Zinsco Q243050 Molded Case Circuit Breaker
- 50A
- 3 Pole
- Plug-On
Quantity
Zinsco Q243050 - 50A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Description
Built to maintain legacy electrical systems, this three-pole 50A breaker handles commercial and industrial loads. The plug-on design ensures a secure fit into classic Zinsco panelboards without requiring aftermarket adapters. Equipped with proven Magnetrip functionality and a standard black handle, it provides essential long-time and instantaneous trip responses. The HACR-rated component supports 8-4 AWG conductors and serves as a primary alternative to the UBIZ243050.Specifications
| Brand | Zinsco |
|---|---|
| Part Number | Q243050-R |
| Series | Q |
| Amperage | 50A |
| Poles | 3 |
| Mounting Style | Plug-On |
| Voltage | 240VAC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC |
| Terminal Type | Lugs |
|---|---|
| For Use With | Zinsco Load Centers |
| Wire Gauge | 8-4 AWG |
| Max Wire | 4 AWG |
| Min Wire | 8 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed |
| Standards | UL 489 |
|---|---|
| Approval | UL |
| Temp Rating | 40C |
| Construction Features | Magnetrip, Color-Coded Handle (Black) |
Product FAQs
6 answersWhat panels accept the Zinsco Q243050 circuit breaker?
The Q243050 is engineered specifically for legacy Zinsco load centers and panelboards that require Q-series plug-on breakers. It cannot be installed in modern panels from manufacturers like Square D, Siemens, or Eaton.
What is the modern aftermarket equivalent for the Zinsco Q243050?
The Connecticut Electric UBIZ243050 serves as a direct substitute for the original Zinsco Q243050. It is manufactured to fit the same vintage Zinsco load centers.
Why are legacy Zinsco panels and breakers often flagged during electrical inspections?
Original Zinsco electrical equipment is obsolete and has documented design flaws, particularly concerning the connection between the breaker and the aluminum bus bar. These flaws can lead to arcing, overheating, and a failure to trip under fault conditions. Upgrading to a modern panel is highly recommended by industry professionals.
Does the Q243050 require any special adapters for installation?
No, this breaker utilizes a standard plug-on mounting design that connects directly to the bus bar of compatible vintage Zinsco panels without requiring aftermarket adapters or modification kits.
What is the conductor capacity for the Q243050 terminal lugs?
The mechanical lugs on this 50-amp breaker are designed to accommodate wire gauges from 8 AWG up to 4 AWG. Ensure proper torque specifications are followed during installation to maintain a secure connection.
How does the trip mechanism function on the Q243050 breaker?
It features a fixed thermal-magnetic trip unit. The thermal component provides a long-time delay to prevent nuisance tripping from temporary surges, while the magnetic component delivers an instantaneous response to clear severe short circuits.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 47 reviews.
- CGCrocefissa G.Verified BuyerReviewingSiemens Q115 - 15A 1 Pole Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars9/18/26Quick delivery and great price.
The circuit breakers are at a great cost.
- JBJason B.Verified BuyerReviewingSiemens Q2150B - 150A 2 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars9/18/26Great experience
The product was exactly what I needed and it arrived on time.
- DQDon Q.Verified BuyerReviewingSiemens Q3100 - 100A 3 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars9/14/26Siemens breaker
Great customer experience, great prices and fast shipping... Definitely will be buying her again.
- CSChristopher S.Verified BuyerRated 5 out of 5 stars8/12/26Siemens 60
Perfect new condition
- GSGeorge S.Verified BuyerReviewingSiemens Q2150B - 150A 2 Pole Molded Case Circuit BreakerI recommend this productRated 5 out of 5 stars3/4/26Great service
Every time I call or go online you have the parts I'm looking for.