 
> You would have to use 100% rated equipment to get a 200 amp continuos rating from a 200 amp panel.
> ...


 
Most off the shelf load centers have a buss rating of 225amps.


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