What is the role and functions of the circuit breaker in a generator?

Not only of an alternator and an engine lives a Grupel generator. Therefore, we look carefully and in detail at all the elements that make up and contribute to the proper functioning of our products, which include sensors, switchgear, resistors and, among others, circuit breakers.

We try to have more and more of these components in our own brand, because we believe that, investing on the quality of each piece, we can differentiate our final product, making it increasingly competent and worthy of trust.

Grupel circuit breakers are therefore produced with rigor and serve their purpose exactly, preventing the electrical installation from suffering overloads and short circuits, which would compromise windings and installation, and cause permanent damage to the generator. In addition, as they provide the sectioning of circuits, they also serve to switch circuits and loads on and off.

Grupel circuit breakers are thermomagnetic and therefore protect the installation in two ways:

  • The thermal protection moors the circuit breaker when the output current of the generator is higher than the dimensioned and predefined current, during a certain period;
  • The magnetic protection serves to protect the equipment against current surges that exceed the rated power and, therefore, to avoid short circuits.


As the amperage of the installations increases, equipment with greater cutting power and more protection is required. For this reason, Grupel has:

  • miniature circuit breaker (MCB), up to 125A;
  • molded case circuit breaker (MCCB), from 160 to 1600A;
  • and air circuit breaker (ACB), from 1600 to 2000A.


MCB circuit breaker

The MCB circuit breaker (3 or 4 pole) has the following accessories:

  • auxiliary contact, which allows sending a signal about the status of the circuit breaker (whether it is open or closed) remotely;
  • auxiliary contact with alarm, which allows sending an alarm about the status of the circuit breaker;
  • shunt trip relay or shunt release, which is controlled via an external source and allows to open / close the circuit breaker remotely.


MCCB circuit breaker

This MCCB circuit breaker (3 or 4 pole) has the following accessories:

  • auxiliary contact;
  • alarm contact, used to give alarm in case of breaker failure;
  • shunt release, for remote control;
  • motorization, which serves to control the circuit breaker automatically and remotely, for example, when there are several generators in synchronism. In this case, a circuit breaker equipped with motorization allows the controller to determine its opening and closing.


ACB circuit breaker

This circuit breaker (3 or 4 poles) does not need accessories, since it already has features, such as auxiliary contact and remote control, and more protections.

Grupos electrogéneos Grupel+Grupel - Energia de Portugal para o Mundo