Piggy-back and thin-line breackers

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infinity

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There is nothing wrong with using listed breakers in a panel according to their listing.

Welcome to the Forum. :)
 

Smart $

Esteemed Member
Location
Ohio
will code allow me to use thin line breakers if so is it a good ting to do?:?
Welcome :thumbsup:

I think the non-slang term is tandem breakers.

You can use them as long as they are applied within the listing of the panelboard and of course all other aspects of the installation are Code compliant.

I find them advantageous at times. Being a good or bad thing is rather moot as long as we have no fires or personal tragedies as a result.
 

GoldDigger

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I have heard them called tandem, Piggy back (Sq. D), & twins.

To me tandem has always been associated with a breaker combo that has two handles on a line running outward from the center of the panel, rather than duplex/twin breakers (one stab) or quad breakers (two stabs) that have their handles lined up side by side at the same distance from the center of the panel.
Piggy back brings the same image to mind as tandem.
 

John120/240

Senior Member
Location
Olathe, Kansas
Tandem breakers can be a life saver when you have a already full panel. GE & SQ D both utilize features on their breakers that limit where in the panel you can install them. SQ D also has a selection of tandem breakers without the "hook".
 

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goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
As has been mentioned, as long as the panel accepts tandem (twin or piggy-backed) breakers you can use them. What you have to be careful with is if you're doing new work, many of the circuits may have to be arc fault in which case you won't be able to use tandems.
 

kwired

Electron manager
Location
NE Nebraska
will code allow me to use thin line breakers if so is it a good ting to do?:?
Ever since the development of class CTL breakers 30 to 40 years ago you can not plug a class CTL breaker in a slot not designed to accept it - without modifying the breaker to defeat the rejection feature built into it. There are however still non-CTL breakers out there that will plug into any slot in the panel - but at very least by doing so you are violating listing instructions unless you are using it as a replacement for a previously allowed non CTL assembly.


Though there are some others out there that are similar - Thin Line is primarily General Electric version of "tandem" breakers.

They are slightly different from many other breaker series in that the bus needs to be designed to allow them to plug on. If bus slot is not designed to accept them you will not use these "thin line" breakers at all in that particular slot. Many other "tandems" have rejection feature in the "foot" and all you need to do is modify the foot or foot rail to get them to fit the panel, but GE's bus design with the rejection feature in the bus makes it very difficult to modify and actually make it work for you.
 

PetrosA

Senior Member
Tandem breakers can be a life saver when you have a already full panel. GE & SQ D both utilize features on their breakers that limit where in the panel you can install them. SQ D also has a selection of tandem breakers without the "hook".

To me the first two images are twin breakers, the third shows a tandem breaker.
 

kwired

Electron manager
Location
NE Nebraska
To me the first two images are twin breakers, the third shows a tandem breaker.

The first and last images are both QO series, but the last image is an older version. Square D has named both of them "tandem" type breakers in catalogs and application data on panel labels as well.

I don't know off hand what Eaton/Cutler Hammer addresses their version as.
 

PetrosA

Senior Member
The first and last images are both QO series, but the last image is an older version. Square D has named both of them "tandem" type breakers in catalogs and application data on panel labels as well.

I don't know off hand what Eaton/Cutler Hammer addresses their version as.

Eaton C/H designates them as twins. I've noticed that counter guys at supply houses that distribute Square D tend to give me blank stares when I ask for a twin breaker. I guess that's the effect of training :) I think Siemens also uses "twin" but I'm not sure about the GE type that have that form factor but can actually hook onto both legs and be used as a 240V breaker in certain panels.
 

kwired

Electron manager
Location
NE Nebraska
Eaton C/H designates them as twins. I've noticed that counter guys at supply houses that distribute Square D tend to give me blank stares when I ask for a twin breaker. I guess that's the effect of training :) I think Siemens also uses "twin" but I'm not sure about the GE type that have that form factor but can actually hook onto both legs and be used as a 240V breaker in certain panels.

I seem to recall GE addressing them as 1/2 inch and 1 inch wide breakers and not so much as twins or tandems.
 

PetrosA

Senior Member
I seem to recall GE addressing them as 1/2 inch and 1 inch wide breakers and not so much as twins or tandems.

I think you're right and I was confused. I don't see many GE panels, but now I remember that they make 1" two-pole breakers for that series. That series always throws me off because you can use 1/2" single poles, 1" single poles, 1" double poles and 2" double poles. Goofy.
 

kwired

Electron manager
Location
NE Nebraska
I think you're right and I was confused. I don't see many GE panels, but now I remember that they make 1" two-pole breakers for that series. That series always throws me off because you can use 1/2" single poles, 1" single poles, 1" double poles and 2" double poles. Goofy.

But you can't use those 1/2 sized units in just any space in any panel - the bus has to be designed to accept it or you will not get a connection to the bus even if you find some way to jam it into the space.
 
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