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Square D QOB240GFI GFCI Miniature Circuit Breaker
- 40A
- 2 Pole
- Bolt-On
Square D
QOB240GFI
GFCI Miniature Circuit Breaker
Brand
Square D
SKU
QOB240GFI
Quantity
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Square D QOB240GFI - 40A GFCI Miniature Circuit Breaker
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Description
Engineered for commercial and industrial applications, this 40A miniature breaker delivers reliable ground fault protection. It mounts into Square D NQ and NQOD panelboards using a secure bolt-on connection. Featuring Visi-Trip technology for quick fault identification, the unit provides a 10kA interrupting rating and includes a pigtail neutral to meet NEC requirements for wet or damp locations.Specifications
| Brand | Square D |
|---|---|
| Series | QOB |
| Amperage | 40A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Frame Type | QOB |
|---|---|
| Terminal Type | Box Lugs |
| For Use With | NQ Panelboards, NQOD Panelboards |
| Wire Gauge | 8-2 AWG (Al/Cu) |
| Max Wire | 2 AWG |
| Min Wire | 8 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LIG |
| Trip Function | Long-Time, Instantaneous, Ground Fault |
| Trip Adjustability | Fixed |
| Special Classification | GFCI |
|---|---|
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch, Padlock Attachment |
| Accessories | Pigtail Neutral |
| Standards | CSA C22.2 No. 144, UL 489, UL 943 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Visual Trip Indicator |
Product FAQs
9 answersCan I install the QOB240GFI in a standard QO load center?
No. The QOB240GFI features a bolt-on connection designed specifically for Square D NQ and NQOD panelboards. Standard residential QO load centers require plug-on circuit breakers.
How many panel spaces does the QOB240GFI require?
This 2-pole ground-fault circuit breaker requires two adjacent panel spaces in your NQ or NQOD panelboard.
Where does the pigtail wire on this breaker connect during installation?
The coiled white pigtail wire must be connected directly to the neutral bar of the panelboard. This connection is required to power the internal ground-fault detection circuitry.
What is the ground-fault trip sensitivity of this breaker?
The QOB240GFI provides Class A ground-fault protection. This means it is designed to trip when it detects a ground-fault leakage current between 4 and 6 milliamperes (mA).
Does the QOB240GFI provide arc-fault protection?
No. This model is strictly a Ground-Fault Circuit Interrupter (GFCI) and does not detect arc faults. If your application requires both GFCI and AFCI protection, a dual-function circuit breaker is necessary.
What is the difference between the QOB240GFI and the QO240GFI?
The QOB240GFI is a bolt-on circuit breaker designed for commercial NQ or NQOD panelboards. The QO240GFI uses a plug-on mounting mechanism for residential QO load centers. Their electrical ratings and ground-fault protection capabilities are identical.
Can I use this breaker on a 240V circuit that does not require a load neutral?
Yes. For 240V straight loads that do not use a neutral wire, connect the two hot conductors to the breaker terminals and leave the load neutral terminal empty. The breaker's white pigtail wire must still be connected to the panel neutral bar for the GFCI electronics to function.
What does the 10kAIC interrupting rating signify for this breaker?
The 10kAIC rating indicates that the breaker can safely interrupt a maximum short-circuit fault current of 10,000 amps at 120/240VAC without sustaining mechanical or electrical failure.
Can this bolt-on breaker be modified to fit a plug-on load center?
No. The QOB bolt-on mounting bracket is permanently integrated into the breaker frame and cannot be removed or converted. You must purchase the QO240GFI if a plug-on connection is required.
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Reviews
Review summary
Customers rate this product 4.9 out of 5 based on 205 reviews.
Reviews Summary
Generated by AI from 100 most recent customer reviews
Last updated 3/11/26
Customers say these electrical breakers arrive exactly as ordered and work perfectly for their intended applications. They consistently praise the competitive pricing, which many report is significantly lower than local suppliers. Fast shipping and prompt delivery are frequently highlighted, with many receiving orders within days or even next-day delivery for urgent needs. The breakers arrive well-packaged and in excellent condition. Many reviews emphasize the company's extensive inventory availability, particularly for hard-to-find breakers. One customer experienced difficulty with order cancellation and was charged a restocking fee, which caused dissatisfaction.
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Rating
205 reviews
- BLBOOSTIX L.Verified BuyerReviewingSquare D QOB220 - 20A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/17/26QOB220
That's nice breakers!
- PHPaul H.Verified BuyerReviewingSquare D QOB330 - 30A 3 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/5/26Quick shipping and delivery
Shipped and delivered on time for installation at one of our projects. Thank you!
- RMRick M.Verified BuyerReviewingSquare D QOB220 - 20A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/3/26Project Mgr
Just what I needed.
- DHDoug H.Verified BuyerReviewingSquare D QOB220 - 20A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/3/26Square D QOB breakers
As always, our order arrived timely, and accurate. You can’t beat their prices that’s why we have used this company for years.
- RKRyan K.Verified BuyerReviewingSquare D QOB230VH - 30A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars7/1/26Awesome
Worked great