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150A breaker

woodrail

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So I'm not having any luck looking this up, and my head is starting to hurt.....

I'm installing a sub-panel in the dettached shop. I was planning on using #2 wire to give me 100 amp. I was able to acquire #1 instead. I figure I'm safe to install 150amp instead.

My understanding is that I need a 150 amp breaker in my main 200amp panel. Will #1 wire directly tap into this breaker? This wire is BIG!

I'm bringing in a buddy to help me that knows what he is doing, but I'm just curious.

Thanks!
 
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pattenp

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#1 Cu or #1 Al should not be used for 150A. #1 Cu is 130A @ 75C and #1 Al is 100A @ 75C. You can do 125A or 100A breaker respectively in the main service panel. The sub-panel can be a 200A.

The amps you're stating is if it's a service to a dwelling providing the full load. That doesn't apply in this case.
 
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ishiboo

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As patten said, your thoughts are incorrect.

You also didn't mention a panel brand, but a Square D 150A breaker (pricey!) is good for up to 300 kcmil... much larger than #1.

You also didn't mention if you "managed to acquire" copper or aluminum, the length of the run, how the wire is getting there, etc.
 
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woodrail

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Sorry, The wire was removed from a similar sub panel run. I didn't steal it!

First off, I made an error in the sizing. The wire is 1/0 AWG THWN in 1.5" Armorflex. The run is about 50 feet. 30 feet will be indoor using the armorflex, the remaining 20 will be in a 2" conduit underground and up to the detached garage panel.

The main panel is 200A Square D I beleive. The sub has not been purchased yet.

Thanks fior any advice.
 
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woodrail

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Wire is three conductor #1/0. I understand I need to add a ground conductor, right? Probably a #6 or can I use a #8?
 

pattenp

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Yes you need the ground conductor. Over 100A and up to 200A you need at minimum a #6 copper or #4 aluminum for the equipment ground. You still didn't specify if the wire you have is aluminum or copper.
 

madosta

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Yes you need the ground conductor. Over 100A and up to 200A you need at minimum a #6 copper or #4 aluminum for the equipment ground. You still didn't specify if the wire you have is aluminum or copper.

Probably copper... was 450' - scrapped 400'!

HAHA JK! ;-P
 
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woodrail

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OK, let's try this again. Will the 1/0 wire tap directly into a 150A breaker? Assume Square D.

Thanks.
 

pattenp

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OK, let's try this again. Will the 1/0 wire tap directly into a 150A breaker? Assume Square D.

Thanks.

If you're asking will 1/0 fit a 150A breaker, the answer is yes. If you are functionally asking if the 1/0 can be fed by a 150A breaker in the main service panel, the answer is yes. Not totally sure what you're asking by saying directly tap.

Edit: You need to verify that your main panel can take a 150A breaker for a branch circuit. The limit may be 100A.

*
 
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ishiboo

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OK, let's try this again. Will the 1/0 wire tap directly into a 150A breaker? Assume Square D.

Thanks.

Yes, as I said... the 150A Square D (Homeline/QO) is good for up to 300 kcmil. 1/0 is smaller than 2/0 which is smaller than 3/0 which is smaller than 4/0 which is smaller than anything measured in kcmils. :) So you are good to go.
 
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woodrail

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ok! got it. thanks. I had no idea what 300 kcmil was! I thought that was a rating, not a size.

My worry was that that size of wire (1/0) would physically not be able to attach to the breaker.

I will get into the main box and pull the specs reguarding the largest breaker possible.

I need to finish up some other stuff first before I do this project.

Thanks to all who answer.
 
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930dreamer

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Question on the Armorflex. How long of a run can you go with this stuff. An EE at work said it's purpose was for very short length? ie a disconnect to a gang box etc?

I have a 30' run from my main service going to a disconnect.

Thanks
 

pattenp

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http://www.lowes.com/pd_140277-296-HOM2150BB_0__?productId=3467881

Is this what I should be looking for? I've seen those $300 jobs. I hope I don't need one of those!

You better ****** it up for that price. That breaker elsewhere is $200+. Here's one of the cheaper prices I've seen.

http://www.amazon.com/dp/B008HK7PE4/?tag=atomicindus08-20

Here's a different one for $107....
http://www.zorotools.com/g/00009805...medium=referral&utm_campaign=AmazonProductAds

I've seen incorrect pricing on Lowes.com before, so you may want to purchase it now. I got a Dewalt Inspection Camera from Lowes.com just a short while ago for $189 because it was way cheaper than I could find anywhere. The next day after my purchase the price changed to $299.
 
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Norcal

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A panel may not allow a 150A breaker to be installed, a lot of them have a limit of 110A per bus stab, read the label to see if it's allowed...............
 

Speedy Petey

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A panel may not allow a 150A breaker to be installed, a lot of them have a limit of 110A per bus stab, read the label to see if it's allowed...............
I was waiting for this, and I agree. Most panels are rated for up to 125A per stab.

That said, I have never seen that 4-pole 150A (75A parallel) breaker before. That would certainly get around this issue.
 

ishiboo

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I was waiting for this, and I agree. Most panels are rated for up to 125A per stab.

That said, I have never seen that 4-pole 150A (75A parallel) breaker before. That would certainly get around this issue.

Yes, no issues with using that on a 200A box.

In addition, IMO, even if the stabs were rated for 200A, I don't believe 1/0 let alone 300kcmil belongs on only two stabs/breakers. If not dressed PERFECTLY that is a TON of pressure on the thermoplastic that holds everything together.
 

Charles (in GA)

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A user still has to verify it is allowed.

I agree. It should be listed on the placard on the inside of the door.

On page 17/72 (document page 15) of THIS CATALOG the 150, 175 and 200 amp breakers are listed with two footnotes. The one relevant to this discussion says... "Requires four spaces (#1–300 kcmil Al/Cu). Use only in single phase panel rated 150 A or greater."

For whatever reason, Schneider does not seem to keep their web site up to date, as this catalog is a 2004 and the load center catalog is a 2007. you would think there is something newer.

Charles
 
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Charles (in GA)

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Yes, no issues with using that on a 200A box.

In addition, IMO, even if the stabs were rated for 200A, I don't believe 1/0 let alone 300kcmil belongs on only two stabs/breakers. If not dressed PERFECTLY that is a TON of pressure on the thermoplastic that holds everything together.

The wires just about need to enter the panel from the side at the point where the breaker is located and go directly onto the breaker terminals, with no bends.

Making heavy wire form and stay in shape in a panel is real work, which I why I have suggested a number of times in the past to use a panel larger than you really need, simply for the working room.

Charles
 
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