How many circuit breakers in Square D panel

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mkgrady

Senior Member
Location
Massachusetts
Most load centers I see include a catalog number that indicates how many breakers can be put in the panel.. For instance a 30/40 panel has 30 spaces but ten of them can be the twin or mini breakers. I also often see a diagram that sows where the twins can be installed. If I don't see the diagram or the model number as described I just assume twim breakers are not allowed.

My question is: does Square D do it the same way?

This job has a QO panel with 30 spaces and already has a couple of twin breakers and I need to add a few more or add a subpanel. There is no diagram showing where twins can be installed and the model number indicates it is a 30 space panel with no indication that it can be increased.
 

Dennis Alwon

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Location
Chapel Hill, NC
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Retired Electrical Contractor
Sure Sq. D has panels with twins but without the info I am not sure how you can tell. Some panels have a means to stop twins but sq. D has a few style piggyback breakers
 

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
I tend to agree with Dennis. One of the tip-offs is the panel cover. Some of the older Square D panels are shown like this in the panel directory :

_____________

-----------------
_____________

Usually if it has that dotted line between the solid lines it will accept piggy-backed breakers. The problem you'll run into is that there usually aren't enough spots to land neutrals and grounds on the neutral bar. The other problem you have with these older panels is trough space on the sides and bottom. If someone else has already added piggy-backed breakers I'd bet there isn't mush space or unused KO's available. It's your call - you may have to make some field modifications and add a sub-panel.
 

jim dungar

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Staff member
Location
Wisconsin
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PE (Retired) - Power Systems
My question is: does Square D do it the same way?

Yes.


The tandem breakers without the rejection tab, are only for use in panels built before UL had a CTL provision, roughly the early 1960's.
But even back then the panel directories showed which locations were intended for use with tandem breakers.
 
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mkgrady

Senior Member
Location
Massachusetts
Based on the answers above I conclude that this panel should not have tandem breakers. I will add a subpanel to remove the ones already there and for the additional new circuits. Thanks for the responses.
 

hurk27

Senior Member
Yes.


The tandem breakers with the rejection tab, are only for use in panels built before UL had a CTL provision, roughly the early 1960's.
But even back then the panel directories showed which locations were intended for use with tandem breakers.

Jim older panels and tandems before CTL's didn't have the rejection and could be put anywhere in a panel with replacements having a label on them that stated "For replacement use only" (unless you meant "without the rejection tab" back then I have never seen anything in these older panel labels that said anything about only using certin spaces, as a mater of fact, as was pointed out Square D's labels all had two spaces some times marked A&B as if they allowed tandems??

CTL tandems had the rejection and will only fit into select slots of a panel made to use CTL's tandem's

QO's had the hook in the back of the tandem that wouldn't allow it to go in a regular slot because the rail didn't have a hole for it, Home Lines have the shorter stab slot that will only go into the notched buss slots.

What I never figured out is most all manufactures including Square D make non-CTL breakers, even the Home Line one's can be purchased as non CTL even though Home lines came out well after CTL's were in the code, ITE also has non-CTL tandems for panels that were out under the ITE brand name long after CTL's were in the code book.

The whole reason UL started limiting how many breakers in a panel was because of a hotel fire that was ruled to be caused by an over heating panel board, UL started limiting panel boards to 42 over current devices, but I thought that was removed from the code in 2008 cycle which was the third time they moved the requirement from 408.15 in the 2002 to 408.35 in the 2005 to 408.54 in the 2008, in the 2008 version they changed the wording to put the manufacture back in control of designing the panel board to have more over current devices but kept the wording that the manufacture must provide means to limit the amount of over current devices to which the panel board is design for, I have seen a couple boards that would allow 54 breakers but these were 400 amp boards.

As far as I know older non-CTL panels are grand fathered in to having non-CTL tandems, I have seen many that had nothing but tandems.

The other thing I never understood on this finding is if a breaker can get hot enough to cause a fire it would seem that the thermo element would have long since tripped so how can it ever cause a fire? I don't know how many times I have had panel boards with breakers tripping because they were running hot, mostly outdoor panels in direct sunlight, get a breaker hot enough and it will trip without even having a load, so how did they ever come to that conclusion in the hotel fire?

Even if tha panel board was found to be the source of the fire I would have looked at if the panel board had a main and if the bus was over loaded, or were the breakers magnetic trip only, both of which would not have anything to do with todays breaker designs and the fact the bus has to be protected at its current rating.
 
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jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
Jim older panels and tandems before CTL's didn't have the rejection and could be put anywhere in a panel with replacements having a label on them that stated "For replacement use only"

Not quite.

Even before CTL, the panels had specific locations for tandem breakers, though the breakers did physically fit everywhere.
When I started selling them, back in 1978, we called the non-rejection tandems, 'cheater breakers', because we knew why they were being bought.

I cannot find a non-CTL version of HomeLine on the Schneider Electric website, even though many supplier websites say they exist.
 

hurk27

Senior Member
Not quite.

