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Square D QO Breakers

Square D QO Circuit Breakers (Schneider Electric) offer protection and reliability for residential and commercial electrical systems. Built with Visi-Trip indicators, QO breakers provide visual cues when tripped, and feature a bolt-on design to ensure a secure and stable connection within QO load centers and panels. Available in single-pole, double-pole, and various specialty models, they are designed to meet diverse electrical requirements. Compliant with UL standards, QO breakers are a trusted choice for demanding electrical applications. Need help finding products? For 24/7 sales assistance, call 1-650-692-0700.
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Frequently Asked Questions

LiveWire Electrical Supply is your trusted source for hard-to-find electrical supplies, offering a wide selection of circuit breakers, fuses, safety switches, and industrial control products—all ready to ship the same day. With real-time stock and price checks, you can easily find what you need at competitive prices, whether for residential, commercial, or industrial projects. Our experts are available to assist with part identification and technical support, while our expedited shipping options and free UPS Ground shipping on qualifying orders ensure fast delivery. For 24/7 assistance and personalized support, call 1-650-692-0700.

What breakers fit in a Square D QO panel?

Square D QO panels are designed to fit Square D QO circuit breakers. These breakers include single-pole, double-pole, GFCI, AFCI, and dual-function breakers. The QO series breakers feature a Visi-Trip indicator and a unique clip design that ensures secure connections within the panel. While some aftermarket brands may claim compatibility, it is best to use only Square D QO breakers to ensure proper fit, performance, and compliance with safety standards. Always refer to the panel’s labeling and the manufacturer’s guidelines for approved breaker types.

What is the difference between Square D QO and QOB breakers?

The main difference between QO and QOB is in the mounting methods. QO breakers are plug-on circuit breakers designed to snap into place in load centers and panels. This design is suitable for residential and light commercial applications. 

QOB breakers are bolt-on circuit breakers that require a screw to secure them to the bus bars in the panel, providing a more secure and stable installation. This makes QOB breakers ideal for commercial and industrial applications where vibrations or more demanding conditions might be expected. While both QO and QOB breakers offer reliable protection and share similar electrical characteristics, the key difference is the mounting method—plug-on for QO breakers and bolt-on for QOB breakers—tailoring them to different installation environments and requirements.

What is the difference between Square D QO and QOT?

The difference between QO and QOT breakers is in their configuration and application within the electrical panel. QO breakers are standard single-pole and double-pole breakers; QOT breakers are tandem breakers, also known as twin or double-stuff breakers, which allow two independent circuits to be installed in a single breaker slot. This design is useful for adding additional circuits in panels where space is limited. While both QO and QOT breakers are designed for use in Square D QO load centers, QO breakers serve standard circuit protection needs, whereas QOT breakers are for situations requiring additional circuits within limited panel space.

Are any breakers interchangeable with Square D?

Square D panels are designed to work with their specific breakers, such as QO and HomeLine. While some third-party manufacturers may produce breakers that claim to be compatible with Square D panels, it is not recommended to use non-Square D breakers. Interchanging breakers can result in improper fit, poor connection, and potential safety hazards, including overheating and failure to trip during an overload.

For safety and to ensure compliance with electrical codes, it is best to use breakers that are listed and approved for use with Square D panels. Always refer to the panel’s labeling and the manufacturer’s guidelines to verify compatibility. Using the correct breakers ensures proper fit, optimal performance, and adherence to safety standards.

How many tandem breakers are allowed on a QO panel?
The number of tandem breakers allowed on a Square D QO panel depends on its model and configuration. Each QO panel has a limited number of spaces to accommodate tandem breakers, which are noted on the panel’s label or in the manufacturer’s specifications. Typically, the panel's labeling includes a chart or list that specifies the maximum number of tandem breakers it can support. This is often expressed as a total number of breaker spaces with a certain number of those spaces designated for tandem (or twin) breakers. For example, a 20-space panel might allow for up to 10 tandem breakers, effectively providing 30 circuits in a 20-space panel. To determine the number of tandem breakers allowed for a specific QO panel, refer to the panel's documentation or the label inside the panel door. Always follow the manufacturer’s guidelines to ensure safe and compliant installation.

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