Tandem circuit breakers

[jeff48356]

I see that Home Depot sells two different kinds of tandem breakers for Siemens panels. They have the basic one (Type QT) for $9.41 which fits into panels designed to accept tandem breakers. However, they also have another kind (Type QT-NCL) for $23.94 that works in panels that do not inherently accept tandems. Square-D does not make such a breaker for their Homeline panels, however?

But in either case, what's the difference between simply breaking off part of the plastic that prevents the breaker from fitting into the standard bus bar, versus spending the extra $14 for the NCL type that works without modification? How is the latter any safer than the former?

 

[texie]

I see that Home Depot sells two different kinds of tandem breakers for Siemens panels. They have the basic one (Type QT) for $9.41 which fits into panels designed to accept tandem breakers. However, they also have another kind (Type QT-NCL) for $23.94 that works in panels that do not inherently accept tandems. Square-D does not make such a breaker for their Homeline panels, however?

But in either case, what's the difference between simply breaking off part of the plastic that prevents the breaker from fitting into the standard bus bar, versus spending the extra $14 for the NCL type that works without modification? How is the latter any safer than the former?

Tandem breakers today are marked "CTL" and are designed so they only fit in certain places in an approved panel in order to limit their installation in a UL compliant manner.
Non CTL breakers are sold and marked "for replacement only" and will fit in any spot.
Can't remember if they make non CTL Homeline breakers but they do have non CTL QO breakers.

 

[jim dungar]

Can't remember if they make non CTL Homeline breakers but they do have non CTL QO breakers.

IIRC
The HomeLine panel was designed and built after the CTL rating/requirement (roughly the early 60's) went into effect and all HOM panels are rated for tandems in all slots, therefore there was no need to design and UL List a non-CTL HOM breaker for replacement purposes.

When I started in the trade we called non-CTL breakers 'cheaters'.

 

[curt swartz]

Homeline was introduced in the late 80's. The CTL requirement was already in existence. Since there were no Homeline loadcenters made prior to the CTL requirement there is no reason for them to make a non CTL breaker.

Edit....I got distracted while typing so didn't post before Jim posted the same info.

 

[goldstar]

But in either case, what's the difference between simply breaking off part of the plastic that prevents the breaker from fitting into the standard bus bar, versus spending the extra $14 for the NCL type that works without modification? How is the latter any safer than the former?

First off, I don't think you can just break off the plastic part and have the breaker fit onto the bus. Many of these breakers have a small clip on the jaw so you would have to also remove that in order for the breaker to fit properly. I understand if you had to do that in a pinch to get a circuit working temporarily but I would make it a point to get the correct one and go back and change it out. Besides, once you modify the breaker you void any UL listing and/or warranties not to mention the liability that comes with any type of hazard that may arise associated with the modification.

I'm not going to say I've never done it but I just want to warn you of the liability.