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bltglt507 12-03-2009 12:02 AM

Problems with Square D Subpanel
I have some concerns that I would like to express about the Square D Homeline Subpanels. About a year and a half ago, I installed a Square D subpanel and ran 50 AMP service to it. I didn't encounter any problems mounting it or installing the 6/3 cable, but I ran into problems when I installed 2 Tandem breakers. I went to install the Tandems in the subpanel, but I encountered great difficulty in getting them to install all the way. After using a great amount of force to push them in, they finally went. About a year ago, I inspected the subpanel and discovered that one of the plastic tabs that helps hold the breakers in broke off and was laying at the bottom of the subpanel. The tandem however doesn't fall out because it grips so hard to the hot bar. The first question I have is, has anyone else encountered a problem such as this with these kinds of breakers? The second problem I encountered with this subpanel has to do with the hot bus bar. When I inspected the subpanel, I also discovered that one of the two screws that holds the top hot bus bar in place had broken loose. The hot wire screwed to the hot plate had a slight kink in it, but I wouldn't have thought that would have caused problems, but it did. I screwed the screw back in, which didn't seem to fasten tightly so I spread a bunch of JB Weld where the hot bus bar and the plastic backing come in contact to hold it in place, since then it hasn't came loose. To make sure and avoid this problem, I also de-rated the Subpanel to 30 AMPs with 10/3 cable, which is smaller and doesn't place as much stress on the hot bus bar. What makes me nervous is the fact that this subpanel could handle 100 AMP service, if 6 awg cable can break this screw loose, I can only image what damage 2 awg cable could do. My second question is, has anyone encountered a problem like this? It seems to me that Square D's Homeline subpanels are not made very well. These problems I've encountered seem strange. I've searched all over the internet and haven't heard of anything like this, although I've heard of similar stories such as broken neutral bars.

frenchelectrican 12-03-2009 12:18 AM

First thing first.,

can you run the model number by me ?

The reason why due I know some load centre can allow twinners or tandams and some don't

The reason why you have push super hard due you have tandam breaker in wrong spot if they are allowed you have to look at the chart normally it will have diffrent busbar shape more like notched in the centre of busbar tab that is the place it will allowed tandam in there if no notch then you can NOT install the tandam just like you try to force it hard.

I think the issue is you have improper toqure that can get pretty common curpit with any load centre brand name

For Homeline I do get broken neturalbuss bar but not super common but the bracket yeah I have see it.

The QO seems do not have much issue compared to HOM series.

So let me know the model number I can able tell ya what is safe and not and i will fill the rest of details in a bit after you post the load centre model number.


kbsparky 12-03-2009 03:01 AM

A couple of issues comes to mind:

1) Inserting those tandem breakers can be a chore at times -- they have to be installed in a certain way, and the clearance tolerances are quite tight. Even for a professional like me, I do have to ensure that the breaker foot is properly inserted and aligned before the jaws will engage the bus bar all the way. That being said, forcing the breaker to seat will only cause damage, and I do not recommend doing so.

2) IF by some chance you attempt to install a different brand of breaker, such as an ITE/Siemens/Murray, or Cutler-Hammer BR or BD type, it won't seat fully onto the bus bar assembly, and forcing that can cause the bars to deform, or other damage.

Can you post a closeup picture of your particular panel showing the damage?

Jim Port 12-03-2009 07:41 AM

Without a model number I am thinking the Op tried to install a tandem where none was meant to be used.

I would replace the panel guts instead of the JB weld fix.

