# Tandem breakers in a new panel



## 480sparky (Sep 20, 2007)

1900 said:


> Excuse my ignorance of the code and my lack of ambition to figure it out myself. I got an old 60A sub panel with 11 circuits that I want to replace. I would like a simple Square D QO panel, but the only smaller panels they make are 6 space 12 circuit panels.
> 
> I can't use a full size panel because the position of the current panel and feeder pipe are in a stud hollow that is only about 13".
> 
> I read and heard that you can't use tandem breakers in new panel installations, is this true?


Depends on the panel.

Took at the instructions for it and it will tell you how many spaces and how many circuits can be installed. If the numbers are the same, you can't install tandems. If the latter is larger than the former, (such as 20/30 or 20/40) then you can.

Some manufacturers put that information in the model number as well. For instance, a MCB22003030 panel cannot accept tandems, but a MCB22003040 can.

Would a Sawzall help?


----------



## 1900 (May 4, 2009)

480sparky said:


> Depends on the panel.
> 
> Took at the instructions for it and it will tell you how many spaces and how many circuits can be installed. If the numbers are the same, you can't install tandems. If the latter is larger than the former, (such as 20/30 or 20/40) then you can.
> 
> ...


Thanks for the response!

The panels I was looking at say 6 spaces 12 circuits so I know I could use tandem breakers. But I thought you weren't allowed to use tandem breakers on new installations, only when adding in the future (something about using the correct size panel in the first place?). That's what I read, I don't know how true it is, maybe just a local thing?

The sawzall is a good idea :thumbsup:, but I got plaster walls and don't feel like opening them up and cutting into, then having to header off load bearing studs.


----------



## Bob Badger (Apr 19, 2009)

1900 said:


> But I thought you weren't allowed to use tandem breakers on new installations, only when adding in the future


Unless there is a local amendment saying otherwise, you can fill them to the limit on the day you install the panel. Some people use the 20/40 panels entirely filled with twins.


----------



## 1900 (May 4, 2009)

Bob Badger said:


> Unless there is a local amendment saying otherwise, you can fill them to the limit on the day you install the panel. Some people use the 20/40 panels entirely filled with twins.


 Good enough, thank you sir!


----------



## miller_elex (Jan 25, 2008)

Don't forget to notch the bus on panels with more spaces,
after that 42 limit went away, I could add twins all up and down a bus!!


----------



## 480sparky (Sep 20, 2007)

miller_elex said:


> Don't forget to notch the bus on panels with more spaces,
> after that 42 limit went away, I could add twins all up and down a bus!!


 
Um, not really.


----------



## bobelectric (Feb 24, 2007)

They should look into outlawing G.E.200 amp 20/40 panels ,rather than a.f.c.i.requirements.


----------



## MDShunk (Jan 7, 2007)

I happen to prefer the brands that use 3/4" breakers (CH-CH and QO). Those tandems are about 4 to 5 times the price of a single pole, so you need a really good reason to want to use one. The 1" tandem breakers (which I don't happen to favor, like HOM, Siemens, CH-BR, etc) are only twice the price of a single pole. Using a tandem 1" breaker probably does make good sense in that case, since the "price per pole" is the same whether you're using a single pole or a tandem .

I don't use much GE, except on service calls, but that whole half-size breaker thing is just too much like FPE for me to ever like. If a GE breaker goes bad, you can almost bet money it's the half-size version.


----------



## 1900 (May 4, 2009)

miller_elex said:


> Don't forget to notch the bus on panels with more spaces,
> after that 42 limit went away, I could add twins all up and down a bus!!


Wouldn't that be a 110.3(B) violation?


----------



## MDShunk (Jan 7, 2007)

1900 said:


> Wouldn't that be a 110.3(B) violation?


Of course it would be. He's talking crazy. Not sure if he believes what he wrote or not. 

Unless the manufacturers come out with some sort of bus notching tool to notch it to exacting specs (they won't), you can't just hack up a panel bus. That's just nuts.


----------



## 1900 (May 4, 2009)

MDShunk said:


> I happen to prefer the brands that use 3/4" breakers (CH-CH and QO). Those tandems are about 4 to 5 times the price of a single pole, so you need a really good reason to want to use one. The 1" tandem breakers (which I don't happen to favor, like HOM, Siemens, CH-BR, etc) are only twice the price of a single pole. Using a tandem 1" breaker probably does make good sense in that case, since the "price per pole" is the same whether you're using a single pole or a tandem .
> 
> I don't use much GE, except on service calls, but that whole half-size breaker thing is just too much like FPE for me to ever like. If a GE breaker goes bad, you can almost bet money it's the half-size version.


