Circuit Breakers University City San Diego – New & Used Breakers, Panels & Electrical SuppliesElectrical Supplies Unlimited (ESU) is your trusted source for Circuit Breakers in University City San Diego, serving contractors, electricians, property managers, and homeowners throughout University City and surrounding communities including University Heights, 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.
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.
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.
In addition to circuit breakers, ESU stocks a large inventory of:
We also offer Greenlee tool rentals, conduit benders, wire pullers, and additional electrician equipment for contractors throughout San Diego County.
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:
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.
We proudly provide circuit breakers and electrical supplies throughout:
We also ship many products nationwide for customers outside the San Diego region.
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Whether you’re replacing outdated breakers, sourcing specialty equipment, or upgrading electrical infrastructure, ESU delivers dependable products, expert guidance, and exceptional customer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.
Circuit Breakers Kearney Mesa San DiegoElectrical Supplies Unlimited (ESU) is your trusted source for Circuit Breakers in Kearney Mesa San Diego, serving contractors, electricians, property managers, and homeowners throughout Pacific Beach and surrounding communities including La Jolla, 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.
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.
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.
In addition to circuit breakers, ESU stocks a large inventory of:
We also offer Greenlee tool rentals, conduit benders, wire pullers, and additional electrician equipment for contractors throughout San Diego County.
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:
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.
We proudly provide circuit breakers and electrical supplies throughout:
We also ship many products nationwide for customers outside the San Diego region.
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.
If your circuit breaker is not resetting, it is usually a sign of an underlying electrical problem that needs attention. A breaker that immediately trips again, feels loose, or refuses to stay in the ON position may indicate an overloaded circuit, short circuit, ground fault, or a defective breaker.
Understanding why a circuit breaker will not reset can help you identify potential safety hazards and determine whether you need a simple repair, breaker replacement, or a larger electrical upgrade.
Why Is My Circuit Breaker Not Resetting?Circuit breakers are designed to shut off power when they detect dangerous conditions such as overloads or short circuits. If the underlying issue still exists, the breaker may refuse to reset in order to protect your electrical system.
In some cases, the breaker itself may be worn out or damaged and require replacement.
Many people do not realize that a tripped breaker must first be switched completely to the OFF position before it can be reset.
To properly reset a breaker:
If the breaker immediately trips again, further troubleshooting is required.
One of the most common causes of a breaker that will not reset is an overloaded circuit. Too many devices operating on the same circuit can exceed the breaker's rated capacity.
Try unplugging appliances, electronics, and equipment connected to the affected circuit before attempting to reset the breaker again.
If overloading is a recurring problem, you may need additional circuits or an electrical panel upgrade.
A short circuit occurs when electrical current follows an unintended path with little resistance. Short circuits can generate significant heat and may cause the breaker to trip instantly.
Signs of a possible short circuit include:
Short circuits should be investigated immediately to prevent potential fire hazards.
Ground faults are especially common in kitchens, bathrooms, garages, outdoor circuits, and areas exposed to moisture. Ground fault conditions can cause both standard breakers and GFCI circuit breakers to trip.
If moisture or damaged wiring is present, the breaker may continue tripping until the fault is corrected.
Like any electrical component, circuit breakers can wear out over time. Older breakers may become weak, fail internally, or lose their ability to properly reset.
Common signs of a bad breaker include:
Learn more in our guide on Signs of a Bad Circuit Breaker.
If troubleshooting confirms that the breaker itself is defective, replacement is often the safest solution. Modern breakers provide improved reliability and protection compared to aging or obsolete models.
Read our complete Circuit Breaker Replacement Guide to learn more about selecting the correct replacement breaker.
Some older electrical panels may have recurring breaker problems because the panel itself is outdated or operating beyond its intended capacity.
Common older breaker systems include Federal Pacific (FPE), Zinsco, Challenger, and Pushmatic panels. These systems are frequently upgraded due to safety concerns and replacement part availability.
Learn more in our guide on Replacing FPE, Zinsco, and Challenger Breakers.
If your breakers trip frequently, your panel is full, or your electrical needs have increased significantly, it may be time for a panel upgrade.
