Quad breaker install for HPWC

[treemanzarek]

I buried my two questions in a wall of text in my previous post, so asking again more directly as I'm stuck.

I'm installing a 240V circuit for a wall charger. I want to get a permit, but looking at my sub-panel I think there are some issues, such as incorrect breaker types and double tapped breakers. Can anyone share their experience, in regards to inspectors picking on pre-existing issues unrelated to the specific permit in question? This is in Oakland, CA if that helps.

Secondly, I'm wondering if there is any reason I may not be able to install a quad breaker (kind of like 2x tandem breakers) in place of the two top left 20A breakers in the sub-panel. Is there any limitation in this type of Square-D bus bars which limits where tandem breakers can go?

Many thanks in advance.

Panel:

 

[Sophias_dad]

Can you get a close-up of the label on the panel and on the door? What size breaker is feeding this panel? Those feeder wires look pretty small.

 

[treemanzarek]

A 100A breaker from the main panel is feeding the sub. Here's the door and cover. I was under the house a while back, the feeder is broken (but not spliced) in two places and not in junction boxes. Carpentry is impeccable this house, electrical not so much. I will go read the gauge, didn't pick it up previously.

 

[treemanzarek]

The feeder is 2 AWG, I hope all the way since the last 15-20 ft is in a soffit.

 

[Sophias_dad]

HOMELINE Load Centers | Manualzz suggests that you can put a tandem breaker in every spot in that particular loadcenter, on page 10.

I believe the 185 amp maximum per branch circuit connector is referring to the two breakers on the same row of the box, which may actually represent FOUR circuits. If both are tandem breakers and at 50 amps each it would then then violate the 185 since 4x50 is 200. For your purposes with only 100 amps to play with, that's essentially a non-issue.

So I believe your plan is sound.

The box does look pretty bad, btw. The only extra comment I have is that I see the upper left pair has one red and one black wire. I assume that's because someone has used 12-3 wire to supply two separate ~20 amp 120V circuits using a common neutral. I'm not sure of the rules on those, but I have definitely seen them using duplex breakers in the past, even though they aren't feeding a 240v load. Doing a bit more research, that's called a MWBC, or MultiWire Branch Circuit, and IS supposed to have a handle-tie so if either breaker trips the other will.

 

[Rocky_H]

Secondly, I'm wondering if there is any reason I may not be able to install a quad breaker (kind of like 2x tandem breakers) in place of the two top left 20A breakers in the sub-panel. Is there any limitation in this type of Square-D bus bars which limits where tandem breakers can go?

I have an answer to a related question that you didn't quite ask. My panel is a Square-D Homeline type, and it is a model that WILL NOT take ANY tandem or quad type breakers at all. Period. And that is because of how the bus bars are built to block that. Specifically, the bus bars are long continuous horizontal bars that the breakers straddle onto when they snap in. The quads and tandems are built with very shallow cut notches in the ends of the breakers so they cannot snap all the way down onto those straight continuous bus bars.

The Square-D panels that are made to allow quads and tandems have the bus bars as these individual tabs that stick up in each breaker space, so that it's contained underneath the breaker when it snaps onto it.

I see that your panel already does have some quads and tandems in it, so these should be fine. I looked up the product datasheet for that panel, and it lists maximum number of tandem breakers as 6, so those are allowed. If it's just a matter of positioning, things can be rearranged to get them in the right places. Sometimes panels only allow the quad and tandems in several either top or bottom places, but that is usually marked on the data sheet on the metal door, and since it doesn't show any of that, I think these are probably OK in any position.

 

[treemanzarek]

Thanks so much @Sophias_dad , really appreciate you pulling the manual for the details. The top left two slots apparently supplied a 240V built in microwave (according to the label), which is now just a hood. So I have two single pole circuits now, one to the hood and the other to some counter plugs I think. Bad things happen when agents start prettying up a house for a sale .

Or, reading your guess more closely, you are correct and it was a lazy job from the start (sorry agents).

I really need to get a wiring diagram done for this house. And would like to replace the interior of the panel, it does have the corner slots slots for a longer 20 position load center, but that seems to be a nono.

