Types of Circuit Breakers for Sale

A circuit breaker breaks current delivery by opening the electrical contacts. When the contacts are opened during a fault condition, arcs can form which produce conductive ionized gases and molten metal.

From the standard 200-amp panel in your home to large switchgear protecting power lines feeding a city, circuit breakers come in varying sizes and voltage ranges. How do you know which one to choose?

Used Circuit Breakers

Circuit breakers are electrical switchgear used circuit breakers to protect power equipment in households, commercial and industrial places from faulty current, overload, short-circuit and fire. They operate on medium voltages ranging between 1,000 and 72,000 volts. Unlike fuses, they have an operating mechanism and can be either manual or electric. The operation of the circuit breaker is done via an operating handle that can be found on its physical body and by using its bimetallic contacts. The operating handle when moved forward provides motion to the closing spring which in turn closes the circuit path for the flow of current. Circuit breaker for sale at surplusrecord.

This system can also interrupt current for a specified time during abnormal conditions such as an over-current or overload situation preventing extensive damage. The quality of a circuit breaker can be determined by its maximum current value and let-through energy. Major appliances like 5,000-watt electric water heaters and 10,000-watt electric ranges are protected by large circuit breaker sizes.

The mechanism behind the action of a circuit breaker is quite complex. When the circuit breaker detects that the current passing through it exceeds its design limits, the moving contacts are opened by the electromagnet inside the breaker panel. As the contact area is reduced and the current intensity increases, the arc between them forms. This arc is capable of melting metals and causing fires, so it needs to be broken quickly. Different type of breakers are air circuit breaker / vacuum circuit breaker/ molded circuit breaker.

Molded Breakers

If you are in the market for molded breakers, there are plenty of options on the market. These devices have the ability to handle high currents and offer protection against overloads and short circuits. They also have a trip setting that can be adjusted according to the application.

A molded case circuit breaker, or MCCB, is a device that uses a thermal mechanism to protect against overcurrents and short circuits. This mechanism uses a bimetallic contact that expands and contracts depending on the temperature. When the MCCB is exposed to an overcurrent, the contact heats up due to the increase in current density. This heating causes the contacts to separate, creating an arc between them. This arc is interrupted by a coil, which acts as an insulator and is not part of the main conducting system.

In addition to the thermal trip mechanism, a molded case circuit breaker has an operating mechanism that handles opening and closing the contacts. This switch has a handle that is moved from the center-tripped position to the off position and then back to the on position. It is important to note that a molded case circuit breaker cannot be prevented from tripping by holding the handle in the on position, as this will cause an open arc. For this reason, it is essential to learn how to read and understand the MCCB trip curve before purchasing one.

Vacuum Circuit Breakers

Vacuum circuit breakers for sale are designed to interrupt current in the case of an overload or short-circuit. They perform the same functions as minimal-oil switches but can also separate and hold current. They are typically used in medium-voltage switchgear and have a high breaking current capacity. They are capable of operating in extremely harsh environments, such as arc furnaces and metallurgical plants.

Unlike other circuit breakers, vacuum circuit breaks use a vacuum as an arc-extinguishing medium. The vacuum acts as an insulator and doesn’t allow electricity to pass through it, so the arc is easily extinguished. Vacuum breakers are also highly reliable and have a longer operating life than other types of circuit breakers.

The operation of current-carrying contacts and arc interruption takes place in the arc chamber inside the breaker, which includes steel arc shields positioned within the center of symmetrically placed ceramic insulators. The arc chamber is filled with a mixture of vacuum and SF6 gas. The SF6 is a non-flammable and inert gas that has a high electronegative charge. It acts as an insulator by absorbing the free electrons that cause an arc during opening of the current-carrying contact. Different type of breakers are air circuit breaker / vacuum circuit breaker/ molded circuit breaker

The vacuum in the arc chamber is maintained at 10-2 torr or 10-6 bar. When the breaker’s vacuum is lost, it will no longer function properly and can only be restored by reopening it in the presence of a suitable insulator.

Air Circuit Breakers

Air circuit breakers for sale are designed to protect electric power lines from current overload and short-circuiting. They are also able to interrupt arcs by using a high-velocity air blast to quench the arc created when the electrical contacts open to interrupt a current. They are a common device found in electrical switches, switchgear and indoor medium voltage applications.

There are two basic types of ACBs: fixed type and drawer type. The former is installed in a frame while the latter is install on special drawer base. The main components of an ACB include a mechanical switch, operating mechanism, current transformer used for protection, pole group insulating box, terminal box, arc extinguishing mechanisms and closing springs. There are different models of these devices ranging from 800A to 10KA.

Compared to vacuum circuit breakers, air circuit breakers are much easier to install because the protective relays are placed internally. They also offer a higher short circuit breaking capacity and are capable of preventing power failures. They are an ideal choice for motor control centers and power control center panels because they can help prevent overloading. This is because they can detect power loss and disconnect the current immediately. The arc chute in an air circuit breaker is formed from some type of product that’s refractory which helps to drive the arc into close proximity.