The molded case circuit breakers are designed to make and break working currents as well as small inductive and capacitive currents. In the so-called In distribution circuits (the circuit supplying distribution boards), circuit breakers are usually the most important switching and protection devices.

MCCBs are otherwise known as ACBs. They are characterized by a compact and compact design (hence their name), enclosed in an insulating housing with small dimensions. These devices have very good switching properties and are characterized by effective extinguishing of the electric arc when interrupting a shorted circuit (efficient extinguishing of the electric arc in the relay is the basis for long trouble-free operation and safety of the installation). In the open state, most of the design solutions in circuit breakers  provides a visible insulation gap.

The principle of operation of MCCBs

The general principle of operation of the power circuit breaker says that in the switched circuit, the current causes the formation of an electric arc, while the activation of the circuit breaker is related to extinguishing the arc current, and the extinguishing mechanisms are different.

MCCBs are most often used in low-voltage industrial installations and in public utility buildings, where operating currents reach up to 2500 A and higher. They are used:

  • in AC and DC switchgears as main or emergency switches in incoming and outgoing bays,
  • for protection and control of electric motors, generators, energy capacitors,
  • for protecting wires and busbars in switchgears.

Advantages of MCCBs

Small dimensions combined with rich additional equipment make this type of circuit breakers important and often used protection elements in electrical installations. Their significant advantages include:

  • quick reset capability,
  • extensive diagnostic capabilities,
  • reclosing capability after circuit failure has been removed.

MCCBs offered by El12 can be selected due to:

  • manufacturer,
  • rated voltage,
  • number of polesó,
  • rated current.

When selecting the appropriate power circuit breaker, it is necessary to take into account the voltage and current rating of the devices connected to the network. It is very important to sum up all the values for the entire circuit.