Any thoughts on the permit question?

 

[treemanzarek]

Thanks for the additional info @Rocky_H, I feel good to turn off the power and see if my quad fits, sounds like it will.

 

[Sophias_dad]

Thanks so much @Sophias_dad , really appreciate you pulling the manual for the details. The top left two slots apparently supplied a 240V built in microwave (according to the label), which is now just a hood. So I have two single pole circuits now, one to the hood and the other to some counter plugs I think. Bad things happen when agents start prettying up a house for a sale .

Or, reading your guess more closely, you are correct and it was a lazy job from the start (sorry agents).

I really need to get a wiring diagram done for this house. And would like to replace the interior of the panel, it does have the corner slots slots for a longer 20 position load center, but that seems to be a nono.

Any thoughts on the permit question?

It does look like >maybe< you could replace the guts(and front panel, to get the proper label!) of this unit with the HOM20-24L125TC, but per that same link, the HOM20-24L125TC is only allowed to have tandem breakers in the lowermost four breakers, so you get the exact same number of circuits as the HOM12-24L125TC, although it would look nicer. I see one HOM2024L125TC on ebay, but it looks like it was designed with an unused main breaker space and won't physically fit the body of the 1224.

I think you won't have many problems with the permit. I see one double-tapped breaker, which you could fix with a wago 221 (or a wire nut if you wanna go old-school) in a couple minutes. In fact, several of the branch circuit wires in this box have several(or even many) inches of extra wire, and you could steal some of that excess and use that as a pigtail, and not even need to buy a foot of 12 gauge down at Home Depot.

The inspector will probably be more uptight about the MWBC not being properly tied than the double-tapped breaker, since the former is a potential safety issue. Consider getting a quad breaker that ties two 20's and two 50's(or whatever your new circuit draws).

I assume you've done a load calculation... with only 100 amps, I see a couple big breakers and I'd be surprised if you can put more than 30 amps of further load in there. The big breakers I see are apparently oven, cooktop, instant hot water, and it'd be easy to see them used all together.

Sadly, the 2 gauge feed wire is already at its limit even though the panel is rated to 125.

 

[EVer Hopeful]

This doesn't help but . . . I like the QO breakers


I'm too tired to take this in at the moment so I'll read it again tomorrow. One question though: what're the black and red wires that come out of the panel? I'm guessing it's the new service for the Wall Connector that you're installing

 

[treemanzarek]

It does look like >maybe< you could replace the guts(and front panel, to get the proper label!) of this unit with the HOM20-24L125TC, but per that same link, the HOM20-24L125TC is only allowed to have tandem breakers in the lowermost four breakers, so you get the exact same number of circuits as the HOM12-24L125TC, although it would look nicer. I see one HOM2024L125TC on ebay, but it looks like it was designed with an unused main breaker space and won't physically fit the body of the 1224.

I think you won't have many problems with the permit. I see one double-tapped breaker, which you could fix with a wago 221 (or a wire nut if you wanna go old-school) in a couple minutes. In fact, several of the branch circuit wires in this box have several(or even many) inches of extra wire, and you could steal some of that excess and use that as a pigtail, and not even need to buy a foot of 12 gauge down at Home Depot.

The inspector will probably be more uptight about the MWBC not being properly tied than the double-tapped breaker, since the former is a potential safety issue. Consider getting a quad breaker that ties two 20's and two 50's(or whatever your new circuit draws).

I assume you've done a load calculation... with only 100 amps, I see a couple big breakers and I'd be surprised if you can put more than 30 amps of further load in there. The big breakers I see are apparently oven, cooktop, instant hot water, and it'd be easy to see them used all together.

Sadly, the 2 gauge feed wire is already at its limit even though the panel is rated to 125.

Thanks, it seems to make sense to replace the guts, rather than rip out the whole thing (someday).

