Tandem breaker allowance help

Thank you, Jim.

As Jim stated you would count the number of circuit breaker poles installed in the panel. A tandem CB only requires one slot but would still count as two poles.

1 Like

Interesting that the six throw rule for disconnect means would have counted the 6 2 poles as six, but if a branch circuit they would count as 12.

You’re correct but it would be 6 throws of the hand.

Morning, Jim. The 6 throw rules is in regards to disconnecting the service, not circuits.
The NEC has permitted up to ‘six service disconnects’ in ‘a single enclosure’ for decades.
IRC 2003 Old IRC code but i is all I have.
E3501.6 Service disconnect required . A means shall be provided to disconnect all conductors in a building or other structure from the service entrance conductors.
Hope that helps.
Still digesting on the CB poles rules. Thanks for the rules, Jim and Robert.

Robert, I was aware of that rule and requirements. I was just pointing out the difference between throws of the hand vs breaker pole count. Two ways of looking at the same breaker.

Not from what I understand.
230.71(A)]) that a service must have have ‘a main disconnect’ that shuts off all power and it cannot take more than six switch throws to do it.
Subpanels are not required to have a main disconnect, with one exception.

Please, excuse my repetitive posts OP and members. This thread has unique to me and I can not seem to let it go. Great learning tool OP. I thank you all for your replies.

I know this is an ambiguous question Jim, but why do you think that manufacturers omit a pole count?
Could it be for the very same reason I have been eluding to. Electric Panel Labels indicate maximum circuits allowed, not poles.

I found at article that to me was worth the read. What is the maximum number of circuit breakers allowed in an electric panel?
Not What It Used To Be
The answer to this question was once very simple. The National Electrical Code (NEC) specified that a lighting and appliance branch circuit panelboard could not contain more than 42 overcurrent devices (circuit breakers). That was the absolute maximum, unless the manufacturer specified a lower number, which was often the case for smaller panel boxes.
I hope this helps members.

Kind regards.

I think you need to consider the code article posted by RM that says a 2 pole counts as two circuits, vs looking at it as a single 240 volt circuit . I think you are also being thrown off by the numbers on the directory vs the number the panel is listed for.

It is hard to read the cat number for the panel but it looks like your panel is a square D Homeline Panel. If this is correct, it is for 20 FULL SIZE SPACES. Each space is 1 inch.
Your panel has several tandem (Cheater Breakers). These allow 2 circuits using one inch space.
Here is a link to help you get more information. Look at the pic of the busbar with the split. Current panels will only have some of the split so you do not overload your panel.

1 Like

I have a similar problem. I read thru this thread and truthfully, I am just as confused as I was before reading it.

Are these tandems allowed? Thanks in advance.
(I did observed multiple different breaker manufacturers as well)

It looks to me like the bottom 5 openings on both sides allow for tandem breakers:



Yes, according to your photo’s 10 tandem CB’s are permitted in the bottom 5 slots on each side. For newer panels you can confirm this by checking the breaker schematic as Larry pointed out and also the catalog number. In this case the cat number is SL15(20-30)CT, 20 full size slots with 10 being suitable for tandem CB’s, maximum 30 circuits.

1 Like

Thank you @lkage and @rmeier2 !!

1 Like