I have a Square D electrical panel in my home. This particular manufacturer produces tandem circut breakers (2 circut breakers in the same size unit as a single pole breaker).
The advantage is that you get to add 2 new circuts but use only 1 space in the panel. Are there any disadvantages or code issues when using these breakers?
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Replies
There are code limits on the number of circuits you can have in one residential panel. And remember that both circuits are on the same phase when using a wafer breaker.
..personally I'm not a big fan of tandems ..
but the Mfrs. restrict the number of them in any panel , so folks can't turn a 20 circuit panel into a 40
and the circuits on tandems need seperate neutrals..
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., wer ist jetzt der Idiot ?
Edited 5/13/2007 11:07 am by maddog3
Seperate neutrals or the breaker needs to be tied together like a 220. Or am I confused?
"Without education, we are in a horrible and deadly danger of taking educated people seriously." G.K. Chesterton
http://thewoodwhisperer.com/
You are confused. It would only be 220 if the second breaker was on the other hot line. With two breakers feeding off one post, say the "red" one, if you snip the neutral and touched the two together you would get... nothing. They are part of the same wire so there is no addition of voltage.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Parenting has always been a mix of sage life advice and inexcusable laziness.
I'm thinking electric code. If you have two breakers sharing a neutral then you are supposed to tie them together. Like a 220. Ooops wait a minute. I think thats just if they come into the same box together at the other end.
Never mind me. I'm just having a moment.:)
"Without education, we are in a horrible and deadly danger of taking educated people seriously." G.K. Chesterton
http://thewoodwhisperer.com/
I am not sure what you where thinking (nor not thinking as the case might be).But there is also a QUAD breaker.That is 2 pair of tamden breakers mounted side by side. The inner two have a tie bar for 240. And some also have a tie bar around the outside pair.Looking at SQ D catalog the best that I could figure in that the homeline comes as an assemble of 2 tandems.For QO there was an assemble for one common current ratings, but you could get individiual tandems and tie bar kits..
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
no 220 , not on one tandem, but I'm sure somebody has tried it using two tandems.
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., wer ist jetzt der Idiot ?
Yea I've got my head together now. I don't know what I was thinking. Back to earth now. Carry on.
"Without education, we are in a horrible and deadly danger of taking educated people seriously." G.K. Chesterton
http://thewoodwhisperer.com/
Be aware that there are two styles of Sq D panels, and two styles of tandem breakers. Get the right one for your panel. Also, as noted, Sq D restricts the number of pole spaces that can accomodate a tandem breaker, so chose the space that will work.
Frank DuVal
I have found that the tandems are not as good if your circuits are loaded to the max( 16 amps on a 20 amp breaker, for instance). The heat generated by the loaded condition will cause the breaker to trip prematurely. They seem to work OK for intermittent loads or for lightly loaded circuits.
As others have mentioned, the tandems may not fit every where in the panel, as the manufacturer has limited the total number of circuits.
Chuck
Threads like this scare the b..jesus out of me.
Oh, I can add a piggy back breaker and not spend the money to do it the safe way.
Do you sleep in this house? Have you done the load calculations to see what the panel/service can handle? Is it already overloaded?
You have people on this thread talking about 16 amp breakers???? I have never heard of a 16 amp breaker?
Edited 5/13/2007 7:49 pm ET by VAVince
Go back and read it again.No one is talking about 16 amp breakers. And you need to look at the panel spec. A number of them are specifically designed for tandem breakers.A lot of smaller panels are 12/24. That is 12 slots, but it can have 24 poles by using tandems.Another is 30/40 panels. 30 slots, but 10 of the slots will take tandem breakers giving you 40 poles.And current production panels (don't know for how long) has exclusionary tabs so that the tandems can only be used in certain slots.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Yeah this is definitely a scary thread.
It's pretty easy to overload, muck up and confuse the issues with tandems (and 3-wire shared-neutral circuits). It's obvious from the replies posted here already how confused people get about this stuff. I can't tell you how frequently I come across violations of these 2 topics, and they are IMHO some of the more dangerous mistakes I see. Overloaded panels, overloaded neutrals, unlisted breakers installed.
That said............if you look at the paper glued to the panel door it has spec's and a little line-drawing of the bussbar and breaker configuration. If the panel allows tandems, the drawing will show that. They are represented by lines closer together, usually near the bottom, and are clearly defined by their relationship to the circuit numbers. Each line represents one "pole" or breaker handle so you can count the poles to see what's allowed.
The paper also will tell you what styles of breakers are listed for use in that panel. So, check it out and buy the right stuff.
Ed
Edited 5/13/2007 8:13 pm ET by edlee
Flips,
The code issues are, as said, that you must use the right breaker in the right slot and no more than are allowed by the panel specs.
The only disadvantages I can think of offhand are
1) relatively higher cost for the breakers over their full-sized equivalents
2) potential inability to carry as high a sustained load due to heating problems.
Ed