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Square D QOU345 Miniature Circuit Breaker
- 45A
- 3 Pole
- Unit Mount
Square D
QOU345
Miniature Circuit Breaker
Brand
Square D
SKU
QOU345
Quantity
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Square D QOU345 - 45A 3 Pole Miniature Circuit Breaker
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Description
Built for demanding commercial environments, the Square D QOU345 is a 45A, 3-pole miniature circuit breaker. It provides robust thermal-magnetic protection for a wide range of electrical systems. Designed for versatile installation, this unit-mount breaker fits standard DIN rail systems, OEM panels, and custom enclosures. It includes reversible box lugs for flexible top or bottom feed wiring. Delivering 10 kAIC at 240VAC, this HACR-rated device features a built-in Visi-Trip indicator.Specifications
| Brand | Square D |
|---|---|
| Part Number | QOU345 |
| Series | QOU |
| Amperage | 45A |
| 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 | DIN Rail Systems, OEM Panels, Control Panels, 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 | Visi-Trip Indicator (Built-in) |
| 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, Reversible Feed, Common Trip |
Product FAQs
6 answersHow is the QOU345 circuit breaker mounted in an enclosure?
This unit-mount breaker features built-in slots for installation on a standard 35mm DIN rail. It can also be surface mounted or flush mounted using field-installable mounting brackets.
What wire materials are approved for the box lugs on the QOU345?
The terminals are rated for both aluminum and copper conductors. They accept wire sizes from 14 AWG up to 2 AWG.
Are the line and load connections directional on the QOU345?
No, the slotted box lugs are reversible. You can wire the line and load connections to either side of the breaker for easier routing in tight control panels.
Will the QOU345 fit into a standard Square D QO residential load center?
No. While it shares the QO family name, the QOU series consists of unit-mount breakers for control panels and DIN rail systems. It lacks the plug-on jaw required for standard QO load centers.
Is the QOU345 breaker HACR rated for motor loads?
Yes, it is HACR rated, which allows it to be used for overcurrent protection in heating, air conditioning, and refrigeration equipment.
What is the DC voltage rating for the QOU345?
In addition to its AC ratings, this breaker is UL Listed for 48VDC applications, providing a 5kA interrupting capacity for direct current systems.
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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!