Skip to main content
Expedited shipping available at checkout

Siemens BQ1B040 Molded Case Circuit Breaker

  • 40A
  • 1 Pole
  • Bolt-On
Siemens BQ1B040
Molded Case Circuit Breaker
Brand Siemens
SKU BQ1B040
Select Item Condition
Earn 16 SuperPoints
  • 40A
  • 1 Pole
  • Bolt-On

Quantity

Bulk Pricing
Send your parts list for a volume quote.
Siemens BQ1B040 - 40A 1 Pole Molded Case Circuit Breaker

Siemens BQ1B040 - 40A 1 Pole Molded Case Circuit Breaker

New

$16.15 In Stock

Quantity

Similar Items

Description

Built for reliable power distribution, the Siemens BQ1B040 is a 1-pole, 40A molded case circuit breaker. It provides essential overcurrent protection for commercial branch circuits. Designed for Siemens infrastructure, this unit mounts into P1, P2, and P3 panelboards. The bolt-on connection offers superior mechanical stability compared to plug-on alternatives in heavy-use environments. With a 10kAIC rating at 120VAC, this breaker meets UL 489 standards. It is HACR rated for HVAC applications.

Specifications

Key specifications
Brand Siemens
Part Number BQ1B040
Series BQ
Amperage 40A
Poles 1
Mounting Style Bolt-On
Voltage 120VAC
Phase 1
AIC Rating 10kA @ 120VAC
Fit and installation
Frame Type BQ
Terminal Type Lugs
For Use With Siemens Panelboards (P1, P2, P3)
Wire Gauge 14-6 AWG (Cu), 12-6 AWG (Al)
Max Wire 6 AWG
Min Wire 14 AWG (Cu), 12 AWG (Al)
Protection and operation
Trip Technology Thermal Magnetic
Trip Function Code LI
Trip Function Long-Time, Instantaneous
Trip Adjustability Fixed
Standards and features
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
Construction Features HACR Rated, HID Rated

Product FAQs

6 answers
Which panelboards accept the Siemens BQ1B040 circuit breaker?

This breaker is specifically designed for bolt-on installation in Siemens P1, P2, and P3 commercial panelboards.

Can I install the BQ1B040 in a standard Siemens residential load center?

No. The BQ1B040 is a bolt-on breaker built for commercial panelboards. Standard Siemens residential load centers require plug-on breakers, such as the QP series.

Is the BQ1B040 suitable for HVAC applications?

Yes, this breaker is HACR rated, meaning it is approved for use with heating, air conditioning, and refrigeration equipment.

What wire gauges and materials can be used with the lugs on this breaker?

The integrated load-side lugs are dual-rated for both copper and aluminum conductors. They accept 14-6 AWG copper wire or 12-6 AWG aluminum wire.

What is the difference between the BQ1B040 and the BQH or HBQ versions?

The BQ1B040 is the standard version with a 10kAIC interrupting rating. The BQH series offers a higher 22kAIC rating, and the HBQ series provides a 65kAIC rating. All three share the same physical dimensions and panelboard compatibility.

Does the BQ1B040 feature an adjustable trip setting?

No, this breaker utilizes a fixed thermal-magnetic trip unit. It provides long-time protection for overloads and instantaneous protection for short circuits, but the trip thresholds cannot be adjusted in the field.

SuperClub

Join free. Get 500 SuperPoints.

Earn points on eligible purchases and redeem them at checkout.

100 SuperPoints = $1 off.

Warranties

60-Day Warranty

Your purchase includes 60 days of SuperBreakers warranty coverage.

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.

Read our full shipping policy

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

4.9
Rated 4.9 out of 5 stars
Based on 73 reviews
Reviews Summary
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.
Rating
Ratings
73 reviews
  • HS
    Hector S.
    Verified Buyer
    Reviewing
    Siemens BQ3B100H - 100A 3 Pole Molded Case Circuit Breaker
    I recommend this product
    Rated 5 out of 5 stars
    9/27/26
    Perfect replacement

    Fit perfectly and good price

  • AF
    Anthony F.
    Verified Buyer
    Reviewing
    Siemens BQ2B020 - 20A 2 Pole Molded Case Circuit Breaker
    I recommend this product
    Rated 5 out of 5 stars
    9/25/26
    works as expected

    works as expected

  • MS
    Mike S.
    Verified Buyer
    Reviewing
    Eaton / Cutler-Hammer BQ250250 - 50/50A Quadplex Miniature Circuit Breaker
    I recommend this product
    Rated 5 out of 5 stars
    8/12/26
    Electrical company

    Breaker worked awesome thank you very much

  • PE
    Philip E.
    Verified Buyer
    Reviewing
    Siemens BQ3B020 - 20A 3 Pole Molded Case Circuit Breaker
    I recommend this product
    Rated 5 out of 5 stars
    8/10/26
    Siemens BQ3B020

    The breaker arrived as described and on time. It works as expected. I will order from SuperBreakers again in the future without hesitation.

  • PL
    Paul L.
    Verified Buyer
    Reviewing
    Siemens BQ1B020 - 20A 1 Pole Molded Case Circuit Breaker
    I recommend this product
    Rated 5 out of 5 stars
    7/23/26
    Breaker

    Quick shipping. Exact fit.