Zinsco QFP2125K Molded Case Circuit Breaker
- 125A
- 2 Pole
- Plug-On
Quantity
Zinsco QFP2125K - 125A 2 Pole Molded Case Circuit Breaker
New
Quantity
Description
Built with unique offset lugs, this 125-amp two-pole main breaker accommodates specific wiring constraints in older electrical systems. It fits into vintage Zinsco load centers, restoring functionality without requiring extensive modifications. The unit utilizes proven thermal-magnetic elements to deliver reliable 10kAIC protection at 120/240VAC. For modern cross-reference needs, the UBITBFP1252 serves as an approved substitute.Specifications
| Brand | Zinsco |
|---|---|
| Series | QFP |
| Amperage | 125A |
| Poles | 2 |
| Mounting Style | Plug-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Zinsco Load Centers |
| Wire Gauge | 1 AWG - 300 kcmil |
| Max Wire | 300 kcmil |
| Min Wire | 1 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Accessories | Load Side Lugs Included |
|---|---|
| Standards | UL 489 |
| Approval | UL |
| Temp Rating | 40C |
| Construction Features | Main Breaker, Offset Lugs |
Product FAQs
6 answersWhat load centers are compatible with the Zinsco QFP2125K?
The QFP2125K is designed for use as a main breaker in legacy Zinsco load centers that accept QFP frame plug-in circuit breakers. It is also compatible with specific Sylvania and Challenger panels that utilize the same proprietary Zinsco style busbar design.
Are there modern aftermarket replacements for the Zinsco QFP2125K?
Yes. Connecticut Electric manufactures new aftermarket replacements for legacy Zinsco breakers. The direct replacement for the 125A QFP type main breaker is catalog number UBITBFP1252, which is ETL listed to UL standards for use in these older enclosures.
Can I use a Sylvania or Challenger breaker in place of the Zinsco QFP2125K?
Yes. Following the acquisition of Zinsco, identical breakers were manufactured under the Sylvania, Challenger, and Thomas & Betts brand names. A QFP2125K branded by any of these manufacturers is physically and electrically identical and can be used interchangeably.
How does the QFP2125K connect to the panel busbar?
This breaker features a plug-in connection type specific to Zinsco's proprietary busbar design. It pushes directly onto the vertical busbars in the load center, while the load side connections are secured using mechanical lugs that accept 1 AWG to 300 kcmil wire.
Are there known safety concerns with legacy Zinsco panels and breakers?
Yes. Legacy Zinsco panels and breakers have a documented history of failing to trip during overcurrent events and experiencing busbar arcing or melting. Many licensed electricians and home inspectors recommend replacing the entire Zinsco load center with a modern panel to ensure electrical safety and code compliance.
Does the QFP2125K provide ground fault or arc fault protection?
No. The QFP2125K is a standard thermal magnetic breaker providing only long-time overload and instantaneous short-circuit protection. It does not include GFCI or AFCI circuitry.
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 5.0 out of 5 based on 3 reviews.
- KYKathleen Y.Verified BuyerReviewingMilbank UQFP-100 2 Pole Circuit BreakerI recommend this productRated 5 out of 5 stars1/1/26Milbank 100 2 Pole Circuit Breaker
Product arrived on time, well packaged and exactly what we needed.
Jake was extremely helpful and courteous. You don’t find that too often these days. Will spread the word and recommend your company to all that require your service.
Thank you and Happy New Year
Sincerely,
K. Young
- QAquinlan a.Verified BuyerReviewingZinsco QFP2200T - 200A 2 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars8/26/25Great communication and customer service
Ordered QFP2200T breaker and paid to ship overnight. Reached out to company when breaker did not arrive on time. Although I did not get the breaker when expected, they did communicate the situation, refunded my shipping and expedited the breaker to me once it was ready for shipping. They handled the situation in the best possible way given the circumstances.
Would buy from them again.
-Quinlan (Q-Extra Electrical Services)
- ARAized R.ReviewingZinsco QFP2200T - 200A 2 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars10/7/21Excellent service!
I needed an obsolete part. They had it and sent it. Turned out it was the wrong part. Their customer service made up for it. They sent the correct part overnight and also sent a free ups label to return the wrong part. Great service! Highly recommend. And the refurbished part looked like it was in great shape.