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Federal Pacific NB221050 Miniature Circuit Breaker
- 50A
- 2 Pole
- Bolt-On
Federal Pacific
NB221050
Miniature Circuit Breaker
Brand
Federal Pacific
SKU
NB221050
Quantity
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Federal Pacific NB221050 - 50A 2 Pole Miniature Circuit Breaker
New
Quantity
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Federal Pacific NB221050 - 50A 2 Pole Miniature Circuit Breaker
New
Quantity
| Brand | Federal Pacific |
|---|---|
| Part Number | NB221050 |
| Series | NB |
| Amperage | 50A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Federal Pacific NB Panelboards |
| Wire Gauge | 14-2 AWG (Al/Cu) |
| Max Wire | 2 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Accessories | Load Side Lugs Included |
|---|---|
| Standards | CSA C22.2 No. 5, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
Sold out
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Federal Pacific NB221050 - 50A 2 Pole Miniature Circuit Breaker
Re-Certified
Quantity
| Brand | Federal Pacific |
|---|---|
| Part Number | NB221050-R |
| Series | NB |
| Amperage | 50A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Federal Pacific NB Panelboards |
| Wire Gauge | 14-2 AWG (Al/Cu) |
| Max Wire | 2 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Accessories | Load Side Lugs Included |
|---|---|
| Standards | CSA C22.2 No. 5, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
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Description
Engineered to support commercial and industrial loads, this 50-amp miniature circuit breaker provides vital thermal-magnetic protection. It ensures continuous operation for facilities relying on older distribution equipment. The unit bolts seamlessly into legacy Federal Pacific NB panelboards, offering a reliable alternative to the UBIF250NB. This exact physical match eliminates the hassle of sourcing adapter hardware for aging enclosures.Specifications
| Brand | Federal Pacific |
|---|---|
| Part Number | NB221050 |
| Series | NB |
| Amperage | 50A |
| Poles | 2 |
| Mounting Style | Bolt-On |
| Voltage | 120/240VAC |
| Phase | 1 |
| AIC Rating | 10kA @ 120/240VAC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Federal Pacific NB Panelboards |
| Wire Gauge | 14-2 AWG (Al/Cu) |
| Max Wire | 2 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Accessories | Load Side Lugs Included |
|---|---|
| Standards | CSA C22.2 No. 5, UL 489 |
| Approval | CSA, UL |
| Temp Rating | 40C |
Product FAQs
6 answersCan the NB221050 be installed in a standard Federal Pacific residential load center?
No. The NB221050 is a bolt-on breaker designed exclusively for Federal Pacific NB commercial panelboards. It will not fit into residential Stab-Lok enclosures, which require plug-on NA or NC series breakers.
What is the direct replacement for an obsolete NB221050 breaker?
The Connecticut Electric UBIF250NB is an ETL-listed, direct drop-in replacement for the NB221050. It matches the physical dimensions and electrical specs, allowing it to bolt into legacy NB panelboards without modifications.
Does the NB221050 require special mounting hardware for installation?
No adapter kits are required when installing this breaker into a compatible Federal Pacific NB panelboard. It uses a standard bolt-on configuration that fastens directly to the existing busbar.
What does the LI trip function code mean for the NB221050?
The LI code indicates that this thermal magnetic breaker provides Long-Time and Instantaneous protection. The thermal element prevents overheating from sustained overloads, while the magnetic element clears short circuits immediately.
Is the NB221050 subject to the same safety issues as Federal Pacific Stab-Lok breakers?
The NB series are commercial-grade, bolt-on molded case circuit breakers. They use a completely different internal design and mounting mechanism than the residential Stab-Lok plug-on breakers, which are the primary focus of industry safety warnings.
What are the conductor limits for the NB221050 load terminals?
The factory-installed lugs accept wire sizes from 14 AWG up to 2 AWG. They are dual-rated for both aluminum and copper (Al/Cu) conductors, making them versatile for existing commercial wiring setups.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 18 reviews.
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Rating
18 reviews
- MMMike M.Verified BuyerReviewingFederal Pacific NB100 - 100A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars7/2/26100amp federal pacific breaker
So far the breaker works as expected
Just good to know some of these old federal are still available.
Thank you
- SGscott g.Verified BuyerReviewingFederal Pacific NB111020 - 20A 1 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars6/26/26Hard to find breakers
Had a project at a school built in the 1960’s and thought we were up a creek when confronted with ancient FPE commercial panels. Luckily we found what we needed with Suoerbreakers.
- BFBarry F.Verified BuyerReviewingFederal Pacific NB100 - 100A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars6/13/26Hard to find circuit breaker
Item was as described.
- WWWilliam W.Verified BuyerReviewingFederal Pacific NB100 - 100A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars3/9/26Exactly what I needed.
Awesome! Packaging and delivery were good. Bolted in and worked perfectly!!)
- GHGary H.Verified BuyerReviewingFederal Pacific NB125 - 125A 2 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars3/3/26Federal Pacific NB125 2 Pole Circuit Breaker
Federal Pacific NB125 2 Pole Circuit Breaker
Great product and excellent price and warranty.