Modern homes often require additional capacity for HVAC systems, electric vehicle chargers, home offices, and other high-demand electrical equipment.
Learn more in our guide on When to Upgrade Your Electrical Panel.
Electrical Supplies Unlimited carries a large inventory of new, used, surplus, and obsolete circuit breakers for residential, commercial, and industrial applications. We stock products from many major manufacturers and can help locate difficult-to-find replacement breakers.
Whether you need a standard residential breaker, specialty commercial breaker, or replacement for an older electrical panel, our experienced staff can help you find the right solution.

Electrical Supplies Unlimited (ESU) is your trusted source for Circuit Breakers in the Golden Triangle are of San Diego, serving contractors, electricians, property managers, and homeowners throughout the Golden Traingle area and surrounding communities including University City, 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.
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.
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.
In addition to circuit breakers, ESU stocks a large inventory of:
We also offer Greenlee tool rentals, conduit benders, wire pullers, and additional electrician equipment for contractors throughout San Diego County.
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:
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.
We proudly provide circuit breakers and electrical supplies throughout:
We also ship many products nationwide for customers outside the San Diego region.
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.
Knowing when and how to perform a circuit breaker replacement is important for maintaining a safe and reliable electrical system. Whether you are replacing a faulty breaker, upgrading an older electrical panel, or installing new equipment, choosing the correct replacement breaker helps protect wiring, appliances, and electrical devices from overloads and short circuits.
This guide explains common signs of breaker failure, how to identify the correct replacement, and important factors to consider before installing a new circuit breaker.
When Should a Circuit Breaker Be Replaced?Circuit breakers are designed to last for many years, but they can eventually wear out or become damaged. A breaker that no longer functions properly may fail to trip during an overload, creating a serious safety hazard.
Common signs that indicate a breaker may need replacement include frequent tripping, burning odors near the panel, visible damage, overheating, or a breaker that will not reset.
If you are experiencing these issues, read our guide on Signs of a Bad Circuit Breaker.
Before replacing a breaker, it is important to determine whether the breaker itself is defective or if another electrical issue is causing the problem.
Overloaded circuits, short circuits, damaged wiring, and faulty appliances can all cause breakers to trip. Simply replacing the breaker without correcting the underlying issue may not solve the problem.
Not all circuit breakers are interchangeable. Replacement breakers must be compatible with the specific electrical panel in which they are installed.
Major panel and breaker manufacturers include Siemens, Square D, Eaton, Cutler Hammer, General Electric (GE), Federal Pacific (FPE), Challenger, Pushmatic, and Zinsco. Always verify compatibility before purchasing a replacement breaker.
For additional guidance, visit our How to Choose the Right Circuit Breaker resource.
Replacement breakers must have the proper amperage rating for the circuit they protect. Installing an oversized breaker can allow wiring to overheat, while an undersized breaker may trip unnecessarily.
Common residential breaker sizes include:
The replacement breaker should match both the circuit requirements and conductor size.
Many property owners replace circuit breakers for one of the following reasons:
Older Federal Pacific (FPE), Challenger, and Zinsco breakers are commonly replaced during electrical upgrades due to safety concerns and limited availability.
Learn more in our guide on Replacing FPE, Zinsco, and Challenger Breakers.
In some situations, replacing a single breaker may not be enough. Older panels that are overloaded or lack capacity for modern electrical demands may benefit from a complete panel upgrade.
If your panel is full, you may also be considering options such as Tandem Circuit Breakers or adding additional circuits.
Learn more about upgrade considerations in our guide on When to Upgrade Your Electrical Panel.
The cost of replacing a circuit breaker depends on several factors, including breaker type, amperage, panel manufacturer, and labor requirements. Specialty and obsolete breakers may cost more than standard residential breakers.
If a larger electrical upgrade is needed, review our resource on Circuit Breaker Panel Upgrade Cost.
Electrical Supplies Unlimited carries a large inventory of new, used, surplus, and obsolete circuit breakers for residential, commercial, and industrial applications. We stock breakers from many leading manufacturers and can help locate hard-to-find replacement breakers for older electrical systems.
Whether you need a standard residential breaker or a specialty industrial breaker, our experienced staff can help identify the correct replacement.