ESU carries a wide stock of Siemens Circuit Breakers for ITE Breaker replacements. We have everything from a single pole 15A 120/240 through 3 pole 3000 Amp 600V in the Siemens ITE line. Siemens makes new circuit breakers that can replace the old ITE breakers. The new Siemens breakers will either have the same ITE part number, or its own Siemens part number.

Siemens Corporation is a U.S. subsidiary of Siemens AG, a global powerhouse in electronics and electrical engineering, operating in the industry, energy, healthcare, and infrastructure & cities sectors. For more than 165 years, Siemens has built a reputation for leading-edge innovation and the quality of its products, services and solutions.

Siemens and ITE Circuit Breakers

In 1983 Siemens bought ITE (formerly known as Gould), a large electrical distribution company, so if you're looking to replace an ITE product, chances are you'll find exactly what you need from Siemens.  

Despite the fact they're now, technically, Siemens breakers, many loyal customers still refer to them by the ITE name.

Are you an electrician or homeowner searching for a reliable source of electrical supplies, specifically ITE breakers? Look no further than Electrical Supplies Unlimited (ESU). As a trusted provider, ESU specializes in buying, selling, and stocking a diverse range of electrical components, including Siemens Circuit Breakers ideal for ITE breaker replacements. With a wide inventory of new, surplus, and recycled items, ESU ensures that both professionals and homeowners have access to high-quality products at competitive prices. Whether you're upgrading your home's electrical system or completing a commercial project, trust ESU to provide the ITE breakers you need for reliable performance and safety. 

People also ask
Are ITE and Siemens breakers the same?

 Despite the fact they're now, technically, Siemens breakers, many loyal customers still refer to them by the ITE name

HVAC Fuses and HVAC Breakers in San Diego from ESU

At ESU Inc., we supply essential components for every project, including HVAC fuses and HVAC breakers. HVAC fuses are designed to protect heating and cooling systems by breaking the circuit if the current becomes too strong, helping prevent costly equipment damage. HVAC breakers serve a similar purpose but can be reset after tripping, providing reliable protection against electrical overloads. Whether you need standard replacements or specific models, we carry a wide selection to keep your HVAC systems running safely and efficiently.

Our inventory features most of the major brands trusted in the industry, including General Electric, Hammond Power, ITE Siemens, Cutler Hammer, Square D, FPE Federal Pacific, Pushmatic, Zinsco, Crouse Hinds, Challenger, Westinghouse, Sylvania, and Bryant. With this broad range of options and our decades of expertise, ESU Inc. is the go-to source for electrical supplies that keep your projects powered, your HVAC systems protected, and your business or home running smoothly. For more than 40 years, ESU Inc. has proudly served as a trusted name in the electrical supply industry. We carry a vast inventory of new, surplus, and recycled electrical supplies to support both commercial and residential markets. As a fully stocked Electrical Distributor and Electrical Wholesaler, we offer an extensive range of product lines and specialize in those hard-to-find items that other suppliers can’t always provide. Our knowledgeable staff is dedicated to ensuring every customer’s expectations are exceeded. Ask around—our reputation speaks for itself, or simply give us a call at 858.558.2850 and experience the ESU difference firsthand.

ESU Inc. has been a trusted electrical supply distributor for over 40 years, serving both residential and commercial markets in San Diego and surrounding areas including Miramar, Golden Triangle, Chula Vista, National City, Otay, University Height and all others in San Diego County. We carry a wide selection of new, surplus, and recycled electrical supplies, specializing in hard-to-find items.

We stock essential components like HVAC fuses—which protect heating and cooling systems by stopping overloads—and HVAC breakers, which trip and reset to keep your equipment safe. With a large inventory from top brands including General Electric, Siemens, Cutler Hammer, Square D, and more, we ensure reliable solutions for every project.

At ESU Inc., our knowledgeable team is committed to exceeding customer expectations. Call 858.558.2850 today to find the HVAC parts and electrical supplies you need from a trusted wholesaler.

Circuit Breaker Amperage Guide: Understanding Breaker Sizes and Ratings

Choosing the correct circuit breaker amperage is essential for protecting electrical wiring, equipment, and appliances from overloads and short circuits. Whether you're replacing an existing breaker, upgrading an electrical panel, or planning a new installation, understanding breaker amp ratings helps ensure safety, performance, and code compliance.

This guide explains the most common circuit breaker sizes, how amperage ratings work, and how to select the right breaker for your electrical application.

What Does Circuit Breaker Amperage Mean?

A circuit breaker's amperage rating indicates the maximum amount of electrical current the breaker can safely carry before tripping. When electrical current exceeds the breaker's rated capacity, the breaker automatically disconnects power to help prevent overheating, equipment damage, and electrical fires.

Common residential and commercial breaker sizes range from 15 amps to several hundred amps depending on the application.

15 Amp Circuit Breakers

15 amp breakers are commonly used for standard lighting circuits, bedrooms, living rooms, and general-purpose receptacles in residential applications.

These breakers typically protect 14-gauge copper wiring and are among the most frequently installed breakers in homes.

20 Amp Circuit Breakers

20 amp breakers are commonly used for kitchens, bathrooms, garages, laundry rooms, and other circuits where higher electrical loads are expected.

