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 voltages of circuit breakers and 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 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 are circuit breakers and electrical hardware experts and have decaades of experience to help you. Do not hesitate to call us at 858.558.2850 to find out which Circuit Breaker is right for your requirement.

used circuit breaker sales San DiegoElectrical Supplies Unlimited is your company's business source for testing, repairing, rebuilding or reconditioning electrical equipment. ESU maintains a wide variety of out of stock circuit breakers, relays, transformers, switches, relays, motor controls, and other electrical equipment. ESU will also purchase your excess electrical inventory. We also buy new and used transformers. Call us today to find out more. Some merchandise may be available as used or surplus, just call one of our representatives to find out more!

A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow. Unlike a fuse, which operates once and then has to be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation. Circuit breakers are made in varying sizes, from small devices that protect an individual household appliance up to large switchgear designed to protect high voltage circuits feeding an entire city.

Electrical Supplies Unlimited supplies a large stock of Low Voltage Circuit Breakers (600 Volts) and Medium Voltage Circuit Breakers (5-27kV).

We stock the following manufacturers products and can either provide you the circuit breaker in question or help you find it:

Low Voltage Breakers

Federal Pacific
Square D
Roller Smith
GE - General Electric
Westinghouse-Cutler-Hammer
Siemens-Allis Chalmers
ABB-BBC-ITE-Gould


Medium Voltage Breakers

GE
Westinghouse-Cutler-Hammer
Siemens-Allis Chalmers
ABB-BBC-ITE-Gould
Federal Pacific
Square D

Circuit breakers are electrical switches designed to protect an electrical circuit from damage caused by overload or short circuit.
If a circumstance arises where a fault condition occurs, the switch discontinues electrical flow. This circuit breaker can be reset either manually or automatically. In contrast, a fuse must be replaced when it operates one time.

Circuit breakers are made in varying sizes, from small devices that protect an individual household appliance up to large switchgear
designed to protect high voltage circuits feeding an entire city.

Types of Circuit Breakers

Low voltage circuit breakers
Magnetic circuit breakers
Thermal magnetic circuit breakers
Common trip breakers
Medium-voltage circuit breakers
High-voltage circuit breakers

Operation

All circuit breakers have common features in their operation, although details vary substantially depending on the voltage class, current rating and type of the circuit breaker.

The circuit breaker must detect a fault condition; in low-voltage circuit breakers this is usually done within the breaker enclosure. Circuit breakers for large currents or high voltages are usually arranged with pilot devices to sense a fault current and to operate the trip opening mechanism. The trip solenoid that releases the latch is usually energized by a separate battery, although some high-voltage circuit breakers are self-contained with current transformers, protection relays, and an internal control power source.

The simplest circuit protection device is the fuse. A fuse is just a thin wire, enclosed in a casing, that plugs into the circuit. When a circuit is closed, all charge flows through the fuse wire -- the fuse experiences the same current as any other point along the circuit. The fuse is designed to disintegrate when it heats up above a certain level -- if the current climbs too high, it burns up the wire. Destroying the fuse opens the circuit before the excess current can damage the building wiring.

The problem with fuses is they only work once. Every time you blow a fuse, you have to replace it with a new one. A circuit breaker does the same thing as a fuse -- it opens a circuit as soon as current climbs to unsafe levels -- but you can use it over and over again.

The basic circuit breaker consists of a simple switch, connected to either a bimetallic strip or an electromagnet. The diagram below shows a typical electromagnet design.
 

cutler hammer circuit breakerWe have everything from a single pole 15A 120/240V through 3 pole 3000Amp 600V in the Cutler Hammer line.

Harry Henderson Cutler and Edward West Hammer incorporate the Cutler-Hammer Manufacturing Co. in 1893, specializing in electric starters, speed regulators and field rheostats. Developed first automatic motor starter patented by Cutler in 1900, laying the foundation for the modern motor control industry, and in 1901 the company designed the control equipment for the Panama Canal.    By the 1930s, engineers at Cutler-Hammer had obtained 28 patents for the use of vacuum tubes to control heavy currents. Cutler-Hammer became part of Eaton Corporation in 1978 bringing over $500 million in sales of a complete portfolio of power control and switching devices

siemens circuit breakerESU carries a wide stock of ITE Siemens Circuit Breaekrs. We have everything from a single pole 15A 120/240 through 3 pole 3000 Amp 600V in the ITE Siemes line.