Even before CTL, the panels had specific locations for tandem breakers, though the breakers did physically fit everywhere.
When I started selling them, back in 1978, we called the non-rejection tandems, 'cheater breakers', because we knew why they were being bought.

I cannot find a non-CTL version of HomeLine on the Schneider Electric website, even though many supplier websites say they exist.

Sorry I did some editing after your post, but my responce to your post was because you said "tandems with the rejection tab could only be used in the older panels", but I think you meant "without"

I still ask why Square D always put two lines on these older non-CTL panel boards for each breaker space sometimes even labeling them as "A" and "B" to me would seem like saying tandems were ok?
 
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curt swartz

Electrical Contractor - San Jose, CA
Location
San Jose, CA
Occupation
Electrical Contractor
Not quite.

Even before CTL, the panels had specific locations for tandem breakers, though the breakers did physically fit everywhere.
When I started selling them, back in 1978, we called the non-rejection tandems, 'cheater breakers', because we knew why they were being bought.

I cannot find a non-CTL version of HomeLine on the Schneider Electric website, even though many supplier websites say they exist.

Homeline didn't even exist before the late 80's. The is no such thing as a non CTL version of HOM breakers.
 

jim dungar

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Location
Wisconsin
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PE (Retired) - Power Systems
Sorry I did some editing after your post, but my responce to your post was because you said "tandems with the rejection tab could only be used in the older panels", but I think you meant "without"
Good catch. I just went back and edited it.

I still ask why Square D always put two lines on these older non-CTL panel boards for each breaker space sometimes even labeling them as "A" and "B" to me would seem like saying tandems were ok?
If that is what the directory showed, then every location could accept tandems, like a 'QO816' can.
 

curt swartz

Electrical Contractor - San Jose, CA
Location
San Jose, CA
Occupation
Electrical Contractor
Sorry I did some editing after your post, but my responce to your post was because you said "tandems with the rejection tab could only be used in the older panels", but I think you meant "without"

I still ask why Square D always put two lines on these older non-CTL panel boards for each breaker space sometimes even labeling them as "A" and "B" to me would seem like saying tandems were ok?

Wayne, are you refering to the lines on the cover? If so QO loadcenters don't include covers. You have to purchase the covers seperately. One cover may fit many different loadcenters so the labeling is generic. That is one reason you never assume there are available spaces even though breaker KO's are available with QO equipment. Many times it may look like spaces are avaialble but once you pull the cover there are not any buss fingers behind the spaces.
 

PetrosA

Senior Member
... That is one reason you never assume there are available spaces even though breaker KO's are available with QO equipment. Many times it may look like spaces are avaialble but once you pull the cover there are not any buss fingers behind the spaces.

One of the reason why I dislike QO panels in the first place (aside from the goofy neutral bars and crappy screw connections for the neutral lugs). I recently, for the first time in a long time, installed a QO panel as a sub panel. I only moved one circuit that day but the panel cover already had the two top knock-outs for breakers removed. Goofy.
 

hurk27

Senior Member
Wayne, are you referring to the lines on the cover? If so QO loadcenters don't include covers. You have to purchase the covers separately. One cover may fit many different loadcenters so the labeling is generic. That is one reason you never assume there are available spaces even though breaker KO's are available with QO equipment. Many times it may look like spaces are available but once you pull the cover there are not any buss fingers behind the spaces.

I agree that Square D uses the same cover for many models of panels, but I have no idea how they came back in the "60's" but today we always get the cover included in the box with the panel at least around here we do.

I wonder if your supply house is removing the cover and selling it separately trying to make extra money???? it does come in its own box inside of the main box the panel comes in? go to any big box store and you will find the cover included.

I have seen many QO 16/32 panels come with a 20 space cover, and yes you think wow I have 4 extra spaces only to find that the buss doesn't extend that far:rant:

Another goofy issue with Square D both home line and QO is if you buy the main breaker panel you get the separate EGC bars already installed in them, if you buy a ML version you have to buy them separately, never understood that one.
 
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hurk27

Senior Member
One of the reason why I dislike QO panels in the first place (aside from the goofy neutral bars and crappy screw connections for the neutral lugs). I recently, for the first time in a long time, installed a QO panel as a sub panel. I only moved one circuit that day but the panel cover already had the two top knock-outs for breakers removed. Goofy.

I mount many of my panels with the main at the bottom to save wire when bottom fed and it can be a pain if you want to start your breaker at the top because you have those two K/O's knock out already, I just use them for the GFCI I mount below the panel and or the circuit for the room the panel is in.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
I agree that Square D uses the same cover for many models of panels, but I have no idea how they came back in the "60's" but today we always get the cover included in the box with the panel at least around here we do.

I wonder if your supply house is removing the cover and selling it separately trying to make extra money???? it does come in its own box inside of the main box the panel comes in? go to any big box store and you will find the cover included.

I have seen many QO 16/32 panels come with a 20 space cover, and yes you think wow I have 4 extra spaces only to find that the buss doesn't extend that far:rant:

Another goofy issue with Square D both home line and QO is if you buy the main breaker panel you get the separate EGC bars already installed in them, if you buy a ML version you have to buy them separately, never understood that one.

