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Free Shipping Over $99
Free Shipping Over $99
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Siemens B140 Molded Case Circuit Breaker
- 40A
- 1 Pole
- Bolt-On
Siemens
B140
Molded Case Circuit Breaker
Brand
Siemens
SKU
B140
Quantity
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Siemens B140 - 40A 1 Pole Molded Case Circuit Breaker
New
Quantity
Quantity
Siemens B140 - 40A 1 Pole Molded Case Circuit Breaker
New
Quantity
| Brand | Siemens |
|---|---|
| Part Number | B140 |
| Series | BL |
| Amperage | 40A |
| Poles | 1 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Frame Type | B |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1, P2, P3, P4, P5 Panelboards |
| Wire Gauge | 8-6 AWG (Cu), 8-4 AWG (Al) |
| Max Wire | 6 AWG (Cu), 4 AWG (Al) |
| Min Wire | 8 AWG |
| 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 |
|---|---|
| Standards | CSA C22.2 No. 5, UL 489, HACR Rated |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated |
Sold out
Quantity
Siemens B140 - 40A 1 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
| Brand | Siemens |
|---|---|
| Part Number | B140-R |
| Series | BL |
| Amperage | 40A |
| Poles | 1 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Frame Type | B |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1, P2, P3, P4, P5 Panelboards |
| Wire Gauge | 8-6 AWG (Cu), 8-4 AWG (Al) |
| Max Wire | 6 AWG (Cu), 4 AWG (Al) |
| Min Wire | 8 AWG |
| 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 |
|---|---|
| Standards | CSA C22.2 No. 5, UL 489, HACR Rated |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated |
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Description
Built for robust commercial and industrial use, this 40-amp BL series breaker delivers dependable power distribution. The bolt-on design mounts into Siemens P1, P2, P3, P4, and P5 panelboards. It also acts as a substitute for BAB1040, QOB140, and THQB1140 models when cross-referencing compatible systems. Equipped with fixed thermal-magnetic trip units, it ensures precise long-time and instantaneous (LI) protection. The unit is HACR rated and provides a 10kAIC interrupting capacity at 120/240VAC.Specifications
| Brand | Siemens |
|---|---|
| Part Number | B140 |
| Series | BL |
| Amperage | 40A |
| Poles | 1 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Frame Type | B |
|---|---|
| Terminal Type | Lugs |
| For Use With | Siemens P1, P2, P3, P4, P5 Panelboards |
| Wire Gauge | 8-6 AWG (Cu), 8-4 AWG (Al) |
| Max Wire | 6 AWG (Cu), 4 AWG (Al) |
| Min Wire | 8 AWG |
| 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 |
|---|---|
| Standards | CSA C22.2 No. 5, UL 489, HACR Rated |
| Approval | CSA, UL |
| Temp Rating | 40C |
| Construction Features | HACR Rated |
Product FAQs
5 answersWhat panelboards are compatible with the Siemens B140 circuit breaker?
The B140 is a bolt-on breaker designed specifically for Siemens P1, P2, P3, P4, and P5 commercial panelboards. It is not designed for standard plug-on load centers.
Can I install the B140 in a standard residential load center?
No. The B140 is a BL series bolt-on breaker intended for commercial panelboards. Residential load centers typically require plug-on breakers, such as the Siemens QP series.
Is the Siemens B140 breaker HACR rated?
Yes, the B140 is HACR rated. It is approved for use with heating, air conditioning, and refrigeration equipment that requires this specific type of branch circuit protection.
Are there versions of the B140 with a higher interrupting rating?
Yes. The standard B140 has a 10kAIC rating at 120/240VAC. If your application requires a higher interrupting capacity, you can source the B140H for 22kAIC or the B140HH for 65kAIC.
How does the thermal-magnetic trip unit in the B140 operate?
The B140 features a fixed thermal-magnetic trip unit with LI (Long-Time and Instantaneous) functions. The thermal component provides delayed tripping for sustained overloads, while the magnetic component trips instantaneously during short-circuit events.
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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.
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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 35 reviews.
Total 5 star reviews: 34 Total 4 star reviews: 1 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
Reviews Summary
Generated by AI from 66 most recent customer reviews
Last updated 8/15/25
Customers say these circuit breakers meet their specifications and perform as expected. Many reviews highlight the quick delivery times and competitive pricing. Frequent comments address the reliable product quality and ease of installation. The ordering process receives praise for its simplicity, with users noting consistent product availability.
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Rating
35 reviews
- TSTom S.Verified BuyerReviewingSiemens B3100 3 Pole Circuit BreakerI recommend this productRated 5 out of 5 stars8/3/26Superbreakers is our go to!
Great prices, great service and quick delivery.
- MGMaggie G.Verified BuyerReviewingSiemens B250 - 50A 2 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars6/24/26Great Service
Came in great condition and in an incredibly timely manner. Will continue superbreakers for all of my orders in the future!
- DBDonnie B.Verified BuyerReviewingSiemens B115 - 15A 1 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars6/11/26New Breaker
Awesome breaker & Superbreakers is a awesome company!
- BLBrian L.Verified BuyerReviewingSiemens B120 - 20A 1 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars6/4/26Brian
Works great
- JFJoseph F.Verified BuyerReviewingSiemens B120 - 20A 1 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars3/23/26Great value
It was a great value