ESU buys and sells new & used Circuit Breakers, Fuses, Switches, Plugs and more for Del Mar, San Diego

Electrical Supplies Unlimited buys and sells new & used Circuit Breakers in Del Mar and San Diego surrounding areas including Carmel Valley, La Jolla, Pacific Beach, Clairemont, University City, Sorrento Valley and many more. Of course, we can arrange shipment on a wide variety of products to service those outside our area. We will also buy your used Transformers.

ESU Inc has been in the electrical supply business for over 30 years. We have a large inventory of new, surplus and recycled electrical supplies both for the commercial and residential markets. We are a fully stocked Electrical Distributor and Electrical Wholesaler with many different lines in stock. We specialize in  hard to find items. Our staff is very knowledgeable and our mission is to ensure that our customers expectations are exceeded. Ask around, our reputation is what makes us! Or just call to find out yourself at 858.558.2850.

We stock most major brands including 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 buys and sells new and used Circuit Breakers and more for Del Mar, San Diego County and surrounding areas including Carmel Valley, Sorrento Valley, La Jolla, University City and more. Of course, we can arrange shipment on a wide variety of products to service those outside our area. We will also purchase your used Transformers.

We purchase most major brands including Acme, Westinghouse, Cutler Hammer, ITE Siemens, FPE  Federal Pacific, Square D, General Electric and Zinsco products. We are a fully stocked Electrical Distributor and Electrical Wholesaler with many different lines in stock.

Circuit Breakers Electrical Supplies Unlimited is your go-to source for Circuit Breaker electrical supplies in San Diego and surrounding areas. We have a large inventory of most brands of circuit breakers including most amperages and voltages. We carry a large variety of manufacturers, including Zinsco, Federal Pacific FPE, Pushmatic, Bulldog, Cutler, Hammer, ITE Siemens, Square D etc. in our San Diego store. We carry most amperages and voltages. Some examples of what we carry:

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!

How Many Breakers Can Be in a Panel?

One of the most common questions homeowners and contractors ask is how many breakers can be in a panel. The answer depends on the panel’s design, electrical capacity, and manufacturer specifications—not just the physical number of breaker slots.

Understanding breaker limits is important for maintaining a safe electrical system and avoiding overloaded panels or code violations.

Breaker Limits Are Based on Panel Rating

Every electrical panel is designed with a maximum number of circuits it can safely support. This limit is determined by the panel manufacturer and is clearly listed on the panel label.

For example, a panel may be rated for 20, 30, or 40 circuits depending on its size and configuration. Even if additional breakers physically fit, exceeding the rated number of circuits can create safety risks.

What Is the Difference Between Slots and Circuits?

It’s important to understand the difference between breaker slots and circuits:

• Slots: Physical spaces in the panel for breakers
• Circuits: Individual electrical lines protected by breakers

Some panels allow more circuits than slots by using tandem circuit breakers, which fit two circuits into a single slot.

Using Tandem Breakers to Add Circuits

Tandem breakers can increase the number of circuits in a panel without expanding its size. However, they are only allowed in panels that are specifically designed to accept them.

Installing tandem breakers in the wrong panel or exceeding the allowed number of circuits can lead to overheating, code violations, and potential electrical hazards.

Learn more about how these work in our guide to tandem circuit breakers.

Typical Breaker Capacity by Panel Size

While exact limits vary by manufacturer, here are common examples:

• 100-amp panel: typically 20–30 circuits
• 150-amp panel: typically 30–40 circuits
• 200-amp panel: typically 40–60 circuits

Always refer to the panel label to confirm the exact circuit limit for your system.

What Happens If You Exceed Panel Capacity?

Adding too many breakers beyond the panel’s rating can result in:

• Overheating of the electrical panel
• Increased risk of electrical fires
• Code violations during inspections
• Unreliable circuit performance

If your panel is already at capacity, adding more circuits without upgrading the panel is not recommended.

When to Upgrade Your Electrical Panel

If you need more circuits than your panel allows, it may be time for an upgrade. This is especially common during:

• Home remodels or additions
• Installing new appliances or HVAC systems
• Adding EV chargers or solar systems
• Replacing outdated electrical panels

Upgrading your panel provides more capacity and improves overall electrical safety.

