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Square D QOU3151021 Miniature Circuit Breaker
- 15A
- 3 Pole
- Unit Mount
Square D
QOU3151021
Miniature Circuit Breaker
Brand
Square D
SKU
QOU3151021
Quantity
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Square D QOU3151021 - 15A 3 Pole Miniature Circuit Breaker
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Description
Engineered for commercial and industrial applications, the Square D QOU3151021 provides robust thermal-magnetic protection. This 3-pole, 15A miniature circuit breaker is designed to handle demanding environments. The unit-mount configuration allows for versatile installation, including DIN rail, flush, or surface mounting within OEM control panels. It features reversible box lugs for flexible wiring.Specifications
| Brand | Square D |
|---|---|
| Series | QOU |
| Amperage | 15A |
| Poles | 3 |
| Mounting Style | Unit Mount |
| Voltage | 240VAC, 120/240VAC, 48VDC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC, 10kA @ 120/240VAC, 5kA @ 48VDC |
| Frame Type | QOU |
|---|---|
| Terminal Type | Box Lugs |
| For Use With | OEM Panels, Control Panels, DIN Rail Systems, Enclosures |
| Wire Gauge | 14-2 AWG |
| Max Wire | 2 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Fixed Magnetic |
| Available Options | Mounting Feet, Padlock Attachment |
|---|---|
| Accessories | Shunt Trip (Factory Installed) |
| Standards | CSA C22.2 No. 5, IEC 60947-2, UL 489, HACR Rated |
| Approval | CSA, HACR, IEC, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator, Reverse Feed |
Product FAQs
6 answersWhat is the difference between Square D QOU and QO circuit breakers?
QOU breakers are unit-mount devices designed for DIN rail, surface, or flush mounting in OEM panels and enclosures. QO breakers are plug-on devices built specifically for Square D QO load centers and panelboards.
Can I install the QOU3151021 in a standard Square D QO load center?
No. The QOU3151021 is a unit-mount breaker designed for OEM panels, control panels, and DIN rail systems. It does not have the plug-on mounting required for standard QO load centers.
What does the 1021 suffix mean in the QOU3151021 catalog number?
The 1021 suffix indicates that this breaker includes a factory-installed 120/240VAC shunt trip. This accessory allows the breaker to be tripped remotely by an external signal, which is common in automated control panels.
How is the QOU3151021 mounted in a control panel?
This unit-mount breaker can be snapped directly onto a standard 35mm DIN rail. It can also be surface-mounted or flush-mounted using a compatible 3-pole mounting foot, such as the Square D QOUMF3B.
Are the box lugs on the QOU3151021 reversible?
Yes, the slotted box lugs on QOU series breakers are reversible. This allows for flexible line and load wiring configurations, which is especially useful when routing 14 to 2 AWG wire in tight OEM enclosures.
Does the QOU3151021 feature a tripped status indicator?
Yes, QOU series breakers include the Square D Visi-Trip indicator. A highly visible red flag appears in the indicator window when the breaker trips, allowing electricians to quickly identify faulted circuits in a crowded panel.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 106 reviews.
Reviews Summary
Generated by AI from 99 most recent customer reviews
Last updated 5/14/26
Customers say these circuit breakers function properly and arrive quickly. Many reviews highlight fast shipping, competitive pricing, and reliable product condition upon arrival. Users appreciate the wide selection, including hard-to-find models, and note the breakers work as expected for various applications. Common feedback addresses quick order processing and easy website navigation. Most customers report satisfaction with value and delivery speed, with many indicating they will purchase again.
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Rating
106 reviews
- HLHOMETIGO L.Verified BuyerReviewingSquare D QOU260 - 60A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/7/26Good thing
i recommend this for you
- RGRobert G.Verified BuyerReviewingSquare D QOU340 - 40A 3 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/3/26Circuit breakers
I appreciate the fact that you had these in stock. my Square D distributor does not seem to stock these anymore and it takes a couple weeks to get. your pricing is inline with theirs.
- THTiffany H.Verified BuyerReviewingSquare D QOU115 - 15A 1 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/28/26Will use Super Breakers again
Arrived in a timely manner. Exactly what we needed for a job.
- CSCary S.Verified BuyerReviewingSquare D QOU250 - 50A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/12/26Just what I ordered
Just what I needed for dock pedestal
- MHMark H.Verified BuyerReviewingSquare D QOU250VH - 50A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/11/26Square D QOU250VH - 50A 2 Pole Miniature Circuit Breaker
Was just what I expected!