Obsolete Circuit Breakers: Finding Replacement Breakers for Older Electrical Panels

Finding obsolete circuit breakers can be challenging, especially when dealing with older electrical panels that are no longer manufactured. Many homes, commercial buildings, and industrial facilities still rely on discontinued breaker systems, making replacement parts difficult to locate through traditional electrical supply channels.

Fortunately, many obsolete circuit breakers are still available through specialty electrical suppliers. Understanding your options can help you maintain electrical safety, avoid costly downtime, and extend the life of your electrical system.

What Are Obsolete Circuit Breakers?

Obsolete circuit breakers are breakers that are no longer manufactured by the original company. Although production may have ended years ago, many of these breakers remain in service throughout homes, office buildings, apartment complexes, manufacturing facilities, and commercial properties.

In many cases, replacement breakers are still available as new surplus, reconditioned, or professionally tested used inventory.

Common Obsolete Circuit Breaker Brands

Some of the most frequently requested obsolete circuit breaker brands include:

• Federal Pacific (FPE)
• Zinsco
• Challenger
• Pushmatic
• Bulldog
• Bryant
• Westinghouse
• Sylvania
• ITE Legacy Models
• Crouse-Hinds

Many of these systems were installed decades ago and continue operating today, creating ongoing demand for replacement breakers and panel components.

Why Obsolete Breakers Are Still Needed

Replacing an entire electrical panel is not always practical or immediately necessary. Property owners often seek obsolete breakers when:

• A single breaker has failed
• Additional circuits are needed
• A tenant improvement project is underway
• Equipment maintenance requires breaker replacement
• A matching breaker is required for an existing panel

Locating the correct replacement breaker can often save significant time and expense compared to a complete panel replacement.

Federal Pacific (FPE) Breakers

Federal Pacific Electric (FPE) breakers are among the most commonly requested obsolete circuit breakers. While many FPE panels remain in service, replacement breakers can be difficult to locate through standard electrical distributors.

Property owners frequently search for replacement FPE Stab-Lok breakers when maintaining older electrical systems.

Learn more in our guide on Replacing FPE, Zinsco, and Challenger Breakers.

Zinsco Circuit Breakers

Zinsco electrical panels were widely installed throughout the United States and are still found in many older residential and commercial properties. Because original Zinsco equipment is no longer manufactured, replacement breakers often require sourcing from specialty electrical suppliers.

Electrical contractors frequently encounter Zinsco systems during remodeling, panel upgrades, and electrical inspections.

Challenger Circuit Breakers

Challenger breakers remain common in many buildings constructed during the 1980s and 1990s. While some Challenger products were later absorbed into other product lines, finding exact replacement breakers often requires access to surplus or obsolete inventory.

Many electricians seek Challenger replacements when repairing existing electrical systems or upgrading service equipment.

When Should an Obsolete Breaker Be Replaced?

Circuit breakers should be replaced whenever they show signs of failure or damage. Common warning signs include:

• Frequent tripping
• Burn marks or discoloration
• Overheating
• Physical damage
• Breaker will not reset
• Loose connection to the panel

If you notice any of these symptoms, review our guide on Signs of a Bad Circuit Breaker.

Should You Replace the Breaker or Upgrade the Entire Panel?

In some situations, replacing a single obsolete breaker is the most practical solution. In others, a complete electrical panel upgrade may offer greater safety, capacity, and long-term reliability.

Factors to consider include:

• Age of the electrical panel
• Availability of replacement breakers
• Current electrical demand
• Future expansion plans
• Overall condition of the system

Learn more in our guide on When to Upgrade Your Electrical Panel.

Finding Obsolete Circuit Breakers in San Diego

Electrical Supplies Unlimited specializes in locating new, used, surplus, and obsolete circuit breakers throughout San Diego County. Our inventory includes hard-to-find breakers, discontinued models, legacy panel components, and replacement electrical equipment for residential, commercial, and industrial applications.

