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#27490 - 07/18/03 09:27 AM What size service above 200 AMP?  
Happi_Man  Offline
Joined: Jun 2002
Posts: 206
Columbus, Ohio - USA
The houses we wire are usually 3000 - 3500 square ft. We use a SQD QO 200 AMP 40 SPC 40 Circuit panel. We keep our circuits light and usually come close to filling up the panel. If they finish the basement we set a 100 AMP sub.

We are about to do a house that is slightly over 4000 sq ft and we know that the 200 AMP is not going to be enough. Our idea was to use a 225 AMP panel (3/0 Copper SEU) and a 100 AMP sub.

My question is - is there a better way?

One suggestion I got was to use 12 wire everywhere and load up on 20 AMP circuits. Then you can set a 200 AMP service. WOuld anyone in their right mind use more 12 wire than necessary?

Open to more suggestions. Thanks.

Work Gear for Electricians and the Trades

#27491 - 07/18/03 10:43 AM Re: What size service above 200 AMP?  
ThinkGood  Offline
Joined: Aug 2002
Posts: 1,081
Milwaukee, WI
My [non-electrician] 2ยข:

Would dividing things up and using sub-panels help any by shortening the lenghths of cable run?

#27492 - 07/18/03 01:00 PM Re: What size service above 200 AMP?  
Electric Eagle  Offline
Joined: Apr 2002
Posts: 914
Alpharetta, GA
If the heat is non-electric and the water is gas, you probably are still OK to use a 200 amp service with a sub. A better way would be to install a 300 or 400 amp service, giving you either 2 -150 amp panels or 2- 200 amp panels. But that starts running the cost up. Is this a bid job or will the owner/builder listen to why this would be better? I've always found with homeowners that they want the ability to expand and if you tell them that they'll be maxed out with 200, they'll go for the 400.

#27493 - 07/18/03 01:11 PM Re: What size service above 200 AMP?  
straightedge  Offline
Joined: Mar 2002
Posts: 86
Mesa, AZ
I would use a 400-amp meter panel combo with two 200-amp disconnect breakers. that gives you one 200-amp panel connected with the meter combo. Then you can use a 1 1/2" or 2" nipple to connect another 200-amp sub panel right next to it.
That should give you plenty of circuit breaker space.

#27494 - 07/18/03 01:27 PM Re: What size service above 200 AMP?  
Tom  Offline
Joined: Jan 2001
Posts: 1,044
Shinnston, WV USA
Instead of coughing up the extra $$$ & labor and guessing, try doing one of the calculations to determine the size of the service. Once you get a little practice, the calculation does not take very long, Residential wiring can be a real cut-throat business & you could end up pricing yourself out of some jobs.

That said, I'd go with a 400 amp meter base & two 200 amp MCB panels mounted next to each other. As Straightedge pointed out, plenty of circuit availability.


Few things are harder to put up with than the annoyance of a good example.

#27495 - 07/18/03 02:54 PM Re: What size service above 200 AMP?  
SJT  Offline
Joined: Jul 2002
Posts: 241
Do they allow a 150A, and a 200A, main ckt. breaker on a 320amp service?

#27496 - 07/18/03 06:54 PM Re: What size service above 200 AMP?  
Active 1  Offline
Joined: Feb 2003
Posts: 687
Grayslake IL, USA
We would allways take a 400 amp meter base and pipe them with 2" rigid and 3ott wire seperate into two 200 amp panels with main beraker. That is what I see others do here too. The only inspection problem we had was disagreements about what ground wire size to use.

I don't know if much would be saved with a 150 amp panel instead of a 200 amp. I know the meter pedistals come in 200 and 400 amp but I have not seen a 300 amp one. They allways say at the supply house that the more something sells the better deal it is. Example a 5/8" round rod is cheaper than a 1/2".

I had seen a 400 amp comercial panel with a 200 amp sub but it just seemed like a more expensive way to go.

One guy that that loved to spend money on his new home had us put in a switch gear panel on his 400 amp service. Then he had four 200 amp 42 space bolt in breaker panels around the house (one was for his generator).

Our utility allways uses a 320 amp meter on a 400 amp home service. I think they just figure the service at 80%.

#27497 - 07/20/03 12:58 PM Re: What size service above 200 AMP?  
DougW  Offline
Joined: Jun 2003
Posts: 1,143
North Chicago, IL
400A meter to (2) 200A MCB's, nippled together with (1) 1 1/4", and several 3/4". Probably about 2-3" separation, just enough for the front covers to meet.

We just did a job like this. Go big (standard sizes are cheaper) or stay home [Linked Image]

BTW, when I first started re-wiring my house (before I got into the biz), I used 12awg cu on everything, thinking "bigger is better". Of course, I was also running combo light/wall receptacle circuits due to limited # of CB's in panel, so I figured WTH.

(My friend (an alarm installer - used to low voltage stuff) just ran 10 awg (s) cu through 1/2" LQT FMC when converting our buddy's garage to a "hot tub room". I looked at him like he was mental, and asked him "how many air compressors and fire pumps he was going to run". I got the reply "bigger is better". I shook my head, told him "as long as you're the one pulling it", and went back to wiring the 240 D/C for the tub...

[This message has been edited by DougW (edited 07-20-2003).]

#27498 - 07/20/03 02:25 PM Re: What size service above 200 AMP?  
arseegee  Offline
Joined: Jan 2002
Posts: 324
Statesboro, GA USA
Thread Jack on the 14awg vs 12awg. I use nothing but 12awg. I feel you get more out of it and less voltage drop. I dont allow devices to be "poke" connected so even if i used the #14 there would be no time savings on trim out.

Its funny, i go to another town and it's ALL 14 except on the kit counters, bathrooms and laundry circuits. Maybe I am overkill but I go real light on the connected loads too. No more than 1800VA on a lighting circuit and no more than 8 recepts on a general recept cicuit.

Am i nuts.... or just doing a good job?

#27499 - 07/20/03 05:10 PM Re: What size service above 200 AMP?  
Electric Eagle  Offline
Joined: Apr 2002
Posts: 914
Alpharetta, GA
I think you're nuts! And I think you're doing a good job.

We use a lot more 12 than most contractors, but we still use 14 for general circuits. We give each bathroom its own GFCI circuit(except for the 1/2 baths)

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