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Square D QOB3151021 Miniature Circuit Breaker
- 15A
- 3 Pole
- Bolt-On
Square D
QOB3151021
Miniature Circuit Breaker
Brand
Square D
SKU
QOB3151021
Quantity
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Square D QOB3151021 - 15A 3 Pole Miniature Circuit Breaker
New
Quantity
Quantity
Square D QOB3151021 - 15A 3 Pole Miniature Circuit Breaker
New
Quantity
| Brand | Square D |
|---|---|
| Part Number | QOB3151021 |
| Series | QOB |
| Amperage | 15A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 120VAC, 240VAC, 120/240VAC, 48VDC |
| Phase | 3 |
| AIC Rating | 10kA @ 120VAC, 10kA @ 240VAC, 10kA @ 120/240VAC, 5kA @ 48VDC |
| Frame Type | QOB |
|---|---|
| Terminal Type | Pressure Plate |
| For Use With | Square D NQ Panelboards, Square D NQOD Panelboards |
| Wire Gauge | 14-8 AWG (Cu/Al) |
| Max Wire | 8 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Auxiliary Switch, Alarm Switch |
|---|---|
| Accessories | Shunt Trip (Factory Installed), Load Side Lugs Included |
| Standards | HACR, UL 489, CSA C22.2 No. 5 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Visual Trip Indicator, HACR Rated |
Sold out
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Square D QOB3151021 - 15A 3 Pole Miniature Circuit Breaker
Re-Certified
Quantity
| Brand | Square D |
|---|---|
| Part Number | QOB3151021-R |
| Series | QOB |
| Amperage | 15A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 120VAC, 240VAC, 120/240VAC, 48VDC |
| Phase | 3 |
| AIC Rating | 10kA @ 120VAC, 10kA @ 240VAC, 10kA @ 120/240VAC, 5kA @ 48VDC |
| Frame Type | QOB |
|---|---|
| Terminal Type | Pressure Plate |
| For Use With | Square D NQ Panelboards, Square D NQOD Panelboards |
| Wire Gauge | 14-8 AWG (Cu/Al) |
| Max Wire | 8 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Auxiliary Switch, Alarm Switch |
|---|---|
| Accessories | Shunt Trip (Factory Installed), Load Side Lugs Included |
| Standards | HACR, UL 489, CSA C22.2 No. 5 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Visual Trip Indicator, HACR Rated |
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Description
Built to accommodate specialized control needs, this 15A miniature circuit breaker incorporates a factory-installed shunt trip. This feature permits remote opening of the circuit via an external voltage signal. The device fastens into Square D NQ and NQOD panelboards using a robust bolt-on configuration that withstands heavy use in commercial applications. Capable of handling 10kA fault currents at 240VAC, the unit also features a Visi-Trip red indicator flag and is fully HACR rated.Specifications
| Brand | Square D |
|---|---|
| Part Number | QOB3151021 |
| Series | QOB |
| Amperage | 15A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 120VAC, 240VAC, 120/240VAC, 48VDC |
| Phase | 3 |
| AIC Rating | 10kA @ 120VAC, 10kA @ 240VAC, 10kA @ 120/240VAC, 5kA @ 48VDC |
| Frame Type | QOB |
|---|---|
| Terminal Type | Pressure Plate |
| For Use With | Square D NQ Panelboards, Square D NQOD Panelboards |
| Wire Gauge | 14-8 AWG (Cu/Al) |
| Max Wire | 8 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Auxiliary Switch, Alarm Switch |
|---|---|
| Accessories | Shunt Trip (Factory Installed), Load Side Lugs Included |
| Standards | HACR, UL 489, CSA C22.2 No. 5 |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | Visual Trip Indicator, HACR Rated |
Product FAQs
7 answersWhat does the 1021 suffix mean on the QOB3151021?
The 1021 suffix indicates that the breaker includes a factory-installed 120/208/240 VAC shunt trip. This accessory allows the breaker to be tripped remotely using an external voltage signal.
How many panel spaces does the QOB3151021 require?
This breaker requires four pole spaces. Although it is a 3-pole breaker, the factory-installed shunt trip accessory occupies one additional pole space in the panelboard.
Can I field-install a shunt trip on a standard QOB315 breaker?
No. Shunt trips for Square D QO and QOB miniature circuit breakers cannot be added in the field. They must be factory-installed, which is why you must order a specific model like the QOB3151021 if your application requires remote tripping.
How do I wire the shunt trip on this breaker?
The shunt trip accessory features its own terminals that accept two 14-12 AWG copper wires. The hot and neutral wires from your 120/208/240 VAC control circuit can be connected to either terminal to enable the remote tripping function.
How can I tell if the QOB3151021 has tripped?
This breaker features the Square D Visi-Trip indicator. When the breaker trips due to an overcurrent, a short circuit, or a remote shunt trip signal, the handle moves to a center position and a highly visible red flag appears in the indicator window.
Is the QOB3151021 HACR rated?
Yes, standard QOB thermal-magnetic circuit breakers, including this model, are HACR rated for use with heating, air conditioning, and refrigeration equipment.
What is the difference between QO and QOB circuit breakers?
QO breakers are plug-on units designed for QO load centers, while QOB breakers like the QOB3151021 feature a bolt-on connection designed specifically for NQ and NQOD panelboards. The bolt-on design provides a more secure connection for commercial and industrial applications.
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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