We help contractors, electricians, property managers, and facility maintenance professionals locate difficult-to-find breakers quickly and efficiently.

Why Choose ESU for Obsolete Circuit Breakers?

With over 40 years of experience serving the electrical industry, ESU has built a reputation as one of San Diego's trusted sources for obsolete electrical equipment. Our extensive inventory and product knowledge allow us to help customers locate replacement breakers that many suppliers no longer carry.

Whether you need a discontinued FPE breaker, Zinsco replacement, Challenger breaker, or another hard-to-find model, our team can help identify the correct solution.

More Circuit Breaker Resources

• Circuit Breaker Resource Hub
• Circuit Breakers San Diego
• Circuit Breaker Replacement Guide
• Replacing FPE, Zinsco, and Challenger Breakers
• Signs of a Bad Circuit Breaker
• Buy Circuit Breakers San Diego

3 Meter  ESU buys and sells new & used Electrical Supplies!

A "3 meter" typically refers to a three-phase electric meter, a device for measuring electrical energy in commercial and industrial settings, though sometimes in high-demand homes. It measures the power from a three-phase electrical supply, which has three separate current carriers and is used to provide more consistent and efficient power for heavy loads compared to a single-phase meter. The meter continuously monitors voltage and current on each of the three phases to calculate and record total energy consumption in kilowatt-hours (kWh). 

Function and application

Measures three-phase power: It is specifically designed for three-phase systems, which are common in industrial facilities, large commercial buildings, and factories.

Calculates energy consumption: The meter multiplies the voltage and current on each of the three phases to calculate the power, then integrates this data over time to provide a reading of total energy use (kWh).

Supports high power loads: The three-phase system provides higher power-carrying capacity and greater energy efficiency, making it suitable for equipment like industrial motors, air conditioners, and compressors.

ESU Inc has proudly served the electrical supply industry for more than 40 years. We carry a wide selection of new, surplus, and recycled electrical supplies for both residential and commercial needs. As a fully stocked Electrical Distributor and Wholesaler, we maintain many different product lines on hand. We specialize in locating hard-to-find items, and our experienced staff is committed to going above and beyond customer expectations. Our reputation speaks for itself—just ask around, or give us a call at 858.558.2850 to experience it firsthand.

Our inventory includes most leading brands such as General Electric, Hammond Power, ITE Siemens, Cutler Hammer, Square D, FPE Federal Pacific, Pushmatic, Zinsco, Crouse Hinds, Challenger, Westinghouse, Sylvania, and Bryant.

Our inventory consists of a large selection of Circuit Breakers, Transformers, Disconnects, Panelboards to 600v, Fuses up to 3000 Amps, Bolt Switch Pullouts, Motor Starters and Relays, Meter sockets, Lighting ballasts, Metal Halide and Sox bulbs. We also carry Lithonia Commercial and residential lighting fixtures as well.

Our Products ESU sells a large and diverse inventory of Electrical Supplies, Electrical Equipment, including Circuit Breakers, Fuses, Transformers, Panelboard switches, Safety switches, Fuseable switches, Meter Sockets, Motor Controllers, Lighting  Ballasts, Bolt switch and much more. We carrier almost all manufacturers including Zinsco, Pushmatic, FPE Federal Pacific, ITE Siemens,  Cutler Hammer, Lutron, Lithonia,, Square D, Challenger and many more. We serve the San Diego and SD County areas and to many other intra and interstate clients. We sell products to fit any requirement or budget. ESU rents Greenlee Wire Pullers, Conduit benders as well as other electrician tools. Talk directly to one of our specialists, Ed, Scott, Kevin or Chris to find out more. So give us a call today at 858.558.2850 and let us serve you

Circuit Breakers Electrical Supplies Unlimited sells and buys both new and used Circuit Breakers, serving Circuit Breakers Linda Vista, San Diego and nearby areas such as Hillcrest, Golden Hill, Bankers Hill, and more. We can also arrange shipment of many products to serve customers outside the region. In addition, we will purchase your used Transformers.

