Circuit Breakers in Kearney Mesa San Diego – New & Used Breakers, Panels & Electrical Supplies

Electrical 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.

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 Kearney Mesa & Greater San Diego

We proudly provide circuit breakers and electrical supplies throughout:

• La Jolla
• Del Mar
• Cardiff
• Encinitas
• 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.

Thermal Magnetic Circuit Breakers

Thermal magnetic circuit breakers are one of the most widely used types of circuit protection in residential, commercial, and industrial electrical systems. They combine two separate protection mechanisms—thermal protection for overloads and magnetic protection for short circuits—making them highly reliable and efficient.

These breakers are commonly found in modern electrical panels and are essential for protecting wiring, appliances, and electrical systems from damage caused by excessive current.

How Thermal Magnetic Circuit Breakers Work

Thermal magnetic circuit breakers use a dual protection system:

• Thermal element: Responds to sustained overloads by heating a bimetal strip that trips the breaker.
• Magnetic element: Responds instantly to short circuits using electromagnetic force to trip the breaker.

This combination allows the breaker to protect against both slow-building overloads and sudden electrical faults.

Where Thermal Magnetic Breakers Are Used

These breakers are standard in many electrical applications, including:

• Residential electrical panels
• Commercial buildings
• Industrial equipment
• HVAC systems
• Motor control circuits

In San Diego, they are commonly used in both new construction and panel upgrades to meet modern electrical code requirements.

Benefits of Thermal Magnetic Circuit Breakers

• Dual protection against overloads and short circuits
• Reliable and long-lasting performance
• Widely available and cost-effective
• Compatible with most modern electrical panels

Thermal Magnetic vs Other Circuit Breakers

Unlike specialty breakers such as AFCI or GFCI breakers, thermal magnetic breakers focus on core electrical protection. They do not provide arc-fault or ground-fault protection but are essential as the primary layer of circuit safety.

Learn more about other breaker types in our guide on circuit breaker types and applications.

When to Replace a Thermal Magnetic Circuit Breaker

You may need to replace a breaker if you notice:

• Frequent tripping under normal load
• Physical damage or burn marks
• Breaker fails to reset properly
• Outdated or incompatible panel systems

If your breaker is frequently tripping, visit our guide on why circuit breakers keep tripping.

Used in San Diego Electrical Systems

Thermal magnetic circuit breakers are commonly used throughout San Diego homes and businesses due to their reliability and compliance with electrical code standards.

They are often installed during:

• Panel upgrades
• New construction projects
• Electrical system repairs
• Equipment replacements

For local electrical solutions, visit our main page on circuit breakers in San Diego.

Related Circuit Breaker Resources

• How to Choose the Right Circuit Breaker
• Circuit Breaker Panel Upgrade Cost
• Tandem Circuit Breakers
• How Many Breakers Can Be in a Panel

Circuit Breaker Resources & Guides!

Welcome to ESU’s Circuit Breaker Resources Hub — your ultimate guide to understanding, selecting, and maintaining circuit breakers for residential, commercial, and industrial applications. Whether you’re an electrician, contractor, or a homeowner looking to upgrade your electrical panel, this hub provides authoritative guides, brand comparisons, safety tips, and troubleshooting advice to help you make informed decisions.

Why Understanding Circuit Breakers Matters

Circuit breakers are the heart of any electrical system. They protect your home, business, or industrial facility from electrical overloads and short circuits, preventing fires and costly equipment damage. Selecting the right circuit breaker is essential for safety, compliance, and long-term reliability.

Our resources cover all aspects of circuit breakers, from low voltage residential breakers to medium voltage industrial solutions, and help you navigate the many brands, types, and technical specifications available.

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!

When to Upgrade Your Electrical Panel

If your panel is outdated or overloaded, upgrading may be the safest solution. Many San Diego homeowners upgrade to support modern appliances, HVAC systems, and EV chargers. 

When to Upgrade Your Electrical Panel

Knowing when to upgrade your electrical panel is essential for maintaining a safe and reliable electrical system. As homes add more appliances, HVAC systems, and modern technology, older panels often struggle to keep up with increased electrical demand.

If your panel is outdated or showing warning signs, upgrading your electrical panel can improve safety, prevent power issues, and support future electrical needs.

Signs You Need to Upgrade Your Electrical Panel

1. Frequent Circuit Breaker Trips

If your breakers trip regularly, it may be a sign that your panel is overloaded or unable to handle current electrical demand. Learn more about this issue in our guide on why circuit breakers keep tripping.

2. Your Panel Is Out of Space

If your panel has no room for additional circuits, you may be tempted to use tandem circuit breakers. While this can work in some cases, it is often a sign that a full panel upgrade is the better long-term solution.

3. You Have an Older or Outdated Panel

Older electrical panels may not meet current safety standards and may not provide reliable protection. Some outdated breaker systems are known to have safety concerns and should be evaluated for replacement.

4. Flickering or Dimming Lights

Lights that flicker or dim when appliances turn on may indicate that your panel cannot handle the electrical load. This is a common sign that your system needs an upgrade.

5. Adding New Appliances or Equipment

Installing new appliances such as HVAC systems, electric vehicle chargers, or kitchen equipment increases electrical demand. Many older panels are not designed to support these upgrades.

6. You’re Planning a Home Remodel or Addition

Home renovations often require additional circuits and increased electrical capacity. Upgrading your panel ensures your system can safely support new wiring and equipment.

Benefits of Upgrading Your Electrical Panel

Upgrading your panel provides several important advantages:

• Improved electrical safety
• Reduced risk of overloaded circuits
• Increased capacity for modern appliances
• Better system reliability
• Support for future upgrades such as solar or EV charging

What Size Panel Do You Need?

Most modern homes upgrade to a 200-amp electrical panel to handle current and future electrical needs. The right panel size depends on your home’s electrical usage, number of circuits, and planned upgrades.

If you are unsure how many circuits your panel can support, read our guide on how many breakers can be in a panel.

Cost of Upgrading an Electrical Panel

The cost of upgrading an electrical panel varies based on the size of the panel, labor requirements, and additional electrical work needed. Most residential upgrades fall within a predictable range.

For a detailed breakdown, visit our guide to circuit breaker panel upgrade cost.

Choosing the Right Circuit Breakers

When upgrading your panel, selecting the correct breakers is critical for safety and performance. Breakers must match your panel type and electrical requirements.

Learn more in our guide on how to choose the right circuit breaker.

Explore More Circuit Breaker Resources

For more information about circuit breaker types, troubleshooting, and electrical safety, visit our Circuit Breaker Resource Hub.

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