Molded Case Circuit Breakers (MCCBs)

New, Recertified & Obsolete MCCBs — In Stock and Ready to Ship

Key Takeaways:

• Essential Electric Supply offers new, recertified, surplus, and obsolete MCCBs with same-day shipping for urgent needs. 

• MCCBs protect electrical systems by automatically disconnecting power during overloads or short circuits. 

• These breakers typically cover 10–1600A and up to 600V, making them ideal for commercial and industrial applications. 

• Recertified MCCBs are tested to OEM specifications and include a two-year warranty and 30-day return policy. 

• Hard-to-find and discontinued MCCBs are available, with expert support to identify compatible replacements quickly.

Essential Electric Supply is a trusted power distribution supplier for hard-to-find and in-stock Molded Case Circuit Breakers (MCCBs), delivering new, recertified, surplus, and obsolete units with same-day shipping to electricians and contractors. When downtime isn’t an option, our extensive North American inventory ensures you get the exact breaker you need fast, even for discontinued or difficult-to-source models.

A molded case circuit breaker (MCCB) is an electrical device that protects circuits from overload and short circuits. When an issue occurs, it automatically disconnects the power supply and protects the system from harm. MCCBs are available in various ratings and are built for high and low voltage systems, typically covering 10 to 1600A and voltages up to 600V.

They are equipped with either a thermal-magnetic trip unit or an electronic trip unit, which provides more precise, adjustable protection curves. For most commercial and industrial branch circuit applications, the thermal-magnetic unit is the standard choice. However, electronic trip units are preferred when adjustable settings are required for complex or high-demand loads. Common installation environments include residential panels, panelboards, and switchboards.

Shop Our Molded Case Circuit Breakers

We stock new, recertified, surplus, and obsolete MCCBs in one place, from current production lines to hard-to-find discontinued parts. Our inventory spans brands that most distributors stopped carrying years ago, including:

• Siemens, Eaton, Square D, Schneider Electric, Cutler-Hammer, GE, ABB, ITE

• Obsolete and discontinued lines: Federal Pioneer, Westinghouse, Zinsco, FPE

With same-day shipping available on in-stock orders placed by 1:30 PM PST, multiple ship points across North America, and 24-hour emergency support, we're built for the jobs that can't wait.

Every recertified molded case circuit breaker is tested to OEM specifications before it ships. If the exact part you need has been discontinued, our team can identify authorized replacements and retrofits compatible with your existing panel, so you're not left troubleshooting compatibility issues on-site. 

For urgent orders or large-volume requests, call Essential Electric Supply’s 24-hour support line or submit a quote request, and we’ll get back to you fast.

Every order ships with:

• Same-day shipping on in-stock orders placed before 1:30 PM PST

• 24-hour emergency support line for urgent needs

• Two-year warranty on all recertified units

• 30-day return policy on all orders

Frequently Asked Questions

Do you offer same-day shipping on molded case circuit breakers?

Yes. Orders placed by 1:30 PM PST on in-stock MCCBs ship the same day via UPS. We offer free UPS Ground shipping on orders over $250 within the continental United States. For time-critical situations, expedited after-hours air delivery is also available. With multiple shipping points across North America, most customers receive their parts quickly regardless of location.

Do you stock obsolete and discontinued molded case circuit breaker brands?

Yes. We carry obsolete and discontinued MCCBs from brands including Federal Pioneer, Westinghouse, Zinsco, FPE, and discontinued lines from Square D, GE, ABB, Cutler-Hammer, ITE, and Siemens. If you're working on an aging panel and can't find the part through standard channels, our team specializes in locating hard-to-find and out-of-production breakers. Contact us directly with your part number or breaker label information, and we'll track it down.

Are your recertified MCCBs tested before shipping?

Yes. Every recertified molded case circuit breaker is tested to OEM specifications before it leaves our warehouse. Recertified units ship with our two-year warranty — the same coverage we apply to new stock — and all orders are backed by our 30-day return policy. We stand behind the quality of every part we ship.

What if the MCCB I need is no longer available?

Reach out to our team, and we'll help find what you need. To move quickly, have your catalog number or part number ready, and if possible, take photos of the breaker label from multiple angles — the amperage, voltage rating, frame size, and trip type are all key details. From there, our team can identify authorized replacements or retrofits that are compatible with your existing panel, so you're not stuck waiting on a part that no longer exists.