3 meter

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!

 

Best Circuit Breaker Brands – Complete Comparison

Best Circuit Breaker Brands: Residential, Commercial, and Industrial

Choosing the right circuit breaker brand is essential for protecting your home, office, or industrial facility from electrical overloads and short circuits. With many brands available, it’s important to understand the differences in reliability, performance, and compatibility before making a purchase.

In this guide, we compare the best circuit breaker brands for residential, commercial, and industrial applications, helping you make an informed decision for your electrical system.

1. Square D

Square D, a brand of Schneider Electric, is one of the most recognized and widely used breaker brands in North America. Known for reliability and performance, Square D offers:

  • QO Series: Premium residential breakers with fast-trip technology
  • Homeline Series: Cost-effective residential breakers for standard panels
  • PowerPact Series: Commercial and industrial solutions

Square D breakers are widely available and offer strong compatibility with many panel types, making them a popular choice for electricians and homeowners alike.

eaton circuit breaker2. Eaton

Eaton is a leading manufacturer of circuit protection products for residential, commercial, and industrial use. Popular Eaton product lines include:

  • BR Series: Residential breakers for everyday circuits
  • CH Series: Premium residential breakers with copper bus connection
  • Series G: Industrial molded case breakers for high-power applications

Eaton breakers are praised for durability, long-term reliability, and compatibility with legacy panels.

3. Siemens

Siemens circuit breakers are known for their quality and affordability. Their residential and commercial breakers include:

  • QP Series: Residential circuit protection
  • MP Series: Industrial molded case breakers
  • Siemens also offers combination AFCI/GFCI breakers for added safety

Siemens breakers are widely used in new installations and are recognized for their easy installation and long-term performance.

4. General Electric (GE)

GE has been a trusted name in residential electrical systems for decades. Their breaker offerings include:

  • THQL Series: Standard residential breakers
  • THQC Series: Commercial and industrial breakers
  • GE breakers provide solid reliability and are compatible with many older panels

5. Challenger

Challenger breakers were popular in older residential and commercial installations but are less commonly used in new construction today. Some models have been recalled due to reliability concerns, so replacement with modern breakers is recommended when upgrading older panels.

How to Choose the Right Brand for Your System

When selecting a breaker brand, consider:

  • Panel compatibility: Use the brand recommended by your panel manufacturer
  • Load and application requirements: Residential, commercial, or industrial
  • Breaker features: AFCI, GFCI, or standard thermal-magnetic protection
  • Reliability and safety record: Avoid recalled or outdated brands such as FPE Stab-Lok, Zinsco, or certain Challenger models

Learn More About Circuit Breakers

To explore more guides on breaker selection, troubleshooting, and safety, visit our Circuit Breaker Resource Hub. Our resources help homeowners, electricians, and contractors make informed decisions when installing or replacing breakers.

Learn More About Circuit Breakers

For a complete overview of breaker types, brands, and electrical safety considerations, visit our Circuit Breaker Resource Hub where we provide expert guides for residential, commercial, and industrial electrical systems.

For a complete overview of breaker types, brands, and electrical applications, visit our Circuit Breaker Resource Hub.

More Circuit Breaker Resources

Residential Circuit Breaker Safety

Residential Circuit Breaker Safety Tips for Homeowners

Residential circuit breakers are designed to protect your home’s electrical system from dangerous overloads and short circuits. When working properly, a breaker automatically shuts off power when electrical current exceeds safe levels, preventing fires, damaged appliances, and serious electrical hazards.

Understanding residential circuit breaker safety is essential for homeowners, property managers, and electricians. Knowing how to recognize warning signs and follow basic home electrical safety tips can help prevent costly repairs and protect your family.

Why Circuit Breaker Safety Matters in Homes

Your electrical panel distributes electricity throughout your home. Each circuit breaker protects a specific circuit by stopping electrical flow when a problem occurs. Without properly functioning breakers, overloaded circuits could overheat wiring and potentially start electrical fires.

Following proper electrical panel safety practices helps ensure your system remains reliable and compliant with modern electrical standards.

Never Overload Electrical Circuits

One of the most common causes of breaker trips is circuit overload. This occurs when too many appliances draw power from the same circuit at the same time.

High-power devices such as space heaters, microwaves, hair dryers, and portable air conditioners can quickly exceed a circuit's capacity. Spreading appliances across different outlets and circuits helps prevent overload conditions.

