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Siemens MBK125A - 125A 2 Pole Main Breaker Kit

Brand Siemens
SKU MBK125A
Siemens MBK125A 2 Pole Circuit Breaker
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Siemens MBK125A - 125A 2 Pole Main Breaker Kit

Brand Siemens
SKU MBK125A
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Siemens MBK125A 2 Pole Circuit Breaker

Siemens MBK125A - 125A 2 Pole Main Breaker Kit

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$114.80 In stock

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DescriptionSpecificationsSuperClubWarranties
Description
Part of the SENTRON family, the Siemens MBK125A is a 125A main breaker conversion kit designed for residential applications. It provides essential long-time and instantaneous (LI) protection for single-phase electrical systems. This bolt-on unit mounts into Siemens Ultimate, PL Series, and ES Series load centers. It serves as a replacement for the legacy MBK125, ensuring a seamless upgrade for existing panelboards. Rated to handle 22kAIC at 120/240VAC, the kit includes mounting hardware.

Specifications

Brand Siemens
Series MBK
Part Number MBK125A
Amperage 125A
Voltage 120/240VAC
Poles 2
Phase 1
AIC Rating 22kA @ 120/240VAC
Mounting Style Bolt-On
Terminal Type Lugs
For Use With Siemens Ultimate Load Centers, PL Series, ES Series
Trip Technology Thermal Magnetic
Trip Function Code LI
Trip Function Long-Time, Instantaneous
Trip Adjustability Fixed Thermal, Fixed Magnetic
Wire Gauge 4 AWG - 2/0 AWG (Cu/Al)
Max Wire 2/0 AWG
Min Wire 4 AWG
Accessories Mounting Hardware, Line Side Lugs Included
Standards UL 489, CSA C22.2
Approval CSA, UL
Temp Rating 40C
Construction Features Main Breaker Kit, 22kA Interrupt Rating, HACR Rated, For Ultimate Load Centers

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Warranties

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When shopping with SuperBreakers, you’ll have peace of mind knowing that every single item you purchase includes a 60 day warranty, free of charge. Why such confidence? Because only the highest quality electrical parts have a place on our shelves, and we stand by every single one we sell.

If anything goes wrong with your item that is not a result of misuse or normal wear and tear, we’ll gladly replace it at no cost to you.

Click here to read our full warranty details

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.

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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.
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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.

4.9
Rated 4.9 out of 5 stars
Based on 7 reviews
Total 5 star reviews: 6 Total 4 star reviews: 1 Total 3 star reviews: 0 Total 2 star reviews: 0 Total 1 star reviews: 0
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7 reviews
  • RN
    Roderick N.
    Verified Buyer
    Reviewing
    Siemens MBK200 2 Pole Circuit Breaker
    I recommend this product
    Rated 5 out of 5 stars
    7/29/25
    Exact replacement!

    Exact replacement 👍

    Was this helpful?
  • WK
    William K.
    Verified Buyer
    Reviewing
    Siemens MBK175A - 175A 2 Pole Main Breaker Kit
    I recommend this product
    Rated 5 out of 5 stars
    7/29/25
    Works perfey

    Brand new, just as described. This was an odd amperage amount to stock, I'm glad they had this.

    Was this helpful?
  • MB
    Mike B.
    Flag of United States
    Reviewing
    Siemens MBK200A - 200A 2 Pole Main Breaker Kit
    I recommend this product
    Rated 5 out of 5 stars
    3/11/21
    Classy Breaker

    Brand new item, came packaged well. Quick deliverly

    Was this helpful?
  • FB
    Frank B.
    Flag of United States
    Reviewing
    Siemens MBK200A - 200A 2 Pole Main Breaker Kit
    I recommend this product
    Rated 5 out of 5 stars
    2/7/19
    Great company would like to

    Great company would like to see orders shipped more quickly

    Was this helpful?
  • RD
    Richard D.
    Flag of United States
    Reviewing
    Siemens MBK200 2 Pole Circuit Breaker
    I recommend this product
    Rated 4 out of 5 stars
    1/2/19
    CEO

    I’m working with Adam on a return right now

    I’ll let you know the outcome

    Was this helpful?

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