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Video: If a QO load center catalog number cannot be determined, how can you tell if the load center will accept the QOT tandem circuit breakers and where do they mount in the load center?

Published date: 11 November 2019

Installing QOT Tandem Circuit Breakers in QO™ Load Centers

Product Line:
QO Load Centers

Mounting Tandem breakers


NOTE:  NONE of the current Plug-On Neutral(PoN) design load centers will accept the QOT type tandem breakers, they can ONLY use the Old Style QO type tandem breakers. The current QO PoN type load centers will have a suffix 'P' in the catalog number.

1) Not All QO load centers will accept the QOT type tandem breakers.
2) Some load centers are designed to accept the QOT tandem breakers in all spaces. For example, a catalog number of QO12040M200 contains 20 full spaces-40 circuits by using QOT tandems in every pole space.
3) Some are designed to accept QOT breakers only in some of the spaces. For example, a catalog number of QO13040M200 contains 30 full spaces-40 circuits by using QOT tandems in ONLY 10 pole spaces.
4) Some are designed NOT to accept ANY QOT tandem breakers. For example, a catalog number QO140M200, contains 40 full single pole spaces with NO QOT tandem breaker positions. 

The spaces of a QO load center interior that WILL accept QOT tandem circuit breakers can be identified by rectangular 'slots'(of plastic interiors ONLY) in the mounting rails of the interior. These slots accept the mounting cam (or "foot") that is used on the wire terminal end of the QOT breakers. If the mounting rails do NOT have the slots, then a QOT breaker CANNOT be used in that space or load center. The tandem locations will begin at the bottom (or opposite end of the Mains) of the interior and go upward towards the Mains.
These visual are located in the below attached load center instructions that come with each load center.

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