Do Not Ignore Frequently Tripping Breakers

A breaker that trips occasionally may simply indicate temporary overload. However, breakers that trip repeatedly may signal a more serious electrical issue such as damaged wiring, faulty appliances, or a failing breaker.

If you experience frequent breaker trips, it's important to investigate the cause rather than repeatedly resetting the breaker.

Keep Your Electrical Panel Accessible

Your breaker panel should always remain easily accessible in case power needs to be shut off quickly during an emergency. Avoid blocking the panel with furniture, storage boxes, or other household items.

Electrical panels should also be clearly labeled so each breaker can be quickly identified when troubleshooting a problem.

Watch for Warning Signs of Electrical Problems

Several warning signs may indicate a circuit breaker or electrical panel issue:

  • Burning smells near the electrical panel
  • Warm or hot breaker switches
  • Flickering lights throughout the home
  • Breakers that will not stay reset
  • Buzzing or crackling sounds from the panel

If any of these symptoms occur, the breaker or wiring may require professional inspection.

Replace Outdated or Unsafe Breakers

Some older electrical panels contain breakers that are now considered unsafe or unreliable. Brands such as FPE Stab-Lok, Zinsco, and certain Challenger panels have been associated with failure to trip during electrical faults.

Replacing outdated breakers with modern, code-compliant components greatly improves residential electrical safety.

When to Call an Electrician

While homeowners can safely reset a breaker, electrical repairs and panel upgrades should always be performed by qualified professionals. Licensed electricians can diagnose wiring problems, replace faulty breakers, and ensure the system meets current electrical code requirements.

Learn More About Circuit Breakers

If you want to better understand breaker types, compatibility, and electrical system protection, explore our complete Circuit Breaker Resource Hub where we provide expert guidance for residential, commercial, and industrial applications.

For a complete overview of breaker types, brands, and electrical applications, visit our Circuit Breaker Resource Hub.

More Circuit Breaker Resources

Signs of a Bad Circuit Breaker

Signs of a Bad Circuit Breaker

Circuit breakers are designed to protect your electrical system from overloads, short circuits, and electrical faults. However, like any mechanical component, breakers can wear out over time. Recognizing the signs of a bad circuit breaker can help prevent electrical damage, appliance failure, or potential fire hazards in your home.

Most circuit breakers are designed to last many years, but heavy electrical loads, aging components, and repeated tripping can cause breakers to fail. When this happens, the breaker may no longer provide proper electrical protection.

Common Signs of a Failing Circuit Breaker

1. Breaker Trips Frequently

One of the most common signs of a failing breaker is when the circuit breaker trips frequently even when electrical demand is normal. While occasional tripping may occur during overloads, repeated tripping without an obvious cause could indicate a worn or defective breaker.

2. Breaker Will Not Reset

If a breaker immediately trips again after being reset, or refuses to stay in the “on” position, the breaker may be damaged internally. This can occur when internal components wear out or after repeated electrical faults.

3. Burning Smell from the Electrical Panel

A burning smell near the breaker panel is a serious warning sign. This may indicate overheating wires, internal breaker damage, or loose electrical connections. Any burning odor near an electrical panel should be inspected immediately.

4. Breaker Feels Hot

A circuit breaker should never feel hot to the touch. While slight warmth may occur under heavy electrical load, excessive heat can indicate a failing breaker or overloaded circuit.

5. Visible Damage or Discoloration

Physical signs such as burn marks, melted plastic, or discoloration around the breaker can indicate overheating or internal failure. These breakers should be replaced immediately to maintain electrical safety.

6. Flickering Lights or Power Fluctuations

If lights flicker or power fluctuates when appliances start or stop, it could indicate a breaker that is no longer maintaining a stable electrical connection.

Older Breaker Panels May Have Higher Failure Risk

Some older breaker panels are known to have reliability issues and may not trip properly during electrical faults. Homes with outdated breaker panels should be evaluated to ensure the electrical protection system is functioning correctly.

Upgrading older panels can significantly improve electrical safety and system reliability.

When Should a Circuit Breaker Be Replaced?

A circuit breaker should be replaced if it shows any of the following symptoms:

  • Frequent tripping without heavy electrical load
  • Breaker will not reset
  • Breaker feels hot
  • Visible burn marks or damage
  • Electrical panel buzzing or humming

Replacing a faulty breaker helps restore proper electrical protection and prevents damage to wiring and appliances.

