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Square D QO145 Miniature Circuit Breaker
- 45A
- 1 Pole
- Plug-On
Square D
QO145
Miniature Circuit Breaker
Brand
Square D
SKU
QO145
Quantity
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Square D QO145 - 45A 1 Pole Miniature Circuit Breaker
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Description
Manufactured for dependable power distribution, this 45A miniature breaker utilizes a proven thermal-magnetic trip unit to prevent overloads and short circuits. The highly visible red Visi-Trip flag alerts users instantly when the circuit trips, reducing troubleshooting time. It easily installs into any standard QO load center, as well as commercial NQ and NQOD panelboards. The plug-on connection ensures a tight, secure fit. It is HACR rated for use with heating and cooling equipment.Specifications
| Brand | Square D |
|---|---|
| Part Number | QO145-R |
| Series | QO |
| Amperage | 45A |
| Poles | 1 |
| Mounting Style | Plug-On |
| Voltage | 120/240VAC, 48VDC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC, 5kA @ 48VDC |
| Frame Type | QO |
|---|---|
| Terminal Type | Box Lugs |
| For Use With | QO Load Centers, NQ Panelboards, NQOD Panelboards |
| Wire Gauge | 8-2 AWG (Al/Cu) |
| Max Wire | 2 AWG |
| Min Wire | 8 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch, Padlock Attachment |
|---|---|
| Standards | CSA C22.2 No. 5, UL 489, HACR |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated, Visual Trip Indicator |
Product FAQs
6 answersWhich panelboards and load centers are compatible with the QO145?
This breaker installs in Square D QO load centers, as well as NQ and NQOD panelboards. It is not compatible with Homeline (HOM) load centers.
Can the QO145 be installed in a bolt-on panelboard?
No, this is a plug-on breaker. For bolt-on applications in NQ or NQOD panelboards, you must use the QOB equivalent, catalog number QOB145.
Does the QO145 include a tripped breaker indicator?
Yes, standard QO breakers feature the Visi-Trip indicator. A highly visible red flag appears in the window when the breaker has tripped, allowing for quick fault identification.
Is the QO145 HACR rated?
Yes, this breaker is HACR rated, making it suitable for use with heating, air conditioning, and refrigeration equipment that requires this specific rating.
Does this breaker require a plug-on neutral panel?
No, the QO145 is a standard thermal magnetic breaker, not a GFCI or AFCI breaker. It does not require a neutral connection to the breaker itself and can be installed in both standard and plug-on neutral panels.
Will this breaker fit in a tandem or space-saver slot?
No, the QO145 is a standard full-size, single-pole breaker that requires one full 0.75-inch space in the panel. Square D does not manufacture 45A tandem breakers.
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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.
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Reviews
Review summary
Customers rate this product 4.9 out of 5 based on 285 reviews.
Reviews Summary
Generated by AI from 100 most recent customer reviews
Last updated 6/13/26
Customers say these circuit breakers arrive quickly and work as described. Fast shipping and competitive pricing are frequently mentioned, with many noting same-day or next-day delivery. Users appreciate the wide inventory, particularly for hard-to-find older-style models unavailable locally. The products function reliably and arrive in good condition. Most customers report straightforward ordering and positive interactions. However, some experienced delivery delays or received incorrect items requiring reordering. A few noted concerns about condition upon arrival or customer service responsiveness.
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Rating
285 reviews
- GCGerard C.Verified BuyerReviewingSquare D QO130GFI - 30A GFCI Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/21/26Great !
I could not find the breaker in hardwood stores. Superbreakers took car of it in a week.
- RHRoy H.Verified BuyerReviewingSquare D QO280 - 80A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/17/26Square D QO280 - 80A 2 Pole Miniature Circuit Breaker
Exactly as described
- KWKevin W.Verified BuyerReviewingSquare D QO120 - 20A 1 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/15/26Great Price
Brand spanking new!
- CEchristopher e.Verified BuyerReviewingSquare D QO115PDF - 15A Dual Function Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/11/26My breakers
Had a hard time locating these breakers locally, when I did find 1 they wanted to charge me triple what superbreakers charged. Items delivered exactly when they said they would, were exactly what I ordered. Appreciated the ease of ordering, definitely my go to from this point on
- JCJerry C.Verified BuyerReviewingSquare D QO250 - 50A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/8/26Great quality
No issues