200 amp main breaker in 125amp panel?

So it's really not as dumb as it sounds. The panel is a square D sc2040m125pf. The sticker says Bussing is rated 225a max. Mains 125a max. And meter socket 125a max. The insulator behind the meter jaws says 200amp cont.... this panel is being installed as a "like for like" in my house that has a 125a panel currently. POCO said as long as the sticker says 125a max it is considered like for like. I guess my question is couldn't I install this panel now and when I'm ready for the service upgrade to 200a, install the underground raceway get the inspections and just swap the main to 200? BTW, Pocono already approved the like for like after seeing the sticker.
 

JFletcher

Senior Member
Location
Williamsburg, VA
So it's really not as dumb as it sounds. The panel is a square D sc2040m125pf. The sticker says Bussing is rated 225a max. Mains 125a max. And meter socket 125a max. The insulator behind the meter jaws says 200amp cont.... this panel is being installed as a "like for like" in my house that has a 125a panel currently. POCO said as long as the sticker says 125a max it is considered like for like. I guess my question is couldn't I install this panel now and when I'm ready for the service upgrade to 200a, install the underground raceway get the inspections and just swap the main to 200? BTW, Pocono already approved the like for like after seeing the sticker.

Welcome to the forum. The part I bolded is why you cant do what you suggest; even if a 200A mains breaker would physically fit the panel, you would have a 110.3(B) violation (listing) by supplying the panel with 200A service.
 

kwired

Electron manager
Location
NE Nebraska
If the manufacturer says 125 amp max how do you propose to install a 200 amp breaker

I got a dollar that says the manufacturer won't even make a 200a breaker that will physically fit onto the bus bars.

200 amp very well may fit.

Found this and it looks like all the products in that line probably use the QOM2 main breakers, if so up to 225 amp would fit. Something tells me the bus even if not marked so is probably 225 amp bus though.

Need an address where to send the dollar?:)

Paypal would take less percentage then a stamp will cost to send that dollar:huh:
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
200 amp very well may fit.

Found this and it looks like all the products in that line probably use the QOM2 main breakers, if so up to 225 amp would fit. Something tells me the bus even if not marked so is probably 225 amp bus though.

Need an address where to send the dollar?:)

Paypal would take less percentage then a stamp will cost to send that dollar:huh:

Just a minor detail, OP has Homeline, not QO.

Also, until it is attempted, we won't know if a 200 amp breaker will fit in a 125 amp panel. Sometimes breakers can look the same, but have different dimensions or be outfitted with rejection tabs.
 

kwired

Electron manager
Location
NE Nebraska
Just a minor detail, OP has Homeline, not QO.

Also, until it is attempted, we won't know if a 200 amp breaker will fit in a 125 amp panel. Sometimes breakers can look the same, but have different dimensions or be outfitted with rejection tabs.
Discussion is about the main breaker, both QO and Homeline use the QOM1/QOM2 series breakers for mains unless a "back fed" breaker is used as the main.

QOM1 is sizes from 50? through 125 amp.

QOM2 is sizes from 100 through 225 amp.

They are not interchangeable, a panel with 125 amp max bus will only accept the QOM1 series mains.

A panel with over 125 amp bus will accept the 100 amp or 125 amp QOM2 mains but will not accept a QOM1 main.

So if the main in the OP's situation has a 125 A QOM2 main - a 150, 175, 200 or 225 will physically interchange with it as they all have same physical dimensions. Whether the bus is actually same design as those more then 125 amps is not really known from catalog information only though.
 

480sparky

Senior Member
Location
Iowegia
200 amp very well may fit.

Found this and it looks like all the products in that line probably use the QOM2 main breakers, if so up to 225 amp would fit. Something tells me the bus even if not marked so is probably 225 amp bus though.

Need an address where to send the dollar?:)

Paypal would take less percentage then a stamp will cost to send that dollar:huh:

My dollar is pretty safe as I still don't see any breakers listed there that are 200a and fit on the bus bars.
 
The code reference to 110.3 was good. That would be in violation. I've just got this feeling that square D made all these panels capable of 225a then just slapped a sticker on it saying max 125a,150a etc. Pretty sure the QOM2 breaker will fit, but speaking of rejection tabs puts in reasonable doubt. I've still got another couple weeks before I swap the panels out so I guess I will buy the breaker and find out. Would there be anything else that could only be rated at 125a. If it's just a sticker issue I'm sure I can find one somewhere:angel:
 

kwired

Electron manager
Location
NE Nebraska
My dollar is pretty safe as I still don't see any breakers listed there that are 200a and fit on the bus bars.

QOM2 frame is same size for 100 thru 225 amps. Only reason it won't fit is if the 125 in the OP is actually a QOM1 frame size.

Seeing how all the other similar products are all over 125 amps, my bet is this one uses QOM2 main breaker as well, beyond that I have no idea if the bus in the panel is truly 125 amp bus or if it is same thing used in 225 amp panels but has a limitation because of what is on the label, but am leaning toward it being same construction as bus that is labeled for 225 amps.
 

JFletcher

Senior Member
Location
Williamsburg, VA
You're welcome to try, not my time and money. :D

The panels might be completely identical except for the mains lugs on the 125A panel could be smaller than the 200/225. You can believe if I were an engineer at SqD or elsewhere the 125A and 200A panels would NOT be physically identical guts-wise and only differentiated by a sticker and a listing.
 

kwired

Electron manager
Location
NE Nebraska
You're welcome to try, not my time and money. :D

The panels might be completely identical except for the mains lugs on the 125A panel could be smaller than the 200/225. You can believe if I were an engineer at SqD or elsewhere the 125A and 200A panels would NOT be physically identical guts-wise and only differentiated by a sticker and a listing.
I have installed enough Square D I can assure you all the QOM2 series breakers are physically identical other then trip settings.