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

Choosing the Right Circuit Breakers

Using the correct breaker type and brand is essential for maintaining safe operation. Breakers must be compatible with your panel 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

To learn more about breaker types, troubleshooting, and electrical safety, visit our Circuit Breaker Resource Hub.

ESU buys and sells new & used Circuit Breakers, Fuses, Switches, Plugs and more for Carmel Valley, San Diego

Electrical Supplies Unlimited buys and sells new & used Circuit Breakers in Carmel Valley and San Diego surrounding areas including La Jolla, Pacific Beach, Miramar, University City, Sorrento Valley and many more. Of course, we can arrange shipment on a wide variety of products to service those outside our area. We will also buy your used Transformers.

ESU Inc has been in the electrical supply business for over 30 years. We have a large inventory of new, surplus and recycled electrical supplies both for the commercial and residential markets. We are a fully stocked Electrical Distributor and Electrical Wholesaler with many different lines in stock. We specialize in  hard to find items. Our staff is very knowledgeable and our mission is to ensure that our customers expectations are exceeded. Ask around, our reputation is what makes us! Or just call to find out yourself at 858.558.2850.

We stock most major brands including 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 buys and sells new and used Circuit Breakers and more for Carmel Valley, San Diego County and surrounding areas including Sorrento Valley, La Jolla, Miramar, Miramar, Carmel Valley, University City and more. Of course, we can arrange shipment on a wide variety of products to service those outside our area. We will also purchase your used Transformers.

We purchase most major brands including Acme, Westinghouse, Cutler Hammer, ITE Siemens, FPE  Federal Pacific, Square D, General Electric and Zinsco products. We are a fully stocked Electrical Distributor and Electrical Wholesaler with many different lines in stock.

Circuit Breakers Electrical Supplies Unlimited is your go-to source for Circuit Breaker electrical supplies in San Diego and surrounding areas. We have a large inventory of most brands of circuit breakers including most amperages and voltages. We carry a large variety of manufacturers, including Zinsco, Federal Pacific FPE, Pushmatic, Bulldog, Cutler, Hammer, ITE Siemens, Square D etc. in our San Diego store. We carry most amperages and voltages. Some examples of what we carry:

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!

ESU buys and sells new & used Circuit Breakers, Fuses, Switches, Plugs and more for Tierrasanta, San Diego

Electrical Supplies Unlimited buys and sells new & used Circuit Breakers in Tierrasanta and San Diego surrounding areas including Carmel Valley, La Jolla, Pacific Beach, Clairemont, University City, Sorrento Valley and many more. Of course, we can arrange shipment on a wide variety of products to service those outside our area. We will also buy your used Transformers.

ESU Inc has been in the electrical supply business for over 30 years. We have a large inventory of new, surplus and recycled electrical supplies both for the commercial and residential markets. We are a fully stocked Electrical Distributor and Electrical Wholesaler with many different lines in stock. We specialize in  hard to find items. Our staff is very knowledgeable and our mission is to ensure that our customers expectations are exceeded. Ask around, our reputation is what makes us! Or just call to find out yourself at 858.558.2850.

We stock most major brands including 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 buys and sells new and used Circuit Breakers and more for Tierrasanta, San Diego County and surrounding areas including Carmel Valley, Sorrento Valley, La Jolla, University City and more. Of course, we can arrange shipment on a wide variety of products to service those outside our area. We will also purchase your used Transformers.

We purchase most major brands including Acme, Westinghouse, Cutler Hammer, ITE Siemens, FPE  Federal Pacific, Square D, General Electric and Zinsco products. We are a fully stocked Electrical Distributor and Electrical Wholesaler with many different lines in stock.

Circuit Breakers Electrical Supplies Unlimited is your go-to source for Circuit Breaker electrical supplies in San Diego and surrounding areas. We have a large inventory of most brands of circuit breakers including most amperages and voltages. We carry a large variety of manufacturers, including Zinsco, Federal Pacific FPE, Pushmatic, Bulldog, Cutler, Hammer, ITE Siemens, Square D etc. in our San Diego store. We carry most amperages and voltages. Some examples of what we carry:

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!