400amp Combo Service

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HoosierSparky

HoosierSparky

Senior Plans Examiner, MEP
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Scottsdale AZ
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Senior Plans Examiner
SqD_400a_Service.jpgOne of my buddies found this new electric service. It is a Sq D CU12L400CN. The single pole breakers at the top buss go to enclosed garage recepts and lights. The 2p 80 feeds a pool sub-panel. The 2p 30 feeds an A/C disconnect(non-fused). The contractor cannot understand why is installation is wrong. Can anyone else explain it to him?:blink:
 
It would be interesting to see the diagram on the cover.
Looking up that catalog in the Square-D Digest it appears the entire creature has been severely altered including the removal of a main breaker.
 
augie47 said:
It would be interesting to see the diagram on the cover.
Looking up that catalog in the Square-D Digest it appears the entire creature has been severely altered including the removal of a main breaker.
Click to expand...

There does not appear to be anything wrong with the panel itself.
The Square D Digest says this 400A panel is rated for (1) factory installed 200A breaker, (1) field installed 200A max breaker, and (4) 2-pole 125A max breakers (200A total load).
The picture, in the Digest, is not specific to this catalog number.

The only visible problem, is the use of 1-pole breakers that Masterinbama pointed out.
 
Some observations

Some observations

We did notice the 7 disconnects off the meter. The buss is listed for a max of 4 125amp breakers. They did mix the short-circuit ratings of the breakers in the panel. The panel is listed at 25k. The two 200a mains in the bottom are 22k, the breakers on the buss are 10k. The breakers per SqD shall be SERVICE RATED and branch circuit breakers shall not be used. The singles should not be there. :angel:
 
jim dungar said:
There does not appear to be anything wrong with the panel itself.
The Square D Digest says this 400A panel is rated for (1) factory installed 200A breaker, (1) field installed 200A max breaker, and (4) 2-pole 125A max breakers (200A total load).
The picture, in the Digest, is not specific to this catalog number.

The only visible problem, is the use of 1-pole breakers that Masterinbama pointed out.
Click to expand...

You are the "Digest" expert so I won't challenge that.
The way that top buss was in the OP's post made me suspicious, so I entered the catalog number in the on-line Digest and got this:
http://www.downloads.schneider-elec...636&p_Conf=i#http://www.schneider-electric.us

It showed a single main, but, as you say it may not be specific to that particular panel.
 
augie47 said:
You are the "Digest" expert so I won't challenge that.
The way that top buss was in the OP's post made me suspicious, so I entered the catalog number in the on-line Digest and got this:
http://www.downloads.schneider-elec...636&p_Conf=i#http://www.schneider-electric.us

It showed a single main, but, as you say it may not be specific to that particular panel.
Click to expand...

The handout on your link, does not list the OP's catalog number.
Try this one for a CU12L400CN.
http://www.schneider-electric.com/p...ice-entrance-devices-cseds/60251-meter-mains/
Then select the Donwload & Documents link, finally choose from the CAD option.
 
HoosierSparky said:
View attachment 8817One of my buddies found this new electric service. It is a Sq D CU12L400CN. The single pole breakers at the top buss go to enclosed garage recepts and lights. The 2p 80 feeds a pool sub-panel. The 2p 30 feeds an A/C disconnect(non-fused). The contractor cannot understand why is installation is wrong. Can anyone else explain it to him?:blink:
Click to expand...

Looks like all of the breakers are off of the meter secondary, so they all become service disconnects. Limit is six, per Code.
 
jim dungar said:
There does not appear to be anything wrong with the panel itself.
The Square D Digest says this 400A panel is rated for (1) factory installed 200A breaker, (1) field installed 200A max breaker, and (4) 2-pole 125A max breakers (200A total load).
The picture, in the Digest, is not specific to this catalog number.

The only visible problem, is the use of 1-pole breakers that Masterinbama pointed out.
Click to expand...
The 200 amp breaker on the right is the factory installed one. They bend the 3/0 with the hard 90's at the factory. When you install the other 200 in the field your wire is straight from the lugs to the line side.
 
I'm sorry, but what is the problem with the sp's being in there? Is it solely because you're in violation of the 6 disc rule or is it something else?
 
mark32 said:
I'm sorry, but what is the problem with the sp's being in there? Is it solely because you're in violation of the 6 disc rule or is it something else?
Click to expand...
It has to do with UL Listings and service entrance requirements.

Schneider Electric FAQ website:
Can a single pole breaker be used on a Combination Service Entrance Device?
A single pole breaker can be used as a branch device in the loadcenter section (if applicable) of a CSED device. Only two pole breakers are UL listed to be used as main disconnects.
 
jim dungar said:
It has to do with UL Listings and service entrance requirements.

Schneider Electric FAQ website:
Can a single pole breaker be used on a Combination Service Entrance Device?
A single pole breaker can be used as a branch device in the loadcenter section (if applicable) of a CSED device. Only two pole breakers are UL listed to be used as main disconnects.
Click to expand...

Thanks Jim, are the single poles considered "Main disconnects" because there is no main ahead of them, because they are obviously protecting branch circuits.
 
Jim, would you agree that this listing is unique to this panel? In other words, if one installs a panel and it's service rated, couldn't you normally use sp's, dbl poles, or a combination of them and be code compliant as long as you have six or less handles? Let's say you install a service rated mlo panel in a separate structure and use two double poles and four single poles, that's normally compliant correct?
 
mark32 said:
I'm sorry, but what is the problem with the sp's being in there? Is it solely because you're in violation of the 6 disc rule or is it something else?
Click to expand...

Before 2008(?) NEC it also would have been a problem because installing just one single pole unit made it become a lighting and appliance panelboard and a the panelboard would then have required a single main.

jim dungar said:
It has to do with UL Listings and service entrance requirements.

Schneider Electric FAQ website:
Can a single pole breaker be used on a Combination Service Entrance Device?
A single pole breaker can be used as a branch device in the loadcenter section (if applicable) of a CSED device. Only two pole breakers are UL listed to be used as main disconnects.
Click to expand...

I will trust you on the listing information, otherwise it would be NEC compliant oustide of listing instructions.
 
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