Loadcenters sold at electrical wholesale distributors are typically packaged with the trim as a separate item. Loadcenters sold at 'home centers' are typically packaged with the cover. Different markets, different methods. Also, most products sold at DIY and big box stores have the suffix CP in the part number which indicates their method of packaging and their sales channel.
 

kwired

Electron manager
Location
NE Nebraska
Jim older panels and tandems before CTL's didn't have the rejection and could be put anywhere in a panel with replacements having a label on them that stated "For replacement use only" (unless you meant "without the rejection tab" back then I have never seen anything in these older panel labels that said anything about only using certin spaces, as a mater of fact, as was pointed out Square D's labels all had two spaces some times marked A&B as if they allowed tandems??

CTL tandems had the rejection and will only fit into select slots of a panel made to use CTL's tandem's

QO's had the hook in the back of the tandem that wouldn't allow it to go in a regular slot because the rail didn't have a hole for it, Home Lines have the shorter stab slot that will only go into the notched buss slots.

What I never figured out is most all manufactures including Square D make non-CTL breakers, even the Home Line one's can be purchased as non CTL even though Home lines came out well after CTL's were in the code, ITE also has non-CTL tandems for panels that were out under the ITE brand name long after CTL's were in the code book.

The whole reason UL started limiting how many breakers in a panel was because of a hotel fire that was ruled to be caused by an over heating panel board, UL started limiting panel boards to 42 over current devices, but I thought that was removed from the code in 2008 cycle which was the third time they moved the requirement from 408.15 in the 2002 to 408.35 in the 2005 to 408.54 in the 2008, in the 2008 version they changed the wording to put the manufacture back in control of designing the panel board to have more over current devices but kept the wording that the manufacture must provide means to limit the amount of over current devices to which the panel board is design for, I have seen a couple boards that would allow 54 breakers but these were 400 amp boards.

As far as I know older non-CTL panels are grand fathered in to having non-CTL tandems, I have seen many that had nothing but tandems.

The other thing I never understood on this finding is if a breaker can get hot enough to cause a fire it would seem that the thermo element would have long since tripped so how can it ever cause a fire? I don't know how many times I have had panel boards with breakers tripping because they were running hot, mostly outdoor panels in direct sunlight, get a breaker hot enough and it will trip without even having a load, so how did they ever come to that conclusion in the hotel fire?

Even if tha panel board was found to be the source of the fire I would have looked at if the panel board had a main and if the bus was over loaded, or were the breakers magnetic trip only, both of which would not have anything to do with todays breaker designs and the fact the bus has to be protected at its current rating.
Maybe the hotel fire had FPE panels:)

Not quite.

Even before CTL, the panels had specific locations for tandem breakers, though the breakers did physically fit everywhere.
When I started selling them, back in 1978, we called the non-rejection tandems, 'cheater breakers', because we knew why they were being bought.

I cannot find a non-CTL version of HomeLine on the Schneider Electric website, even though many supplier websites say they exist.
Maybe they are not genuine Square D products.

Sorry I did some editing after your post, but my responce to your post was because you said "tandems with the rejection tab could only be used in the older panels", but I think you meant "without"

I still ask why Square D always put two lines on these older non-CTL panel boards for each breaker space sometimes even labeling them as "A" and "B" to me would seem like saying tandems were ok?

Been answered already - Covers fit more than one panel. The cover for a 30/40 panel is same catalog number as the cover for a straight 30 circuit panel.

I agree that Square D uses the same cover for many models of panels, but I have no idea how they came back in the "60's" but today we always get the cover included in the box with the panel at least around here we do.

I wonder if your supply house is removing the cover and selling it separately trying to make extra money???? it does come in its own box inside of the main box the panel comes in? go to any big box store and you will find the cover included.

I have seen many QO 16/32 panels come with a 20 space cover, and yes you think wow I have 4 extra spaces only to find that the buss doesn't extend that far:rant:

Another goofy issue with Square D both home line and QO is if you buy the main breaker panel you get the separate EGC bars already installed in them, if you buy a ML version you have to buy them separately, never understood that one.

Also been answered, big box stores purchase them with modifications to the standard catalog items.
All big box panels come with a "combination" flush/surface cover, which is really just the flush cover. Purchase panel from a supply house and you must purchase a flush or surface cover separately. Supply house main breaker panels have no additioinal grounding bars included, but main lug panels do come with an additional grounding bar - as they should. That is for QO series, Homeline series from a supply house is more like the packaging contents of a big box store panel, they do come with a cover. I haven't purchased that many Homeline panels from supply house to know for certain what is common with them. I primarily install QO panels.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Loadcenters sold at electrical wholesale distributors are typically packaged with the trim as a separate item. Loadcenters sold at 'home centers' are typically packaged with the cover. Different markets, different methods. Also, most products sold at DIY and big box stores have the suffix CP in the part number which indicates their method of packaging and their sales channel.
Possibly one motivation there is to keep the DIY purchaser from buying just the load center and never installing a cover. :)
Would not pass inspection, but this may not be work done under a permit. :)
 
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