Zinsco QB243030 Molded Case Circuit Breaker
- 30A
- 3 Pole
- Bolt-On
Quantity
Zinsco QB243030 - 30A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Description
Part of the classic Magnatrip family, this 30A, 3-pole molded case circuit breaker delivers essential overcurrent protection for 240V commercial environments. It features fixed thermal-magnetic trip functions with a 10kAIC interrupt capacity. This bolt-on breaker is engineered to fit into legacy Zinsco panelboards, offering a reliable solution for aging electrical systems. It serves as a hardware match for UBIZ243030 substitute models.Specifications
| Brand | Zinsco |
|---|---|
| Part Number | QB243030-R |
| Series | QB |
| Amperage | 30A |
| Poles | 3 |
| Mounting Style | Bolt-On |
| Voltage | 240VAC |
| Phase | 3 |
| AIC Rating | 10kA @ 240VAC |
| Frame Type | QB2430 |
|---|---|
| Terminal Type | Lugs |
| For Use With | Zinsco Panelboards |
| Wire Gauge | 14-6 AWG (Al/Cu) |
| Max Wire | 6 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 | UL 489 |
| Approval | UL |
| Temp Rating | 40C |
| Construction Features | Magnatrip, Color Coded Handle (Green) |
Product FAQs
6 answersWhich panelboards accept the Zinsco QB243030 circuit breaker?
This breaker is engineered exclusively for legacy Zinsco commercial and industrial panelboards that require QB series bolt-on breakers. It is not interchangeable with standard plug-on Zinsco Q series load centers.
Is there a direct cross-reference or modern substitute for the QB243030?
Yes, the Connecticut Electric UBIZ243030 is a newly manufactured, drop-in replacement that matches the physical dimensions and electrical specifications of the original Zinsco QB243030.
What is the correct wire gauge range for the load terminals on this breaker?
The load side lugs are rated to accept either copper or aluminum conductors ranging from 14 AWG up to 6 AWG. Ensure proper torque specifications are followed during installation to prevent terminal overheating.
Does the QB243030 require a mounting kit or adapter for installation?
No adapter kits are required. This molded case circuit breaker features a direct bolt-on design that mounts straight into existing Zinsco enclosures.
What applications are suitable for the 10kAIC rating on this breaker?
A 10,000 Ampere Interrupting Capacity at 120/240V is typical for standard residential and light commercial subpanels. It indicates the maximum fault current the breaker can safely clear, so you must verify that the available fault current at the panel does not exceed 10kA.
Are there known safety issues with legacy Zinsco electrical equipment?
Yes, original Zinsco panels and breakers have a documented history of reliability concerns, including breakers failing to trip during overcurrent events and poor busbar connections that can lead to arcing. Many electrical professionals recommend a complete panel upgrade when possible.
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Reviews
Review summary
Customers rate this product 5.0 out of 5 based on 1 review.
- MCMarcos C.Verified BuyerReviewingEaton / Cutler-Hammer QB1030GF - 30A GFCI Miniature Circuit BreakerI recommend this productRated 5 out of 5 stars11/20/25circuit breakers
good product and showed up on time