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QO vs QOB Breaker: Differences and Comparison

Written by Edwin Jones / Fact checked by Andrew Wright


Establishing a proper wiring diagram in your property typically demands the use of the correct circuit breakers. Now you’re wondering about the differences and similarities between a QO vs QOB breaker and whether they’re interchangeable.

Both of these types offer protection against overloads and other issues that may harm connected electronics. Although they function similarly, they have dissimilar mounting structures.

Continue reading to gain additional insight into QO and QOB breakers. By the end of this post, you might be one step closer to finalizing your purchasing decision and installing the correct breaker for your load center.

Comparing QOB vs QO Breakers


What Is A QO Breaker?

QO stands for Qwik-Open, and it’s a circuit breaker known to provide overcurrent, short circuit, and other fault protection. It also has a plug-on design that fits different service panel types, such as those labeled NQ, NQOD, OEM, and Speed-D. 

What Is A QOB Circuit Breaker?


The “B” in QOB meaning is bolt-on, which means it has a different design and layout from QO circuit breakers. Although QOB breakers have a similar function as their QO counterparts, they suit different panels. QOB models, for instance, should go in NQO and NQOD load centers only.

QOB circuit breakers also come in different variations. For instance, the QOB120 is a single-pole option, while the QOB220 is a double-pole model. 

Pros And Cons/Differences

Both QO and QOB share the most advantages and shortcomings. In particular, these breakers can protect electronics from problems resulting from overcurrents. But perhaps the main difference between these two circuit breakers is the mounting style.

The plug-on nature of QO breakers might make them susceptible to shaking and other unwanted movements.

On the other hand, QOB breakers are often more secure than QO circuit breakers due to their bolt-on design. This disparity also makes QOB models more suitable for commercial or industrial applications.

Related: QO Vs QOT Breaker – Pros & Cons

Frequently Asked Questions

Will A QOB Breaker Fit In A QO Panel?

A QOB circuit breaker generally won’t fit in a QO service panel, unless the panel in question is an NQOD type. Forcing the wrong breaker into a load center can render your warranty invalid.

Can You Use QOB Breakers In A QO Load Center?

QO load centers will only accept QO branch circuit breakers with plug-on designs. So a QOB tandem breaker or QOB GFCI breaker will only go in load centers that support its mounting design.

What Breaker Is Compatible With QO?

Circuit breakers that can fit in a QO load center include:

  • QO
  • QO-H
  • QO-VH
  • QO-EPE
  • QO-SWN
  • QO-K

Are Telemecanique Breakers The Same As Schneider Breakers?

Telemecanique is a brand owned by Schneider. The company name Telemecanique began in 1924, which later turned into Schneider Electric in 2009.

But take note that a Telemecanique breaker may not be the same as a circuit breaker from Schneider. As with buying relatively any circuit breaker on the market, it’s best to check if the unit you’re buying will fit your service panel. 

Are There DC Circuit Breakers?

DC circuit breakers exist, and they function to protect connected electronics from issues brought by arcs. Keep in mind that DC breakers work with electronic devices using direct currents, not alternating ones.

Still, it’s possible to find dual-current breakers on the market. For example, you may purchase and install a Schneider Electric DC circuit breaker that you can also use in AC circuits. Some QO and QOB breakers are under this category as well.

Is A Circuit Breaker Schneider Electric Worth It?


Schneider Electric is an established company known by many for provides quality products and services to its customers in the electricity niche. Among its different offerings, its circuit breakers are favorites among customers due to their reliability.

What is a Square D Motorized Circuit Breaker?

First, it’s important to take note of how a motor circuit breaker works. As its name implies, this type of breaker has a motor for remote functions, particularly for overload protection.

Certain Square D circuit breakers have these motors. These modules will open or close the breakers’ current contacts, protecting connected devices from electrical surges.


Now that you know about the comparisons between QO vs QOB breaker, you may have a better idea of which circuit breaker to purchase for your property’s load center.

Remember, these circuit breakers have different mounting requirements. Keep in mind that you shouldn’t install an incorrectly fitting breaker into a breaker box. Otherwise, the circuitry will be at risk of encountering problems.

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