Having my first senior moment here

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laketime

laketime

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I am figuring out the service for a residence. I have calculated the VA the house will require by code. I=P/E. Is the E 120v or 220v? I think it should be 220v but that comes out to 50 amps for a 5,421 sq ft house. Am I doing something wrong?
 
Be right back with the answer but I gotta find my teeth first. Last time I lost 'em they were in the frige next to the milk.:grin:
 
laketime said:
I am figuring out the service for a residence. I have calculated the VA the house will require by code. I=P/E. Is the E 120v or 220v? I think it should be 220v but that comes out to 50 amps for a 5,421 sq ft house. Am I doing something wrong?
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Something sounds wrong but you would use 240volts.

Go to Mike Holts Site and click on the residential load calculator.
 
Make sure you're not using the optional method, it will usually come out lower.

You must be missing something. The calc in the back of the NEC is for a 1500 sqft house and it shows 77.5 amps.

The nice thing about senior moments is that now, at least, you have something to blame it on.
 
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cowboyjwc said:
Make sure you're not using the optional method, it will usually come out lower.

You must be missing something. The calc in the back of the NEC is for a 1500 sqft house and it shows 60.6 amps.

The nice thing about senior moments is that now, at least, you have something to blame it on.
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Yeah used to blame them on to many reggae concerts!;)
 
mcclary's electrical said:
Yes, if there's a breaker.

I'm saying you could have a disconnect rated at 100 amps, install 60 amp fuses, and it would be legal service.

The wording may not match the intent, but that's what I read


(on a side note, I pretty much do a 200 min.)
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I don't buy it- I know Bob and other's do but IMO it says disconnect. It doesn't say the disconnect enclosure or buss. To me the fuses would be the disconnect and would violate this article.

Now what about the 6 breaker rule? Not sure but I would still install 100 amp wire. I don't think you will find many inspectors to buy into this interpretation. I don't.:grin:
 
Dennis Alwon said:
I don't buy it- I know Bob and other's do but IMO it says disconnect. It doesn't say the disconnect enclosure or buss. To me the fuses would be the disconnect and would violate this article.

Now what about the 6 breaker rule? Not sure but I would still install 100 amp wire. I don't think you will find many inspectors to buy into this interpretation. I don't.:grin:
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Nor would I try:D


but that's what it says. And a fuse alone is not a disconnecting means.
 
Dennis Alwon said:
I don't buy it- I know Bob and other's do but IMO it says disconnect. It doesn't say the disconnect enclosure or buss. To me the fuses would be the disconnect and would violate this article.

Now what about the 6 breaker rule? Not sure but I would still install 100 amp wire. I don't think you will find many inspectors to buy into this interpretation. I don't.
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The OCP is permitted to be adjacent to the switch, need not be integral 230.91. Just need a 100 amp switch, next to a cut-out cabinet ;).


mcclary's electrical said:
Nor would I try:D
but that's what it says...
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Me either, but I'd debate it here . . . :roll: :grin:.
 
I'm back but I can't stay. I found my teeth ok. They were in the bread box. Thing is I misplaced my glasses and can't really see well enoughto type a good answer to the OP's question. Be right back after I find my glasses.
 
I did start with square footage 5421x3=16263
first 3000va is 100%
rest is derated at 35% of total va
 
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