We handle most of the major brands, including Westinghouse, Acme, Cutler Hammer, ITE Siemens, Federal Pacific (FPE), Square D, General Electric, and Zinsco. As a fully stocked Electrical Distributor and Wholesaler, we keep many different product lines readily available.

Electrical Supplies Unlimited is San Diego’s go-to source for Circuit Breaker electrical supplies. Our inventory includes a wide range of circuit breakers across most voltages and amperages. In our San Diego store, we carry products from many manufacturers such as Zinsco, Federal Pacific (FPE), Pushmatic, Bulldog, Cutler Hammer, ITE Siemens, Square D, and more. We stock most amperages and voltages. Some examples of what we offer:

20 Amp thru 125 amp Zinsco breakers
20 amp through 1200 amp 480 volt Siemens breakers 3 phase and single phase
15 thru 100 amp 120/240 Volt Pushmatic Breakers
15 thru 1200 amp 120/240 and 480V Federal Pacific FPE circuit breakers

We are circuit breakers and electrical hardware experts. Do not hesitate to call us at 858.558.2850 to find out which Circuit Breaker is right for your requirement.

Your one stop go to guys. Always at your service!

Circuit Breakers in La Jolla San Diego – New & Used Breakers, Panels & Electrical Supplies

Electrical Supplies Unlimited (ESU) is your trusted source for Circuit Breakers in La Jolla San Diego, serving contractors, electricians, property managers, and homeowners throughout Bay Ho and surrounding communities including Del Mar, Sorento Valley, Hillcrest, Golden Hill, Bankers Hill, and greater San Diego County.

We buy and sell both new and used circuit breakers, electrical panels, transformers, and electrical equipment. Whether you need replacement breakers, obsolete breakers, or hard-to-find electrical components, ESU provides dependable solutions backed by over 40 years of industry experience.

San Diego’s Trusted Circuit Breaker Supplier Since 1985

ESU has proudly served the San Diego electrical supply industry for more than four decades. As a fully stocked electrical distributor and wholesaler, we carry a wide range of residential, commercial, and industrial electrical supplies designed to meet virtually any project requirement.

Our experienced team specializes in locating discontinued, surplus, and specialty electrical products, helping customers source reliable solutions quickly and efficiently.

Leading Circuit Breaker Brands Available

Our extensive inventory includes major circuit breaker manufacturers and trusted industry brands, including:

General Electric (GE), Siemens / ITE, Cutler Hammer, Square D, Federal Pacific (FPE), Pushmatic, Zinsco, Challenger, Bryant, Westinghouse, Sylvania, Crouse Hinds, Bulldog, and many more.

Complete Electrical Supply Inventory

In addition to circuit breakers, ESU stocks a large inventory of:

• Transformers
• Panelboards up to 600V
• Disconnects & Safety Switches
• Fuses up to 3000 Amps
• Meter Sockets
• Motor Starters & Relays
• Lighting Ballasts & Fixtures
• Bolt Switch Pullouts
• Commercial & Residential Electrical Supplies

We also offer Greenlee tool rentals, conduit benders, wire pullers, and additional electrician equipment for contractors throughout San Diego County.

Specialists in New, Used & Obsolete Circuit Breakers

ESU is San Diego’s go-to source for new, used, surplus, and obsolete circuit breakers. We carry a broad range of amperages and voltages for nearly every major electrical system.

Examples of our inventory include:

• 20 Amp to 125 Amp Zinsco breakers
• 15 Amp to 100 Amp Pushmatic breakers
• 20 Amp to 1200 Amp Siemens breakers
• 15 Amp to 1200 Amp Federal Pacific (FPE) breakers
• Single-phase and 3-phase commercial breakers

Whether you need residential breaker replacements, commercial electrical upgrades, or industrial breaker solutions, our knowledgeable staff can help you select the right product for your project.