These breakers typically require 12-gauge copper wiring and provide additional capacity compared to 15 amp circuits.

30 Amp Circuit Breakers

30 amp breakers are often used for larger appliances and dedicated circuits, including:

• Electric dryers
• Water heaters
• Small HVAC equipment
• Specialized electrical equipment

These circuits commonly operate at 240 volts and require appropriately sized conductors.

40 Amp Circuit Breakers

40 amp breakers are frequently used for electric ranges, cooktops, HVAC systems, and larger residential electrical loads.

They are commonly found in both residential and light commercial installations.

50 Amp Circuit Breakers

50 amp breakers are often installed for:

• Electric vehicle chargers
• Large HVAC systems
• Hot tubs and spas
• Welders
• Subpanels

As electric vehicle adoption continues to grow, 50 amp breakers have become increasingly common in residential applications.

60 Amp Circuit Breakers

60 amp breakers are frequently used for subpanels, larger HVAC systems, commercial equipment, and specialized electrical installations requiring additional capacity.

They provide a reliable solution when greater electrical demand exceeds standard residential circuit requirements.

100 Amp Circuit Breakers

100 amp breakers are commonly used as service disconnects, feeder breakers, and subpanel protection devices.

Many older homes still operate on 100 amp electrical service, although modern homes often require larger capacities.

200 Amp Electrical Service

Today, 200 amp service is considered the standard for most new residential construction. A 200 amp electrical panel provides sufficient capacity for modern appliances, HVAC systems, home offices, electric vehicle chargers, and future electrical expansion.

Many homeowners upgrade older 100 amp panels to 200 amp service to accommodate increasing electrical demands.

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

How to Determine What Size Breaker You Need

Several factors influence the proper breaker size for a circuit:

• Electrical load requirements
• Wire size and conductor type
• Voltage requirements
• Continuous versus intermittent loads
• Equipment manufacturer specifications
• Local electrical code requirements

Installing an oversized breaker can create safety hazards, while undersized breakers may trip unnecessarily.

For additional guidance, visit our How to Choose the Right Circuit Breaker resource.

Common Circuit Breaker Types Available

In addition to different amperage ratings, breakers are available in several configurations:

• Single-pole breakers
• Double-pole breakers
• Tandem circuit breakers
• GFCI circuit breakers
• AFCI circuit breakers
• Commercial and industrial breakers

Each breaker type serves a specific purpose depending on the electrical application.

Learn more about Tandem Circuit Breakers and GFCI Circuit Breakers.

Replacing Circuit Breakers

If a breaker is damaged, repeatedly tripping, or no longer functioning properly, replacement may be necessary. It is important to select a replacement breaker with the correct amperage rating and panel compatibility.

Read our complete Circuit Breaker Replacement Guide for additional information.

Finding Circuit Breakers in San Diego

Electrical Supplies Unlimited carries a large inventory of new, used, surplus, and obsolete circuit breakers in a wide range of amperages and configurations. We stock products from many leading manufacturers including Siemens, Square D, Eaton, Cutler Hammer, General Electric, Federal Pacific (FPE), Challenger, Pushmatic, and more.

Whether you need a 15 amp residential breaker or a large commercial power distribution breaker, our experienced team can help you locate the correct solution.

More Circuit Breaker Resources

• Circuit Breaker Resource Hub
• Circuit Breakers San Diego
• How to Choose the Right Circuit Breaker
• Electrical Panels and Circuit Breakers
• Circuit Breaker Replacement Guide
• When to Upgrade Your Electrical Panel
• Buy Circuit Breakers San Diego

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

Electrical Supplies Unlimited buys and sells new & used Circuit Breakers in Linda Vista and San Diego surrounding areas including , Mira Mesa, 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.

Electrical Supplies Unlimited (ESU) is your trusted partner for all your electrical supply needs in the Linda Vista area of San Diego. We stand as a premier buyer of a wide range of electrical components, including transformers, breakers, fuses, and more – both new and used. Our commitment to excellence extends to every aspect of our business, ensuring that we provide the highest quality products to our customers. Whether you're looking to sell surplus electrical equipment or searching for specific components, ESU is here to streamline the process, offering competitive pricing and a seamless experience. With a reputation built on reliability and a dedication to customer satisfaction, ESU is the go-to source for all your electrical supply requirements in Bay Ho and beyond. Contact us today to explore how we can assist you with your electrical supply needs

Welcome to ESU, your trusted partner for all your circuit breaker needs in Linda Vista, San Diego. We specialize in buying new, used, and surplus circuit breakers, providing a streamlined solution for individuals and businesses looking to optimize their electrical systems. With a focus on sustainability and cost-efficiency, ESU offers a unique opportunity to turn your surplus or unused circuit breakers into value. Our expert team assesses each circuit breaker to ensure it meets our high standards of quality and safety, ensuring you receive a fair and competitive offer. Whether you're upgrading your electrical infrastructure or simply have surplus inventory, ESU is here to provide a hassle-free way to sell your circuit breakers while contributing to a more sustainable future. Contact us today to discover how ESU can help you unlock the potential of your circuit breakers.

ESU Inc has been in the electrical supply business for over 40 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 Linda Vista, Bay Ho, 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!