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Square D QOU370-1021 QOU3701021 - 70A 3 Pole Miniature Circuit Breaker
- 70A
- 3 Pole
- Unit Mount
Square D
QOU370-1021
QOU3701021 - 70A 3 Pole Miniature Circuit Breaker
Brand
Square D
SKU
QOU370-1021
Quantity
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Square D QOU3701021 - 70A 3 Pole Miniature Circuit Breaker
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Description
Part of the QOU series, this 70A, three-pole miniature breaker features a factory-installed 120-240V shunt trip for remote disconnects. It delivers reliable thermal-magnetic protection for commercial and industrial systems. Designed for flexibility, the unit mounts onto standard DIN rails or flat surfaces within OEM panels. It includes reversible line and load lugs, accommodating 14-2 AWG wiring. Rated 10 kAIC at 240VAC, it includes a Visi-Trip indicator for fast troubleshooting.Specifications
| Brand | Square D |
|---|---|
| Series | QOU |
| Amperage | 70A |
| Poles | 3 |
| Mounting Style | Unit Mount |
| Voltage | 240VAC, 48VDC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC, 5kA @ 48VDC |
| Frame Type | QOU |
|---|---|
| Terminal Type | Box Lugs |
| For Use With | DIN Rail Systems, OEM Panels, Control Panels, Enclosures |
| Wire Gauge | 14-2 AWG (Al/Cu) |
| Max Wire | 2 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Mounting Feet, Padlock Attachment |
|---|---|
| Accessories | Shunt Trip (Factory Installed), Line and Load Lugs Included |
| Standards | CSA C22.2 No. 5, IEC 60947-2, NEMA AB 1, UL 489 |
| Approval | CSA, HACR, IEC, UL |
| Temp Rating | 40C |
Product FAQs
8 answersWhat does the 1021 suffix mean on the QOU3701021?
The 1021 suffix indicates that this breaker includes a factory-installed 120/240VAC shunt trip. This allows for remote tripping of the breaker in control panels or automated systems.
How does the shunt trip affect the physical footprint of the QOU3701021?
Factory-installed electrical accessories like the shunt trip take up an additional pole space. Since this is a 3-pole breaker, the addition of the shunt trip means it will occupy four pole spaces in your panel or DIN rail setup.
Can I add a shunt trip to a standard QOU370 in the field?
No. Shunt trips for QOU breakers must be factory-installed. If you need remote trip functionality, you must order a breaker with the appropriate suffix, such as the QOU3701021, rather than attempting a field modification.
Is the QOU3701021 compatible with standard Square D QO load centers?
No, QOU series breakers are unit mount devices intended for 35mm DIN rail or surface mounting in control panels and enclosures. They cannot be installed in standard QO plug-on or NQOB bolt-on panelboards.
What wire sizes are accepted by the shunt trip terminals on this breaker?
The shunt trip terminals on the QOU3701021 accept two 14 to 12 AWG copper wires. The hot and neutral wires can be connected to either terminal.
Does the QOU3701021 include a visual trip indicator?
Yes, like other QO and QOU family breakers, this model features a Visi-Trip indicator. When the breaker trips due to an overcurrent condition or via the shunt trip, a red indicator appears in the window to help quickly identify the tripped circuit.
Are the line and load lugs reversible on the QOU3701021?
Yes, QOU breakers feature reversible line and load lugs. This allows for convenient flush or surface mount wiring depending on your enclosure layout and cable routing needs.
Is the QOU3701021 rated for HVAC applications?
Yes, this breaker is HACR rated, making it suitable for use with heating, air conditioning, and refrigeration equipment that requires group motor installations.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 107 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
107 reviews
- VBVictor B.Verified BuyerReviewingSquare D QOU280 - 80A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars10/6/26Square D QOU280
As advertised, works great under normal load conditions. We Recomend this product. Service and shipping was great and easy. Pleasure to deal with.
- 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