Serving La Jolla & Greater San Diego

We proudly provide circuit breakers and electrical supplies throughout:

• Allied Gardens
• Hillcrest
• Golden Hill
• Bankers Hill
• University City
• Vista
• Oceanside
• Carlsbad
• San Marcos
• All San Diego County

We also ship many products nationwide for customers outside the San Diego region.

Your Local Circuit Breaker Experts

At Electrical Supplies Unlimited, we combine decades of electrical supply expertise with one of the region’s most diverse inventories of circuit breakers and electrical equipment.

Whether you’re replacing outdated breakers, sourcing specialty equipment, or upgrading electrical infrastructure, ESU delivers dependable products, expert guidance, and exceptional customer service.

Call ESU today at 858.558.2850 to speak directly with one of our electrical supply specialists and find the right circuit breaker or electrical solution for your needs.

Tandem Circuit Breakers: What They Are and When to Use Them

A tandem circuit breaker is a special type of breaker that allows two separate circuits to be installed in a single slot within an electrical panel. These breakers are often used when a panel runs out of space but additional circuits are needed.

Understanding how tandem breakers work, when they are allowed, and whether they are safe is essential for homeowners, electricians, and contractors working with residential electrical systems.

What Is a Tandem Circuit Breaker?

A tandem circuit breaker (sometimes called a “double” or “cheater” breaker) combines two individual breakers into one unit that fits into a single panel slot. Each circuit operates independently, providing the same protection as a standard single-pole breaker.

This allows an electrical panel to support more circuits without physically expanding the panel.

When Are Tandem Breakers Used?

Tandem breakers are typically used when an electrical panel has no available space for additional circuits. Common situations include:

• Home renovations or additions
• Installing new appliances or equipment
• Adding circuits for kitchens, garages, or HVAC systems
• Upgrading electrical capacity without replacing the panel

They provide a convenient solution when space is limited, but they are not always the best long-term option.

Are Tandem Circuit Breakers Safe?

Yes, tandem circuit breakers are safe when used correctly and installed in panels that are specifically designed to accept them. Electrical panels have a maximum number of circuits they can safely handle, and tandem breakers should only be used within those limits.

Installing tandem breakers in a panel that is not rated for them can lead to overheating, code violations, and potential electrical hazards.

Are Tandem Breakers Legal?

Tandem breakers are legal when used in accordance with the panel manufacturer’s specifications and local electrical codes. Most panels include labeling that indicates how many tandem breakers are allowed and in which positions they can be installed.

If too many circuits are added beyond the panel’s rating, it may be necessary to upgrade the panel instead.

Tandem Breaker vs Standard Breaker

Understanding the difference between tandem and standard breakers is important when planning electrical upgrades:

• Standard Breaker: Occupies one slot and controls one circuit
• Tandem Breaker: Occupies one slot but controls two separate circuits

While tandem breakers increase circuit capacity, they do not increase the total electrical load capacity of the panel.

Tandem Breakers vs Double-Pole Breakers

Tandem breakers are sometimes confused with double-pole breakers, but they serve different purposes:

• Tandem Breaker: Two independent 120V circuits
• Double-Pole Breaker: One 240V circuit for large appliances

Using the correct type of breaker is critical for proper electrical system function.

When You Should Upgrade Your Electrical Panel

If you find yourself needing multiple tandem breakers to add circuits, it may be a sign that your panel is undersized for your electrical needs. In these cases, upgrading to a larger panel may be the safer and more reliable solution.

Learn more about upgrade costs in our guide to circuit breaker panel upgrade cost.

Choosing the Right Circuit Breaker

Selecting the correct breaker for your panel ensures safe and reliable operation. Breakers must be compatible with your panel brand and rated for the correct electrical load.

For more guidance, visit our How to Choose the Right Circuit Breaker guide.

Explore More Circuit Breaker Resources

For additional information on breaker types, troubleshooting, and electrical safety, visit our Circuit Breaker Resource Hub.