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Siemens BQ3B045 Molded Case Circuit Breaker
- 45A
- 3 Pole
- Bolt-On
Siemens
BQ3B045
Molded Case Circuit Breaker
Brand
Siemens
SKU
BQ3B045
Quantity
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Siemens BQ3B045 - 45A 3 Pole Molded Case Circuit Breaker
New
Quantity
Quantity
Siemens BQ3B045 - 45A 3 Pole Molded Case Circuit Breaker
New
Quantity
| Brand | Siemens |
|---|---|
| Part Number | BQ3B045 |
| Series | BQ |
| Amperage | 45A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC |
| Frame Type | BQ |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1 Panelboards, ITE Panelboards |
| Wire Gauge | 8-1 AWG (Cu), 6-1/0 AWG (Al) |
| Max Wire | 1 AWG (Cu), 1/0 AWG (Al) |
| Min Wire | 8 AWG (Cu), 6 AWG (Al) |
| 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 |
|---|---|
| Accessories | Load Side Lugs |
| Standards | CSA C22.2 No. 5, UL 489 |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
Sold out
Quantity
Siemens BQ3B045 - 45A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
| Brand | Siemens |
|---|---|
| Part Number | BQ3B045-R |
| Series | BQ |
| Amperage | 45A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC |
| Frame Type | BQ |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1 Panelboards, ITE Panelboards |
| Wire Gauge | 8-1 AWG (Cu), 6-1/0 AWG (Al) |
| Max Wire | 1 AWG (Cu), 1/0 AWG (Al) |
| Min Wire | 8 AWG (Cu), 6 AWG (Al) |
| 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 |
|---|---|
| Accessories | Load Side Lugs |
| Standards | CSA C22.2 No. 5, UL 489 |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
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Description
Utilizing proven thermal-magnetic technology, this 45-amp circuit breaker safeguards commercial power systems. It delivers consistent response times to clear electrical faults safely. Engineered with a bolt-on configuration, it installs firmly into Siemens P1 and older ITE panelboards. It serves as an excellent replacement for existing BAB3045 or QOB345 breakers. Operating at 240VAC with a 10kAIC capacity, it handles standard loads and is HACR certified for HVAC equipment.Specifications
| Brand | Siemens |
|---|---|
| Part Number | BQ3B045 |
| Series | BQ |
| Amperage | 45A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC |
| Frame Type | BQ |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1 Panelboards, ITE Panelboards |
| Wire Gauge | 8-1 AWG (Cu), 6-1/0 AWG (Al) |
| Max Wire | 1 AWG (Cu), 1/0 AWG (Al) |
| Min Wire | 8 AWG (Cu), 6 AWG (Al) |
| 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 |
|---|---|
| Accessories | Load Side Lugs |
| Standards | CSA C22.2 No. 5, UL 489 |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
Product FAQs
7 answersWhich panelboards are compatible with the Siemens BQ3B045?
This bolt-on circuit breaker is designed for installation in Siemens P1 panelboards and legacy ITE panelboards. It is not compatible with load centers that require plug-on connections.
Is the BQ3B045 suitable for HVAC equipment?
Yes, this breaker is HACR rated. It is certified for use with heating, air conditioning, and refrigeration equipment that involves motor driven loads.
Does the BQ3B045 include GFCI or AFCI protection?
No. This is a standard thermal magnetic circuit breaker designed for overcurrent and short circuit protection. It does not feature ground fault or arc fault interrupting technology.
How is this breaker secured to the panelboard?
The BQ3B045 uses a bolt-on mounting configuration. It bolts directly to the panel bus bar to ensure a secure mechanical and electrical connection, reducing the risk of hot spots in commercial applications.
Can I use this breaker to replace older ITE components?
Yes. Siemens acquired ITE, and the BQ series serves as a direct replacement for legacy ITE bolt-on breakers with matching specifications.
Can I install the BQ3B045 in another brand of panelboard?
No. While it may share similar dimensions with other 45 amp bolt-on breakers, it is specifically engineered and UL listed only for compatible Siemens and ITE enclosures. Using it in non-specified panels can lead to poor bus bar contact and overheating.
Are the trip settings adjustable on the BQ3B045?
No. The thermal magnetic trip unit features fixed long time and instantaneous trip functions. The settings cannot be adjusted in the field.
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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 73 reviews.
Reviews Summary
Generated by AI from 67 most recent customer reviews
Last updated 6/3/26
Customers say these breakers arrive quickly and fit perfectly for their electrical needs. Fast shipping and competitive pricing are frequently mentioned, with many users appreciating the availability of hard-to-find and older-style breakers. The products are well-packaged and arrive in good condition. Most customers report successful installations and reliable performance. A few note missing items from orders or concerns about product condition, though the majority express satisfaction with their purchases and indicate they would order again.
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Rating
73 reviews
- HSHector S.Verified BuyerReviewingSiemens BQ3B100H - 100A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars9/27/26Perfect replacement
Fit perfectly and good price
- AFAnthony F.Verified BuyerReviewingSiemens BQ2B020 - 20A 2 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars9/25/26works as expected
works as expected
- MSMike S.Verified BuyerReviewingEaton / Cutler-Hammer BQ250250 - 50/50A Quadplex Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars8/12/26Electrical company
Breaker worked awesome thank you very much
- PEPhilip E.Verified BuyerReviewingSiemens BQ3B020 - 20A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars8/10/26Siemens BQ3B020
The breaker arrived as described and on time. It works as expected. I will order from SuperBreakers again in the future without hesitation.
- PLPaul L.Verified BuyerReviewingSiemens BQ1B020 - 20A 1 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars7/23/26Breaker
Quick shipping. Exact fit.