The only reason I am looking to use tandems is for space issues where the panel needs to be located.

The QO breakers are either $5 each for single poles or $17 each for tandems. So per circuit a single pole is $5 while a tandem is $8.50. Since there will only be 5 tandems, the difference in price isn't too bad.


----------



## MDShunk (Jan 7, 2007)

1900 said:


> The only reason I am looking to use tandems is for space issues where the panel needs to be located.
> 
> The QO breakers are either $5 each for single poles or $17 each for tandems. So per circuit a single pole is $5 while a tandem is $8.50. Since there will only be 5 tandems, the difference in price isn't too bad.


Seriously? Are they CTL or non-CTL tandems for 17 bucks? My guess is that a panel of the size you talk about isn't going to legally take tandems, and to use them you'd have to cheat and go with the non-CTL variety. The non-CTL tandems are a lot more expensive.


----------



## 1900 (May 4, 2009)

MDShunk said:


> Seriously? Are they CTL or non-CTL tandems for 17 bucks? My guess is that a panel of the size you talk about isn't going to legally take tandems, and to use them you'd have to cheat and go with the non-CTL variety. The non-CTL tandems are a lot more expensive.


The QO CTL breakers at Home Depot are $17. The non-CTL are in a plastic blister pack over the the side and cost over $30.

The QO panels I am looking at are 6 space 12 circuit panels that Home Depot stocks, or (if I could find it) the 8 space 16 circuit panel. These panels will accept tandems, they have the notch for the hook to fit inside of.


----------



## MDShunk (Jan 7, 2007)

1900 said:


> The QO panels I am looking at are 6 space 12 circuit panels that Home Depot stocks, or (if I could find it) the 8 space 16 circuit panel. These panels will accept tandems, they have the notch for the hook to fit inside of.


Really? Awesome. I didn't know they made a 6/12. Looks like you have a plan. Looks like you can use the cheaper CTL rated tandems. 

Is it rated for use as service equipment, or does it need to be in your application? Nevermind... I see in your original post that it's a sub .


----------



## user4818 (Jan 15, 2009)

I may have modified CTL breakers into non-CTL breakers in the past. :whistling2:


----------



## MDShunk (Jan 7, 2007)

Peter D said:


> I may have modified CTL breakers into non-CTL breakers in the past. :whistling2:


Some of them are pretty easy. I think it was Westinghouse that you just pulled a little metal clip out of the breaker with needle-nose pliers. I think that HOM you have to actually hack on the bus to make it fit. I don't really put too much effort into that type of thing. Normally pretty easy to add a sub. More profitable, at least.


----------



## 1900 (May 4, 2009)

MDShunk said:


> Really? Awesome. I didn't know they made a 6/12. Looks like you have a plan. Looks like you can use the cheaper CTL rated tandems.
> 
> Is it rated for use as service equipment, or does it need to be in your application? Nevermind... I see in your original post that it's a sub .


 If you're interested, Square D's website has a panel finder thingie, you can enter in your specs and it will show you what they have. All the smaller 6/12, 8/16, 20/40 etc. panels are listed.


----------



## user4818 (Jan 15, 2009)

MDShunk said:


> Normally pretty easy to add a sub. More profitable, at least.


Well, duh! 

But sometimes you gotta do what you gotta do.


----------



## MDShunk (Jan 7, 2007)

1900 said:


> If you're interested, Square D's website has a panel finder thingie, you can enter in your specs and it will show you what they have. All the smaller 6/12, 8/16, 20/40 etc. panels are listed.


Got a link?


----------



## MDShunk (Jan 7, 2007)

peter d said:


> well, duh!
> 
> but sometimes you gotta do what you gotta do.


10-4


----------



## 1900 (May 4, 2009)

MDShunk said:


> Got a link?


 http://www.schneider-electric.us/pr...cts/load-centers/residential/qo-load-centers/
Click on the Product Selector tab.


Also, if you go to their home page, then Products, then choose Loadcenters you can find product selectors for other types of panels and enclosures.


----------

