Circuit breakers are responsible for halting the flow of electricity in case of overload or fault. They are used in almost all electrical systems. These devices detect overloaded circuits by observing current draw and temperature and if necessary they will interrupt the power supply by snapping two metal pieces apart.

Purchasing Used Circuit Breakers

Purchasing used circuit breakers is an excellent way to save money while still getting the quality you need for your electrical systems. These devices are disassembled, cleaned, and inspected to ensure they meet industry standards. However, they do come with some risks, so it’s important to buy from a trusted supplier. circuit breaker for sale at surplusrecord.

If you’re looking for a specific type of circuit breaker, it’s important to know the manufacturer and catalog number. Then, you can use this information to find the exact replacement. In addition, if the breaker is colocated in a panel with other breakers with similar markings, you can also reference those markings to determine the type of breaker you need.

One of the most common types of molded  circuit breakers is the LAL36400. This device has a voltage of 600 volts and an amperage of 400 with three poles. It also has thermal-magnetic trip technology. This product is available for purchase from a re-certified seller for $1,180 with a one-year warranty included.

Another option is the GJL36020 molded circuit breaker. This device has a voltage of 6000 volts and an amperage of 20 with three poles. It also has thermal-magnetic and instantaneous trip technology. This product is available from a re-certified seller for $479 with a one-year warranty included. These types of molded breakers are sometimes called drawout circuit breakers. This is because they have a base that bolts to the frame of an electrical system and insulated parts that are electrically connected to the base. They’re typically mounted with a trolley-type of hoist that facilitates “racking in” (installation) and “racking out” (withdrawal).

Molded Breakers and short circuits

Designed to protect electrical circuits against short circuits, current overloads and other power anomalies, molded circuit breakers install contacts, arc extinguishing chambers and trippers inside a plastic case. These devices are typically low-maintenance and easy to use. They are available in both AC and DC models. The rated control power supply voltage and the rated limit short-circuit breaking capacity are important factors to consider when purchasing a breaker for any specific purpose.

A molded circuit breaker (MCCB) is different from traditional circuit breakers because it’s an industrial-grade device that can handle higher currents and longer durations of abnormal currents. It’s a type of overload protection device that can be found in many types of systems, including industrial ones and solar energy power systems.

MCCBs are categorized into various types based on their release or tripping curves. For example, a type B MCCB is designed to trip when it detects currents 3-5 times its rating within 0.04-13 seconds. These devices are best for resistive loads like lighting and heating.

In contrast, type C MCCBs are designed to handle up to 10x their ratings before tripping. They show moderate sensitivity to both overloads and short circuits, making them ideal for industrial settings with motors. Then there’s type K MCCBs, which push the limits further by detecting currents up to 20x its ratings and trip in about 0.04-5 seconds.

Vacuum Circuit Breakers the current interrupter

Vacuum circuit breakers are a type of electrical current interrupter that uses vacuum as an insulating medium. They have an extremely high arc quenching strength, which makes them ideal for medium voltage applications. This is primarily due to the fact that vacuum has more dielectric strength than air or SF6 gas. This is what allows them to easily interrupt current in a short amount of time.

The arc that is produced in a vacuum circuit breaker is quickly quenched because of the metal vapor ionization and electron emission that takes place inside the contacts. This helps to eliminate contact erosion. They also have a narrower gap between the moving and stationary contacts, which helps to reduce the risk of overheating.

Another feature that sets vacuum breakers apart from other air circuit breakers is the ability to handle intense recovery transients. This is especially useful for fault clearing. VCBs can easily handle short line faults and faults near transformers. They also have a long endurance rating, which means they can be used for thousands of actions at their full short-circuit rating.

Because of their unique arc interruption method, vacuum circuit breakers are more efficient and require less maintenance than other types of circuit breakers. This makes them ideal for power distribution systems. They also work well as a protective device for transmission lines.

Air Circuit Breakers mounted in load centres

For use in electrical systems up to 132 kV and with breaking capacities up to 7000 MVA. These circuit breakers are mounted in loadcenters and breaker panels. They have air break contacts and are powered by an electro-magnetic trip coil that is energized when power passes through the contact terminals. This causes the closing spring to be compressed and the mechanical latch on the operating handle to move to the open position. Re-closing the breaker is accomplished by manually moving the operating handle to the closed position.

Depending upon the manufacture of each breaker a variety of indicator lamps provide the user with an indication of what type of event caused the breaker to trip. These include long time, short time and instantaneous fault. In addition some breakers can be equipped with data display features including voltmeters, current meters and waveform displays.

When a fault occurs in an electrical system it will build heat in a thermal element within the breaker. As the heat builds up the BI-metal element will bow and this will cause the operating handle to move to the open position. This is what trips the breaker. Some manufacturers are designing their breakers to offer an ambient compensation function that will eliminate the need for the user to adjust the breaker's trip point based upon the temperature of its environment.