Free Shipping Over $99
Free Shipping Over $99
Free Shipping Over $99
Free Shipping Over $99
Square D QOU140 Miniature Circuit Breaker
- 40A
- 1 Pole
- Unit Mount
Square D
QOU140
Miniature Circuit Breaker
Brand
Square D
SKU
QOU140
Quantity
Shop with Confidence
Add an extra year of protection in your cart.
Square D QOU140 - 40A 1 Pole Miniature Circuit Breaker
New
Quantity
Similar Items
50A 1 Pole Miniature Circuit Breaker
30A 1 Pole Miniature Circuit Breaker
25A 1 Pole Miniature Circuit Breaker
Description
Built for residential, commercial, and industrial applications, the QOU140 delivers reliable overcurrent protection. This 1-pole, 40A miniature circuit breaker is rated for 120/240VAC and 48VDC systems. It installs into DIN rail systems, OEM panels, and control enclosures using a versatile unit mount design. The breaker accepts 14-2 AWG aluminum or copper wire via slotted box lugs. Featuring a 10kAIC rating, this HACR-rated breaker includes reversible lugs and a Visi-Trip indicator.Specifications
| Brand | Square D |
|---|---|
| Part Number | QOU140 |
| Series | QOU |
| Amperage | 40A |
| Poles | 1 |
| Mounting Style | Unit Mount |
| Voltage | 120/240VAC, 48VDC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC, 5kA @ 48VDC |
| Frame Type | QOU |
|---|---|
| Terminal Type | Box Lugs |
| For Use With | DIN Rail Systems, OEM Panels, Enclosures, Control Panels |
| 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 Thermal, Fixed Magnetic |
| Available Options | Mounting Feet, Padlock Attachment, Terminal Shields |
|---|---|
| Accessories | Line and Load Lugs Included |
| Standards | CSA C22.2 No. 5, HACR, IEC 60947-2, UL 489 |
| Approval | CSA, HACR, IEC, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator, Reverse Feed |
Product FAQs
5 answersHow is the Square D QOU140 circuit breaker mounted?
The QOU140 is a unit-mount breaker that can be surface-mounted, flush-mounted, or installed on a standard 35mm DIN rail using a compatible mounting bracket.
Is the QOU140 circuit breaker HACR rated?
Yes, this breaker is HACR (Heating, Air Conditioning, and Refrigeration) and Switching Duty rated, making it suitable for HVAC equipment and control panels.
Can the QOU140 breaker be reverse-fed?
Yes, because it does not have specific Line and Load markings, the QOU140 can be reverse-fed (back-fed). It features reversible slotted box lugs for flexible wiring.
How can I tell if the QOU140 has tripped?
The breaker features Square D's Visi-Trip indicator, which provides a highly visible red signal when the breaker has tripped due to an overcurrent or short circuit.
What accessories are compatible with the QOU140?
Compatible accessories include padlock attachments for lockout/tagout procedures, as well as DIN rail mounting brackets and jumper bars for multi-breaker configurations.
SuperClub
Join free. Get 500 SuperPoints.
Earn points on eligible purchases and redeem them at checkout.
100 SuperPoints = $1 off.
Warranties
Add an extra year of protection
60-Day Warranty
Your purchase includes 60 days of SuperBreakers warranty coverage.
Add a 1-year warranty extension in your cart.
Get a Quote
Don’t see what you’re looking for?
We source obsolete and hard-to-find parts every day.
Shipping
Free Shipping Policy
Parcel shipments with item value over $99 qualify for free economy shipping within the continental US. Please call to confirm special handling instructions. We do not charge a handling fee or require a minimum amount on any order. SuperBreakers does not ship on customer accounts.
Same Day Shipping
We strive to ship out your items the same day the order is placed. In rare circumstances SuperBreakers may reserve up to 5 business days to consolidate orders for complete shipment.
Expedited Shipments
Orders being shipped via Next Day Air, 2 Day Shipping or 3 Day Shipping must be received by 3 PM EST to guarantee same-day shipments. Expedited orders only ship on normal business days. Shipments will NOT be sent out on Saturdays and Sundays.
International Shipping
All International orders require a $1,000 minimum order threshold. Due to the special nature of these shipments, we require that these be placed with a SuperBreakers representative. Additional shipping and instructions will apply. All International Orders are Non-Cancel and Non-Refundable.
Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 110 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.
Search
Rating
110 reviews
- DSDavid S. R.Verified BuyerReviewingSquare D QOU250 - 50A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars11/10/26Perfect upgrade!
Replaced old unreliable fuses on furnace. Works great.
- DSDavid S. R.Verified BuyerReviewingSquare D QOU230 - 30A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars11/10/26Perfect upgrade!
Breaker to replace old unreliable fuses on furnace. Works great.
- MMMichael M.Verified BuyerReviewingSquare D QOU3100 - 100A 3 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars10/13/26Excellent Customer service
We had a new piece of equipment come in that has a higher nameplate rating than was originally conveyed. The lead time from the supply house was outrageous at 10-12 weeks. We ordered it from SuperBreakers and had the equipment running in 3 days. Angel the sales rep. followed up several times first to confirm the order arrived and second that it was the correct
breaker.
- 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