Professional Circuit Breaker Inspection

If you notice any signs of a bad circuit breaker, it is important to have your electrical panel inspected by a qualified professional. An inspection can determine whether the issue is a simple breaker replacement, overloaded circuits, or a larger electrical panel problem.

Learn more about breaker safety in our guide to residential circuit breaker safety or read our article on how to choose the right circuit breaker.

Learn More About Circuit Breakers

To explore additional resources about circuit breaker types, safety tips, and troubleshooting, visit our Circuit Breaker Resource Hub. Our guides help electricians, contractors, and homeowners understand how to maintain safe electrical systems.

Explore Our Circuit Breaker Guides & Resources

Below is our growing library of circuit breaker guides designed to help homeowners, electricians, and contractors understand electrical safety, breaker selection, and troubleshooting.

Visit our Circuit Breaker Resource Hub to explore more information about breaker types, electrical safety, and selecting the right circuit protection for your project.

Square D vs Eaton Circuit Breakers: Which Brand Is Better?

Square D vs Eaton Circuit Breakers: Which Brand Is Better?

When selecting a circuit breaker for a residential or commercial electrical panel, two of the most commonly compared brands are Square D and Eaton. Both manufacturers produce high-quality breakers designed to protect electrical systems from overloads and short circuits. Understanding the differences between these brands can help electricians, contractors, and homeowners choose the right product for their electrical installation.

This guide compares Square D vs Eaton circuit breakers, including compatibility, reliability, pricing, and common applications.

Overview of Square D Circuit Breakers

Square D, a brand of Schneider Electric, is one of the most recognized names in electrical equipment. Square D breakers are widely used in residential homes and commercial buildings throughout North America.

The most common Square D product lines include:

  • Square D Homeline – Designed primarily for residential electrical panels
  • Square D QO – Premium breakers known for reliability and fast trip response
  • Square D PowerPact – Commercial and industrial circuit protection

Square D breakers are known for strong safety performance and wide availability in the electrical supply market.

Overview of Eaton Circuit Breakers

Eaton is another major manufacturer of electrical distribution equipment and circuit protection products. Eaton breakers are used in residential, commercial, and industrial electrical systems around the world.

Common Eaton breaker product lines include:

  • Eaton BR – Residential panel breakers
  • Eaton CH – Premium residential breakers with copper bus connection
  • Eaton Series G – Industrial molded case breakers

Eaton breakers are known for durability and compatibility with many legacy electrical panels.

Square D vs Eaton Breakers: Key Differences

Although both brands perform the same core function, several differences may influence which breaker is best for a particular electrical system.

  • Panel Compatibility: Breakers must match the panel brand and model.
  • Product Lines: Each manufacturer offers different breaker series designed for specific applications.
  • Trip Technology: Premium breakers may include faster trip detection or arc-fault protection.
  • Price Range: Costs vary depending on breaker type and amperage rating.

Because breakers are designed to work with specific electrical panels, compatibility is often the most important factor when choosing between brands.

Which Circuit Breaker Brand Is More Reliable?

Both Square D and Eaton are considered highly reliable manufacturers with strong reputations in the electrical industry. Licensed electricians commonly install products from both companies depending on the panel brand and project requirements.

Square D QO breakers are often considered one of the most reliable residential breakers available, while Eaton CH breakers are known for their copper bus design and long-term durability.

Can Square D and Eaton Breakers Be Interchanged?

In most cases, circuit breakers are not interchangeable between different panel brands. Electrical panels are designed to accept specific breaker models that match the bus bar configuration and safety certification.

Installing an incompatible breaker can create safety hazards and may violate electrical code requirements. Always verify compatibility before replacing or installing breakers.

Choosing the Right Breaker for Your Electrical Panel

The best circuit breaker for your system depends on several factors, including panel type, electrical load requirements, and safety features such as GFCI or AFCI protection.

Electricians typically recommend using the breaker brand specified by the panel manufacturer to ensure proper fit and performance.

Learn More About Circuit Breakers

For a complete overview of breaker types, brands, and electrical safety considerations, visit our Circuit Breaker Resource Hub where we provide expert guides for residential, commercial, and industrial electrical systems.

For a complete overview of breaker types, brands, and electrical applications, visit our Circuit Breaker Resource Hub.

More Circuit Breaker Resources

  1. Circuit Breaker Keeps Tripping – Causes and Fixes
  2. Circuit Breaker Resources
  3. Low Voltage Circuit Breakers: Types, Applications, and Safety
  4. Medium Voltage Circuit Breakers: Industrial Power Protection