Last Updated on October 22, 2023 by Kevin Chen
Circuit breakers are integral units in any wiring design. They have an important role to play when it comes to the unexpected events such as current overload or short circuits.
Since there are many different types of circuit breakers, you should always ensure that you get the right one for your application.
Two types that you are likely to end up using include QO and QOB circuit breakers.
These are two types of circuit breakers manufacture by Square D, a subsidiary of Schneider Electric.
Both are circuit breakers that perform the same function: protecting the circuit from overload.
They will trip to cut off current supply in the circuit.
They also tend to be similar in many other ways such as design and structure.
What are they? What is the difference between them and which one should I use?
As the experts in the electronic components industry, we are going to answer all these questions.
Overview of QO circuit breaker
QO breaker image source Home Depot
QO stands for Qwik-Open, this is a type of circuit breaker designed to protect electric circuits from overcurrent and short circuit-just like other circuit breakers in the market.
This breaker features a plug-on design that ensures it perfectly fits into different service panels, such as those that are labeled OEM, NQOM and Speed-D.
QO breakers come in different configurations, a feature that makes them compatible with different types of service panels.
You can choose a single-pole, double-pole or even three-pole QO circuit breaker.
Despite all these variations, most are designed to work with QO service panels.
Features of QO circuit breakers
Let’s look at the key features that characterize the QO circuit breakers from Square D.
-Shunt Trip: This is an accessory that allows the circuit breaker to be opened remotely using a different control circuit. You are likely to find this feature in most commercial QO circuit breakers.
-Visi-Trip: This is a Square D-patented feature and serves as an identity indicator in case your circuit breaker trips. It is ideal when there are numerous circuit breaker in a panel and you want to find one that has tripped easily.
-Common Trip: As we have mentioned, multipolar is one configurations of the QO circuit breakers. The Common Trip feature ensures that all the poles in the breaker trip simultaneously. This enhances the effectiveness of the circuit breaker.
-Plug-on Neutral: This is a unique feature that allows the QO circuit breaker that makes it possible to connect the breaker to the neutral line in the breaker box. You will not need any modification to make such connection.
QOB circuit breaker overview
QOB circuit breaker image source Schneider
QO stands for the Quik Open. The ‘B’ stands for the ‘Bolt-in’ and this is where the whole difference comes. It has a different design and ergonomics. Otherwise, it has the same working principle and operation with the QO circuit breaker.
The bolt-in design means that you will use a bolt or a screw to attach the breaker to the service panel box. The mode makes it possible to install the breaker into the an already-full circuit board.
Just like its nemesis, QOB breakers come in different variations. Some like QOB120 are single-pole circuit breakers while others such as QOB220 are double-pole circuit breakers.
QOB circuit breaker is also characterized by the same features that we have discussed above. These include the Common trip, Visi-trip, Shunt trip and Plug-on neutral features.
QO Breaker vs QOB Breaker: What’s The Difference?
QO and QOB differ in two main areas. These are the installation process and their application areas.
When it comes to the installation, QO circuit breakers are directly installed to the service panelboard like most breakers in the market. You don’t need to do any form of modification or use an accessory to fit the circuit breaker into its rightful position in the panel.
This is slightly different with the QOB. The bolt-in design means that you will have to use a screw and a bolt to attach the circuit breaker into the panelboard. While this may seem to be an extra process, it has an advantage of flexibility. You can install it on any point of the panel board, even when there seems to be no more room for other circuit breakers.
Another difference is on their application areas. QO breakers are mostly used for the residential applications while the QOB breakers are mainly used in the industrial applications.
The flexibility to be installed into any service panel makes the QOB an ideal option for commercial settings, where there are numerous circuits and many electronic machineries.
How do I physically distinguish the two?
You can physically differentiate QOB and QO just by looking at their mounting mechanism. Like most circuit breakers in the market, QO has a tab that is positioned at the center of the breaker. This tab allows you to install the circuit breaker to the service panel directly. During the installation, the tab will click or snap indicating that it has been perfectly installed.
On the other hand, the surface of a QOB circuit breaker provides space for the metal mounting plate through which you can attach a bolt and a screw during the installation process. This plate is positioned at the end of the circuit breaker and has holes for bolt and screws.
Now you know the differences between QO and QOB circuit breakers.
Which one should I buy?
Since the differences seem to be minimal, the final choice will depend on your preferences.
What would you like to achieve from the breaker or what electronic specifications would you like to meet?
From the article, the main difference is in how they are installed into the panelboard.
Once you decide on one, proceed to buy from a reputable electronic components suppliers in China.
This is where ICRFQ comes in. We are a supplier and distributor of QO and QOB circuit breakers in China.
Contact us if you need one or both of these breakers and we will ensure you get them in time.
We can also meet your needs if you want to buy circuit breakers wholesale.
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