brycenesbitt
Senior Member
- Location
- United States
I wanted to comment on an old thread:
Eaton Giving up on Notching CTL Bus Bars?
This is Eaton's current (September 2025) page on the notched stabs. Placed here for archival purposes:
Eaton appears to have given up on notching bus stabs, and somewhat reduced the price of tandem breakers that are compatible
with full (un-notched) bus stabs.
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https://knowledgehub.eaton.com/s/article/What-is-the-difference-between-the-BD-BQ-and-BQC-breakers
Q: What is the difference between the BD, BQ and BQC breakers?
A:
BD – Duplex
BQ – Quadplex (independent trip)
BQC – Quadplex (common trip)
The BD, BQ, and BQC circuit breakers are also known as CTL breakers and have a rejection tab on the bus connection side of the breaker to prevent them from used in certain areas of loadcenter. CTL stands for Circuit Total Limitation.
These breakers are used in BR type CTL loadcenters. A circuit limiting loadcenter has notched bus stab so that only certain number of duplex/quadplex beakers can be installed into them. The BQ quadplex breakers feature the independent trip function where each circuit/pole trips independently of the other. The BQC breakers have a common trip feature where the center and/or outer poles will trip synchronously.
CTL breakers are not compatible with non-CTL (current offering) loadcenters.
The image below shows an example of the notched bus and how a CTL breaker with rejection tab can still be installed on that loadcenter.
For more information and Eaton's current offering of CTL breaker please visit this catalog page.
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In short the more flexible Eaton breakers that go into ANY panel are:
See also Wikipedia:
en.wikipedia.org
Of course you still need to respect panel fill and ampacity limits, regardless.
Eaton Giving up on Notching CTL Bus Bars?
This is Eaton's current (September 2025) page on the notched stabs. Placed here for archival purposes:
Eaton appears to have given up on notching bus stabs, and somewhat reduced the price of tandem breakers that are compatible
with full (un-notched) bus stabs.
=============================================================================
https://knowledgehub.eaton.com/s/article/What-is-the-difference-between-the-BD-BQ-and-BQC-breakers
Q: What is the difference between the BD, BQ and BQC breakers?
A:
BD – Duplex
BQ – Quadplex (independent trip)
BQC – Quadplex (common trip)
The BD, BQ, and BQC circuit breakers are also known as CTL breakers and have a rejection tab on the bus connection side of the breaker to prevent them from used in certain areas of loadcenter. CTL stands for Circuit Total Limitation.
These breakers are used in BR type CTL loadcenters. A circuit limiting loadcenter has notched bus stab so that only certain number of duplex/quadplex beakers can be installed into them. The BQ quadplex breakers feature the independent trip function where each circuit/pole trips independently of the other. The BQC breakers have a common trip feature where the center and/or outer poles will trip synchronously.
CTL breakers are not compatible with non-CTL (current offering) loadcenters.
The image below shows an example of the notched bus and how a CTL breaker with rejection tab can still be installed on that loadcenter.
For more information and Eaton's current offering of CTL breaker please visit this catalog page.
=============================================================================
In short the more flexible Eaton breakers that go into ANY panel are:
| BR | Non-CTL | Various types |
| BRD | Non-CTL | Various types, all BR compatible |
| BRDC | Non-CTL | Double width, two common trip circuits |
See also Wikipedia:
Circuit total limitation - Wikipedia
Of course you still need to respect panel fill and ampacity limits, regardless.
