Zinsco QB243020 Molded Case Circuit Breaker
- 20A
- 3 Pole
- Bolt-On
Quantity
Zinsco QB243020 - 20A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
Quantity
Zinsco QB243020 - 20A 3 Pole Molded Case Circuit Breaker
New
Quantity
| Brand | Zinsco |
|---|---|
| Part Number | QB243020 |
| Series | QB |
| Amperage | 20A |
| 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 | 14-8 AWG (Al/Cu) |
| Max Wire | 8 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Fixed Magnetic |
| Accessories | Load Side Lugs Included |
|---|---|
| Standards | UL 489 |
| Approval | UL |
| Temp Rating | 40C |
| Construction Features | Common Trip |
Quantity
Zinsco QB243020 - 20A 3 Pole Molded Case Circuit Breaker
Re-Certified
Quantity
| Brand | Zinsco |
|---|---|
| Part Number | QB243020-R |
| Series | QB |
| Amperage | 20A |
| 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 | 14-8 AWG (Al/Cu) |
| Max Wire | 8 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Fixed Magnetic |
| Accessories | Load Side Lugs Included |
|---|---|
| Standards | UL 489 |
| Approval | UL |
| Temp Rating | 40C |
| Construction Features | Common Trip |
Description
Rated for 20 amps, the Zinsco QB243020 is a 3-pole molded case circuit breaker designed for commercial and industrial applications. It provides essential long-time and instantaneous protection for 3-phase electrical circuits. This legacy component mounts into existing Zinsco panelboards, allowing facilities to maintain their current infrastructure. If a modern alternative is required, it can be substituted with the UBIZ243020.Specifications
| Brand | Zinsco |
|---|---|
| Part Number | QB243020-R |
| Series | QB |
| Amperage | 20A |
| 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 | 14-8 AWG (Al/Cu) |
| Max Wire | 8 AWG |
| Min Wire | 14 AWG |
| Trip Technology | Thermal Magnetic |
|---|---|
| Trip Function Code | LI |
| Trip Function | Long-Time, Instantaneous |
| Trip Adjustability | Fixed Thermal, Fixed Magnetic |
| Accessories | Load Side Lugs Included |
|---|---|
| Standards | UL 489 |
| Approval | UL |
| Temp Rating | 40C |
| Construction Features | Common Trip |
Product FAQs
5 answersWhat panels accept the Zinsco QB243020 circuit breaker?
The QB243020 is a bolt-on molded case circuit breaker designed exclusively for legacy Zinsco commercial and industrial panelboards. It will not fit in standard residential load centers or panels from other manufacturers.
Is there a modern cross-reference for the obsolete Zinsco QB243020?
Yes. Since original Zinsco breakers are no longer manufactured, Connecticut Electric produces the UBIZ243020 as a direct, newly manufactured substitute for this 20A, 3-pole breaker.
What safety issues are associated with legacy Zinsco breakers?
Zinsco panels and breakers have a documented history of failure. The breakers are known to fail to trip during overloads. Additionally, poor connections can cause arcing, overheating, and the breaker welding itself to the busbar. Many inspectors recommend a complete panel upgrade.
What wire gauge is required for the QB243020 terminals?
The load lugs on this breaker accept 14 AWG to 8 AWG wire and are rated for both aluminum and copper conductors.
How does the trip unit function on the QB243020?
It features a fixed thermal-magnetic trip unit with long-time and instantaneous (LI) functions. The thermal component responds to prolonged overloads, while the magnetic component trips immediately during a short circuit.
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 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