Tandem breakers don't sit flush in panel

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Old 03-13-09, 01:44 PM
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Tandem breakers don't sit flush in panel

I have three tandem breakers that do not sit properly. I assume this means they are in slots not intended for tandem breakers, right? Or maybe just installation error? Unfortunately, I see nothing in the panel that says whether or not tandem breakers are allowed and if so, where. It's a Square D Homeline Cat No. HOMC30UC, Series S1. I can't seem to find the specs. Can anybody help me out?

The tandems were installed by the previous owner. These three that aren't sitting flush are the only tandems in the panel, by the way. Panel is totally full, rated 150 Amps. FWIW, I had three different electricians tell me it wasn't a big deal when I was getting bids for other jobs. I don't know if that's true or not. It tells me that the the previous work, a basement finishing job, probably wasn't inspected.

 
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Old 03-13-09, 02:42 PM
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Looking at the picture and how the breakers are sitting I would bet that the panel is not rated for the tandem breakers.

The reason they are sitting like that is there is not a notch in the bus bar of the panel to accept the tandem breaker correctly.
Looking at your Catalog number doesn't look like it is rated for tandem breakers either.
 
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Old 03-13-09, 02:49 PM
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Yeah, those are definitely wrong; there is no way those are seated properly. Do you space beside the panel to add a subpanel?
 
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Old 03-13-09, 02:58 PM
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Originally Posted by ibpooks View Post
Yeah, those are definitely wrong; there is no way those are seated properly. Do you space beside the panel to add a subpanel?
Is there any chance that there are slots in this panel that WILL take tandem breakers? I thought I read that panels that take tandems typically only have a few such slots, while the others only take singles.

I can probably do a subpanel. Do you know the spacing requirements for that? How far does the panel and subpanel have to be from other things?
 
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Old 03-13-09, 03:09 PM
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Originally Posted by jumpyg View Post
Is there any chance that there are slots in this panel that WILL take tandem breakers?
I doubt it. Usually the panels that accept tandems are in the bottom slots. Clearly your bottom slots cannot take tandems.

I can probably do a subpanel. Do you know the spacing requirements for that? How far does the panel and subpanel have to be from other things?
30" side-to-side, 36" deep. The 30" side-to-side clearance can overlap with the other panel. The panels only need to be far enough apart so the covers don't touch (6" conduit nipple is just fine).
 
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Old 03-13-09, 04:55 PM
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The Square D 30 space panel is only for 30 circuits. It won't accept tandems anywhere in it.

I'll tell you this though, if you decide to upgrade to 200 amps. The Square D 200 amp 30/40 load center will be the exact can and cover and you can just swap out the "guts". They are also the same in those panels except the main breakers.
 
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Old 03-13-09, 04:58 PM
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Something strikes me funny about that picture.

Arent the "mounting feet" on a tandem --ACROSS from the busbars?????----Which would move the breakers toward the Center if they were forced in? It also appears from the pic, that the breakers may be slightly wider than the others...... Did you accidentally buy Homelines instead of QO's?---The bus bar mounts are different and would easily account for the difference in "DEPTH"

** Sorry ..Did you buy QO's instead of Hom's ***
 
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Old 03-13-09, 07:33 PM
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I have seen this happen before but not sure if they were Homeline breakers. Pull one of the regular breakers out and one of the tandems out. Flip both of them upside down and compare the slots on them where they slap into the busbar. I bet the slot is much larger on the regular breaker compare to the tandem breaker. There is alittle more plastic covering the slot on the tandem most of the time due to flash from the molding of the breaker. Look hard and if so most of the time you can chip away that plastic so the slot is the same as the regular breaker you have that fits. If not sure send us a picture with a regular breaker and one of the tandem breakers.

Jim Beer 4U2
 
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Old 03-14-09, 01:45 AM
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The quickest way to verify if that load centre can take tandaem breaker or not is read the catalog numbers like example HOM30M150 that mean that is Homeline 30 space 150 amp main breaker however here is the next example

HOM30/40M150 it mean HOM 30 fullsized breaker or 10 tandem breakers and 20 full sized breakers.

If you took the cover off and look at the bussbar the tandem verison will have notched bussbar in the centre while full size do not have any notches at all and what more the tandem breaker have diffrent " nose " than standard full size breaker some case it will have rejecting cam in there as well

That photo show that is very serious issue it need to be addressed asap for safety reason due the breaker bussbar clip is limited concat it can get overheated and destory a perfectally good load centre.

Merci,Marc
 
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