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.

 

circuit breaker

Pushmatic Circuit Breakers are in stock at ESU. We have single pole 15Amp - 40Amp and 2 pole 15Amp-100A all 120/240 double-pole circuit breakers that fit Pushmatic® load centers. It operates at 120/240 VAC.

square-d-circuit-breaker Square D Electrical Supplies Switchgear, Contactors and Motor Starters. One of the largest electrical manufacturers.

ESU carries a large and diverse inventory of Square D products, including  Circuit Breakers, Transformers, Meter Sections, Disconnects, Panel Board Switches, Switchgear, Contactors and Motor Starters. Contact one of our representatives today at 858.558.2850 to find out more!

Square D is an American manufacturer of equipment used to control and distribute electric power. They are headquartered in Palatine, Illinois.

Square D was founded in 1903 in Detroit, Michigan by Bryson Dexter Horton who is credited with the invention of the safety switch which encased high voltage switches and started the company's main line of business of circuit breakers and encased control panels.

We carry a large and diverse inventory of Square D products, including  Circuit Breakers, Transformers, Meter Sections, Disconnects, Panel Board Switches, Switchgear, Contactors and Motor Starters. Contact one of our representatives today at 858.558.2850 to find out more!

 

If your home was built between 1950 and 1990 and is equipped with a Federal Pacific Electric (FPE) circuit breaker panel with Stab-Lok circuit breakers, you run a significant risk of breaker malfunction and fire.

The breakers inside the panel are designed to guard your home against serious electrical problems by preventing circuit overload, short circuits and outside power surges coming into the panel. When an overload occurs, a breaker protects you by tripping, thus shutting down the power to the circuit. However, if a breaker is defective or not operating properly, the risk of fire to the panel and consequently to your home becomes imminent.

Why are Federal Pacific breaker boxes dangerous?

Multiple tests done on the breakers since the 1980s have proven that one in four Stab-Lok breakers are defective and will not properly trip off. Unfortunately, when the testing began in the early 1980s, a New Jersey court later ruled that FPE committed testing fraud and a cover-up, labeling the breakers as meeting the standards set by the UL when in reality, they were defective.

In 1983, the Consumer Product Safety Commission closed its two-year investigation and felt it impossible to create a product recall at the time because of budget issues, even as Federal Pacific panels and breakers continued to be installed in millions of homes that to this day still run the risk of an electrical fire. An estimated 2,800 fires each year directly result from Federal Pacific panel breaker malfunction. Federal Pacific Electric has been out of business for many years, but the danger and damage caused by their negligence continues.

Do you have a Federal Pacific panel?

If you own a home between 25 and 65 years old, check your breaker box. A Federal Pacific panel will usually have its name or logo on the front cover. Inside, you will find the name Stab-Lok printed near the center or side of the panel. The intact breakers will have the signature red strip that runs across the front.

If you find you a Federal Pacific panel or Stab-Lok breakers, or are not sure, call ESU, Inc. for further information about replacing your circuit breaker panel.

square-d-circuit-breaker Eaton Cutler-Hammer offers quality power management solutions for professionals in the aerospace, hydraulics, electrical, automotive, filtration and industrial sectors.

Key solutions from Eaton Cutler-Hammer include Industrial Control for NEMA starters and contactors, NEMA pushbutton switches, terminal blocks, relays and circuit breakers. Eaton Cutler-Hammer offers photoelectric and proximity sensors, limit switches, PLCs, HMIs, ethernet connectivity, IEC and NEMA contactors, power supplies, 22mm IEC and 30mm NEMA pushbuttons & tactile switches, toggle switches, thermal magnetic circuit breakers, rocker switches, panel meters, counters, timers and other panel instrumentation.