220/221 12-03-2009 06:52 PM


I screwed the screw back in, which didn't seem to fasten tightly so I spread a bunch of JB Weld

:no::jester::wink: That's as far as I got.

bltglt507 12-03-2009 07:56 PM

Model No. HOM6-12L100
The model number is HOM6-12L100, it has 6 spaces and says it can handle 12 circuits. Therefore, it can handle Tandem Breakers. If you own the book Guide to Wiring by Black and Decker, the same type of box is shown on the 3rd or 4th page with Tandems installed. I took the panel cover off today and examined it more thoroughly. The Tandem breaker that is in the spot with the missing guide hook is in place and is mounted even with the other breakers. I don't think I mentioned this, but I have 4 regular breakers in addition to the 2 tandems, and all of the breakers are sitting even with each other. Since this experience with Tandems, I've decided to avoid using them unless absolutely necessary. I've also had another encounter with tandems that have convinced me to avoid them, shortly after I installed this subpanel, I tried to install a tandem in our main breaker box. I didn't realize it, but it was not designed to handle Tandems. The breaker wouldn't go in all the way, so I just assumed that it must be stubborn like the ones in the subpanel, so I did a very foolish thing and started tapping it in with a hammer. It finally went all the way in, but a few days later I ran across a post on the internet about how tandems don't always fit certain boxes. That is when I realized my mistake, and I took the tandem out of the box and replaced it with a regular breaker and redesigned my circuit plans. I don't think it did any damage to the main box, but I've learned from these experiences. It seems to me that there needs to be a big sticker or label that specifically says "Tandems Allowed" or "Tandems Not Allowed."

bltglt507 12-03-2009 08:17 PM

Subpanel Photos
4 Attachment(s)
Attachment 15216

Attachment 15214

Attachment 15213

Attachment 15215

I've attached 4 photos of the subpanel, I hope they uploaded successfully.

bltglt507 12-03-2009 08:20 PM

The left screw was the one that broke loose. It didn't fall out, it just sort of hung out and the left side of the busbar was protruding outwards. The right screw never broke loose, but I spread JB Weld over both just to make sure they stayed in, JB Weld is non-conductive by the way. The second tandem breaker from the left is the one that popped the guide hook out.

Jim Port 12-03-2009 09:00 PM

I don't see how the torque from a #6 would have been able to damage the buss.

I would recommend the guts be replaced.

Did you also install an auxillary ground buss?

bltglt507 12-03-2009 09:05 PM

The ground wires are attached to a grounding bar that is separate from the neutrals. May I ask why exactly you would recommend replacing the core part of the box, as I have to admit I haven't encountered any major problems with the box for about a year?

bltglt507 12-03-2009 09:40 PM

Also... I measured the thickness of the plastic, and it is about 1/4 of an inch thick, which means the screw for the hot bar would only be able to go in about 1/8 of an inch, as it would have to be kept away from touching the back of the subpanel. With the screw only going in that short of length and it being screwed into plastic, not metal, that is probably the reason why a big 6awg cable over time slowly put pressure on it and worked the screw loose. I don't really know if this is that big of a deal or not, but I would like input from several professionals before I decide whether to take action or not. In a few days, I plan to have some electricians install a bathroom heater, I'll also show them this issue and get their input. I appreciate the replies that I have received so far.

Scuba_Dave 12-03-2009 09:56 PM

I'm not an electrician...but If I were & saw the insides of that panel I would not install any circuit in it unless the guts were replaced

bltglt507 12-03-2009 10:58 PM

If I did choose to replace the main part of the subpanel, would I have to buy another one identical to it and unscrew and replace the main part? Is there any risk in damaging the core components of a new subpanel by removing them and placing them in the old subpanel? I have to admit, after this debacle, I'm don't fully trust the durability and ruggedness of these electrical devices.

bltglt507 12-04-2009 01:32 PM

1 Attachment(s)
Attachment 15219

Problem Solved.
Took about 45 minutes to replace.
The electricians that installed a heater said it was probably o.k. but recommended replacement. After I removed the old part, I looked on the back of it and the screw that holds the hot plate in had not gone through the plastic, so it wasn't as dangerous as it appeared. When I screwed the new part in, I made sure everything was snug but not overtightened. I do feel better however knowing that everything is like it should be.

300zx 12-04-2009 05:31 PM

Sorry to say but that Square D subpanel Looks like a Mess :yes: in that last pic.

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