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Square D QOB350EPD GFEP Miniature Circuit Breaker
- 50A
- 3 Pole
- Bolt-On
Square D
QOB350EPD
GFEP Miniature Circuit Breaker
Brand
Square D
SKU
QOB350EPD
Quantity
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Square D QOB350EPD - 50A GFEP Miniature Circuit Breaker
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Description
Providing robust 30mA ground fault detection, this 50A three-pole breaker is optimized for heavy-duty commercial equipment protection. It integrates seamlessly into Square D NQ and NQOD panelboards, utilizing a secure bolt-on mechanism that eliminates the risk of arcing from loose connections. The unit delivers a 10kAIC rating at 240VAC and includes the highly visible Visi-Trip indicator, allowing electricians to instantly spot tripped circuits without opening the panel deadfront.Specifications
| Brand | Square D |
|---|---|
| Part Number | QOB350EPD |
| Series | QOB |
| Amperage | 50A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC |
| Terminal Type | Box Lugs |
|---|---|
| For Use With | Square D NQ Panelboards, Square D NQOD Panelboards |
| Wire Gauge | 14-6 AWG (Cu), 12-4 AWG (Al) |
| Max Wire | 4 AWG (Al), 6 AWG (Cu) |
| Min Wire | 12 AWG (Al), 14 AWG (Cu) |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LIG |
| Trip Function | Long-Time, Instantaneous, Ground Fault |
| Trip Adjustability | Fixed |
| Special Classification | GFEP |
|---|---|
| Available Options | Padlock Attachment |
| Accessories | Load Side Lugs Included |
| Standards | HACR, UL 489, CSA C22.2 No. 5 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator, Common Trip |
Product FAQs
6 answersWhich panelboards are compatible with the QOB350EPD breaker?
This bolt-on circuit breaker is designed exclusively for use in Square D NQ and NQOD series commercial panelboards. It cannot be installed in standard QO residential load centers, which require plug-on breakers.
What is the difference between an EPD breaker and a standard GFCI breaker?
An EPD (Equipment Protection Device) breaker, like the QOB350EPD, features a 30mA ground fault trip threshold designed to protect machinery from damage. A standard GFCI (Class A) breaker has a highly sensitive 5mA threshold for personnel protection. The 30mA limit prevents nuisance tripping on equipment with natural electrical leakage, such as heat trace cables or large motors.
How does the QOB350EPD connect to the panel neutral?
This breaker utilizes a pigtail neutral connection. The attached coiled white wire must be terminated directly to the panelboard neutral bus to power the internal ground fault sensing electronics.
What does the LIG trip function on this breaker indicate?
LIG stands for Long-Time, Instantaneous, and Ground-Fault. This indicates the thermal-magnetic breaker provides delayed tripping for mild overloads, immediate tripping for severe short circuits, and specialized 30mA protection against leakage currents to ground.
Does the QOB350EPD feature a Visi-Trip indicator?
Yes. This breaker includes the Square D Visi-Trip indicator. When the breaker trips due to an overcurrent or ground fault event, a highly visible red flag appears in the handle window, allowing electricians to quickly identify the tripped circuit.
Is there a plug-on version of this breaker available?
Yes. If you need this exact 50A, 3-pole, 30mA equipment protection breaker for a standard QO load center, you will need the plug-on version, catalog number QO350EPD.
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Reviews
Review summary
Customers rate this product 4.9 out of 5 based on 206 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
206 reviews
- KHKristopher H.Verified BuyerReviewingSquare D QOB120GFI - 20A GFCI Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/28/26Great Price!
Great price. Fast delivery. My local electric distributor wanted double for the same breaker, so it was a no brainer to order this one. Ordered another one since with the same great service.
- 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.