Zinsco R3840 2-Pole 40 Amp Molded Case Circuit Breaker

NEW:

Breaker is brand new in box and ships with original manufacturer packaging. It has never been installed or energized. In most cases, the packaging is unopened.

USED:

Breaker has been previously energized and/or installed and is reconditioned and tested by our certified technicians before shipping. All used breakers meet original OEM standards.

All breakers come with a minimum one-year replacement warranty, with some new items carrying multi-year factory-backed warranties.

Zinsco circuit breakers were commonly installed in residential electrical panels during the 1960s and 1970s and remain present in many older homes and small commercial buildings. Electricians often recognize these panels by their distinctive colored breaker handles and aluminum bus bar designs.

While Zinsco equipment was widely used during its time, the company eventually ceased operations, and many original breakers are no longer manufactured. Additionally, some Zinsco panel designs have been associated with reliability concerns over the years, leading many electricians to recommend panel replacement when possible.

Despite this, existing Zinsco panels are still encountered in the field, and replacement breakers are sometimes required for maintenance or temporary repairs. Because original breakers are obsolete, replacement options include breakers manufactured by companies such as Connecticut Electric, designed to fit existing Zinsco panels, or  tested and reconditioned used breakers, though system upgrades are often recommended when feasible.