Making several different but similar items costs less if all built on same base structure then to have a completely different base for everyone of them. Same for panel bus. For most part a main lug panel is either 125 or 225 amps. Now throw in a main breaker and all that makes the 100 different from the 125 or the 150 different from the 200 is the actual setting of the main breaker installed.

Why have to retool, reset machines, etc. because you are switching from making 150 to 200 amp panels - especially when you probably sell quite a few more 200 then 150 anyway?

I'm sure you will see some of this practice in other brands as well.
 

JFletcher

Senior Member
Location
Williamsburg, VA
I have installed enough Square D I can assure you all the QOM2 series breakers are physically identical other then trip settings.

Making several different but similar items costs less if all built on same base structure then to have a completely different base for everyone of them. Same for panel bus. For most part a main lug panel is either 125 or 225 amps. Now throw in a main breaker and all that makes the 100 different from the 125 or the 150 different from the 200 is the actual setting of the main breaker installed.

Why have to retool, reset machines, etc. because you are switching from making 150 to 200 amp panels - especially when you probably sell quite a few more 200 then 150 anyway?

I'm sure you will see some of this practice in other brands as well.

If any part of that panel is hand-assembled, I would include *some* physical means, other than a sticker for rating, of making them different, even if the lugs were it... that, or sell both panels at the same price.

Back to my original post tho... if this panel is labelled 125A, then regardless of how it's made, even if it's identical to a 200A, save the sticker, or included main breaker, running a 200A service to it in the future would be a 110.3(B) violation, yes?
 

kwired

Electron manager
Location
NE Nebraska
If any part of that panel is hand-assembled, I would include *some* physical means, other than a sticker for rating, of making them different, even if the lugs were it... that, or sell both panels at the same price.

Back to my original post tho... if this panel is labelled 125A, then regardless of how it's made, even if it's identical to a 200A, save the sticker, or included main breaker, running a 200A service to it in the future would be a 110.3(B) violation, yes?

What may be the only visible difference is the number stamped on the main breaker handle and the catalog number on the label affixed inside the panel.

I have never said it wasn't a violation to replace the 125 amp main with a 200, mostly because of the label fixed to the panel. I just have been trying to say that it is very possible that 125 amp panel actually has exact same bus inside as one with a 200 amp main breaker, they just don't tell you that.

What is the advantage of using same identical bus? Same part is made in bigger quantities instead of smaller batches of only slightly different parts but is used for more then one final product. If they were solid gold bus bars, raw material cost would definitely be a bigger factor. But for a Homeline panel we are talking about very insignificant cost difference in aluminum that gets tin plated for a 125 amp vs a 225 amp bus.
 
What may be the only visible difference is the number stamped on the main breaker handle and the catalog number on the label affixed inside the panel.

I have never said it wasn't a violation to replace the 125 amp main with a 200, mostly because of the label fixed to the panel. I just have been trying to say that it is very possible that 125 amp panel actually has exact same bus inside as one with a 200 amp main breaker, they just don't tell you that.

What is the advantage of using same identical bus? Same part is made in bigger quantities instead of smaller batches of only slightly different parts but is used for more then one final product. If they were solid gold bus bars, raw material cost would definitely be a bigger factor. But for a Homeline panel we are talking about very insignificant cost difference in aluminum that gets tin plated for a 125 amp vs a 225 amp bus.

You're correct here, as far as I know every single manufacturer uses the same density bussing for either 225A or 125A lighting panels.

However, anything outside of the rating of the panel, including changing the main device, voids the UL.
 

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
I don't know if it is said yet. The reason the bussing is rated at 225 is these are Solar Ready panels.

The main breaker is on opposite side unlike others
There is spot of CT measurements.
Stuff like that!
 

kwired

Electron manager
Location
NE Nebraska
All the products in the link I put in post 6 have 225 amp bus. One of them has the 125 amp main breaker, one of them has a 225 amp main breaker, the rest of them all have 200 amp main breakers.
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
So it's really not as dumb as it sounds. The panel is a square D sc2040m125pf. The sticker says Bussing is rated 225a max. Mains 125a max. And meter socket 125a max. The insulator behind the meter jaws says 200amp cont.... this panel is being installed as a "like for like" in my house that has a 125a panel currently. POCO said as long as the sticker says 125a max it is considered like for like. I guess my question is couldn't I install this panel now and when I'm ready for the service upgrade to 200a, install the underground raceway get the inspections and just swap the main to 200? BTW, Pocono already approved the like for like after seeing the sticker.

A better strategy might be to get the panel on which the sticker says 200A, swap a 125A breaker into it, and hold on to the factory 200A breaker for your later plans. I say 'might' because regardless you have to get poco and AHJ to agree.
 

kwired

Electron manager
Location
NE Nebraska
A better strategy might be to get the panel on which the sticker says 200A, swap a 125A breaker into it, and hold on to the factory 200A breaker for your later plans. I say 'might' because regardless you have to get poco and AHJ to agree.
Or follow the rules, bite the bullet and purchase the 200 amp now and install it properly.

Robbing Peter to pay Paul only works for so long before Peter and Paul catch on and make it more complicated.
 
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