1/2 Inch Or 1: Residentail Circuit Breakers ?


Old 04-20-08, 08:06 AM
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1/2 Inch Or 1: Residentail Circuit Breakers ?


Another question, please, regarding residential Service boxes.

I see that circuit breakers are offered in 1/2 inch and 1 inch sizes.

Obviously, I think, assuming one doesn't exceed the main breaker capacity, it is possible to have more (independent) branch circuits utilizing the 1/2 inch variety.

So, my question is: why hasn't the industry standardized on (just) the 1/2 inch size. ?

Seems like they would fulfill most every need.
Why use the 1 inch at all ?

Are they as reliable, or safe, as the 1 inch types ?

What am I missing, please ?

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Old 04-20-08, 09:45 AM
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Skinnies, tandems, piggybacks, cheaters,.....are half the size of a standard breaker. this allows 2 circuits to occupy the same breaker slot.

Problem is, they only provide for a 120 volt circuit, There is no "Common Trip" so you wouldnt be able to take advantage of 240 volt applications.
Many panel Manufacturers do not approve these for use in specific panels. Of those that do, some will limit their placement to certain slots.

Just as an example of a breaker panel....QO-6-12 -100s.

It is a square D panel, 6 Spaces, will utilize 12 circuits...

Many will be labeled as 6-6 or 20-20. these will not accept the cheaters.

Unless absolutely necessary, they are more trouble than they are worth.
Old 04-20-08, 12:33 PM
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Not all panels have 1" full size breakers. Stating 1" and 1/2 " means not a lot unless you specify the panel brand. The FPE I have use 1/2" breakers as the normal size.
Old 04-20-08, 01:37 PM
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With AFCI and GFCI, you need the full space for these breakers. If you are looking to purchase a new panel, buy it based on how many full sized spaces it has.

Tandems are useful if the panel is full and you need to add another circuit (as I have done recently) but otherwise, I wouldn't plan to use them.

Finally, you can use what I believe is a "quad" breaker, which will give you a 240v circuit and 2 120v circuits, while taking up 2 regular slots in the panel.

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