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Square D QOU350-1021 QOU3501021 - 50A 3 Pole Miniature Circuit Breaker
- 50A
- 3 Pole
- Unit Mount
Square D
QOU350-1021
QOU3501021 - 50A 3 Pole Miniature Circuit Breaker
Brand
Square D
SKU
QOU350-1021
Quantity
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Square D QOU3501021 - 50A 3 Pole Miniature Circuit Breaker
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Description
Engineered for commercial and industrial applications, the QOU350-1021 provides reliable thermal-magnetic overcurrent protection. This 50A, three-pole miniature breaker features a factory-installed shunt trip accessory, allowing the circuit to be opened from a remote location via a separate voltage source (120/208/240VAC). It installs easily onto DIN rails or flat surfaces using mounting feet. The unit includes Square D's Visi-Trip indicator for clear visual confirmation of a tripped status.Specifications
| Brand | Square D |
|---|---|
| Part Number | QOU350-1021 |
| Series | QOU |
| Amperage | 50A |
| 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 does the -1021 suffix indicate on the Square D QOU350-1021?
The -1021 suffix designates that this circuit breaker includes a factory-installed 120V AC shunt trip accessory, allowing the breaker to be tripped remotely via a control signal.
How is the QOU350-1021 circuit breaker mounted?
This QOU frame breaker is a unit-mount device. It can be surface-mounted, flush-mounted, or installed directly on a standard 35mm DIN rail, making it highly adaptable for OEM panels and control enclosures.
Is the QOU350-1021 a plug-on or feed-thru circuit breaker?
It is a feed-thru circuit breaker. Unlike standard residential breakers that plug onto a busbar, this unit uses slotted box lugs for hardwiring both the line and load connections.
What voltage is required to operate the shunt trip on this breaker?
The factory-installed shunt trip mechanism requires a 120V AC control voltage signal to actuate and remotely open the breaker contacts.
Can the QOU350-1021 be used in DC control circuits?
Yes, in addition to its AC ratings, this thermal-magnetic circuit breaker is rated for use in DC systems up to 48V DC, providing an interrupting capacity of 5 kA.
What types of systems is this unit-mount breaker designed for?
It is engineered for OEM equipment, industrial control panels, and custom enclosures where standard load center busbar mounting is not applicable.
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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!