So I take it inspectors will raise issues with existing issues not related to the specific addition and I should fix them ahead of time? I already have the quad breaker without handles, will see if I can get one with both pairs tied. And can fix the double taps with pigtails. Also a few are Type MH-T breakers, one (top right) doesn't even snap in all the way. Any permit concerns with those?

If I can't get the breaker, maybe take a chance? Since you say it's a fire risk I probably wont, but if it's more of just a shock risk I may. They haven't been tied since I don't know when.

I haven't done a load calculation, didn't have all the volt-amp #s to plug in the formula. However, instant hot and trash compactor are no more. Cooktop (5 burners) and double oven running at hot is pretty rare, and I will charge overnight. Here are breaker #s - and the two top left 20A only supply a hood and counter plugs (microwave or electric kettle) respectively.

Left	Right
20 20 15 40 (DP) 40 (DP) 20/20	15/15 30 (DP) 30 (DP) 15 20/20 20/20

Thanks again for your time.

 

[treemanzarek]

This doesn't help but . . . I like the QO breakers


I'm too tired to take this in at the moment so I'll read it again tomorrow. One question though: what're the black and red wires that come out of the panel? I'm guessing it's the new service for the Wall Connector that you're installing

You are correct it's waiting ready to go. You can see the hookup in my other post.

 

[MY-Y]

One thing to watch out for. The red wire on the 120v breaker is likely a "multi-wire branch" circuit. It is critical that the breakers for the black and red wire for that circuit are on different legs, like they are now. If you use a tandem or rearrange the panel such that they are on the same leg, the currents add on the shared neutral instead of subtracting.

 

[Sophias_dad]

Thanks, it seems to make sense to replace the guts, rather than rip out the whole thing (someday).

So I take it inspectors will raise issues with existing issues not related to the specific addition and I should fix them ahead of time? I already have the quad breaker without handles, will see if I can get one with both pairs tied. And can fix the double taps with pigtails. Also a few are Type MH-T breakers, one (top right) doesn't even snap in all the way. Any permit concerns with those?

If I can't get the breaker, maybe take a chance? Since you say it's a fire risk I probably wont, but if it's more of just a shock risk I may. They haven't been tied since I don't know when.

I haven't done a load calculation, didn't have all the volt-amp #s to plug in the formula. However, instant hot and trash compactor are no more. Cooktop (5 burners) and double oven running at hot is pretty rare, and I will charge overnight. Here are breaker #s - and the two top left 20A only supply a hood and counter plugs (microwave or electric kettle) respectively.

Left	Right
20 20 15 40 (DP) 40 (DP) 20/20	15/15 30 (DP) 30 (DP) 15 20/20 20/20

Thanks again for your time.

Those MH-T breakers shouldn't even be in that loadcenter, which is why they don't fit. I'm surprised they are close enough to even plug in. They should definitely be replaced.

HOMT1515CP is the proper replacement for the breaker in the upper right. The correct one for the upper left is SQUARE D HOMT220250 MINIATURE CKT BRKR | Gordon Electric Supply, Inc..

Not tying the upper left MWBC is a shock risk, and a remote one at that. It is not a fire risk.

That hacky breaker in the lower right is also troubling. It looks like it may also be a MH-T, or even worse, only one of them is an MH-T.

 

[treemanzarek]

Those MH-T breakers shouldn't even be in that loadcenter, which is why they don't fit. I'm surprised they are close enough to even plug in. They should definitely be replaced.

HOMT1515CP is the proper replacement for the breaker in the upper right. The correct one for the upper left is SQUARE D HOMT220250 MINIATURE CKT BRKR | Gordon Electric Supply, Inc..

Not tying the upper left MWBC is a shock risk, and a remote one at that. It is not a fire risk.

That hacky breaker in the lower right is also troubling. It looks like it may also be a MH-T, or even worse, only one of them is an MH-T.

Thanks, I need to read better. You said safety risk, I read fire risk.

Yes, the lower right looks like another MWBC (now I know why they are tied), but one breaker is MH-T . Some of the MH-T breakers did fit all the way somehow. I will replace them. Probably need to do a load calculation if I expect to pass inspection, going to sleep in that part of the equation for a bit.