Free Shipping Over $99
Free Shipping Over $99
Free Shipping Over $99
Free Shipping Over $99
Siemens BQ2B045 Molded Case Circuit Breaker
- 45A
- 2 Pole
- Bolt-On
Siemens
BQ2B045
Molded Case Circuit Breaker
Brand
Siemens
SKU
BQ2B045
Quantity
Shop with Confidence
Add an extra year of protection in your cart.
Siemens BQ2B045 - 45A 2 Pole Molded Case Circuit Breaker
New
Quantity
Quantity
Siemens BQ2B045 - 45A 2 Pole Molded Case Circuit Breaker
New
Quantity
| Brand | Siemens |
|---|---|
| Part Number | BQ2B045 |
| Series | BQ |
| Amperage | 45A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Frame Type | BQ |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1, P2, P3 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 Thermal, Fixed Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Load Side Lugs |
| Standards | CSA C22.2 No. 5, HACR Rated, UL 489 |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
Sold out
Quantity
Siemens BQ2B045 - 45A 2 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
| Brand | Siemens |
|---|---|
| Part Number | BQ2B045-R |
| Series | BQ |
| Amperage | 45A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Frame Type | BQ |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1, P2, P3 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 Thermal, Fixed Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Load Side Lugs |
| Standards | CSA C22.2 No. 5, HACR Rated, UL 489 |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
Similar Items
50A 2 Pole Molded Case Circuit Breaker
50A 2 Pole Molded Case Circuit Breaker
40A 2 Pole Molded Case Circuit Breaker
Description
Rated for 45 amps at 120/240VAC, this standard interrupting bolt-on breaker delivers essential long-time and instantaneous fault defense. It fastens securely into Siemens P1, P2, and P3 commercial panelboards, establishing a solid mechanical and electrical connection. The HACR-rated design includes Insta-Wire technology to accelerate the wiring process for electrical contractors. This model also functions as a dependable cross-reference alternative for BAB2045 and THQB2145 applications.Specifications
| Brand | Siemens |
|---|---|
| Part Number | BQ2B045 |
| Series | BQ |
| Amperage | 45A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Frame Type | BQ |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1, P2, P3 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 Thermal, Fixed Magnetic |
| Available Options | Shunt Trip, Auxiliary Switch, Alarm Switch, Padlock Attachment |
|---|---|
| Accessories | Load Side Lugs |
| Standards | CSA C22.2 No. 5, HACR Rated, UL 489 |
| Approval | CSA, HACR, UL |
| Temp Rating | 40C |
Product FAQs
6 answersWhich panelboards accept the Siemens BQ2B045 circuit breaker?
This bolt-on breaker is designed for installation in Siemens P1, P2, and P3 panelboards. It requires a bolted connection to the bus and cannot be installed in standard plug-on load centers.
Is the BQ2B045 circuit breaker HACR rated?
Yes, Siemens BQ frame breakers are HACR rated. This allows the 45A breaker to be used for protecting heating, air conditioning, and refrigeration equipment circuits that require this specific UL listing.
Can the Siemens BQ2B045 be reverse fed?
Yes. Siemens BQ frame breakers feature a non-interchangeable trip unit and are suitable for reverse feed applications in accordance with UL 489 guidelines.
How does the Siemens BQ series differ from the BL series?
Both are 1-inch per pole bolt-on breakers, but they utilize different bus attachment tabs. The BQ frame has a centered mounting tab, whereas the BL frame uses a low-tab design that is standard in newer Siemens panelboards. Verify the required tab style for your specific panel interior before installation.
Can I substitute a BQD breaker for a BQ2B045?
No. While they share a similar 1-inch pole width, BQD breakers are designed for higher voltage systems up to 480Y/277VAC and have different mounting configurations. The BQ2B045 is strictly rated for 120/240VAC systems.
Does the BQ2B045 provide arc fault or ground fault protection?
No. This is a standard thermal-magnetic breaker equipped with fixed long-time and instantaneous (LI) trip functions. It does not provide AFCI or GFCI protection.
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 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.
Search
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.