Types of circuit breakers, what are they?

How many types of circuit breakers do you know? If you still don’t know there are several types of circuit breakers, in this article Mundo da Elétrica makes a TOP5 of the main types of low voltage circuit breakers. Come on!

TOP5 types of circuit breakers

The circuit breakers are protective devices are also known by the older people as a general switch. We can say that the most common and simple circuit breakers protect the installations , cables and equipment against overload, which is the gradual increase of the electric current. This increase in electrical current happens as more electrical devices are inserted into the circuit. Circuit breakers also protect against short-circuit, which is an instantaneous increase in electrical current in the circuit. This is due to equipment or installation failures.

Overload and short circuit protection.

There are other types of circuit breakers that offer other types of protection. These circuit breakers in our TOP5 are low voltage circuit breakers, that is, they are used in installations with voltage below 1000V, such as a home for example.

DIN mini circuit breaker and NEMA circuit breaker.

The first type of circuit breaker is the DIN mini circuit breaker and the NEMA circuit breaker, both of which are the most commonly used in residential electrical installations. The DIN mini circuit breaker and NEMA circuit breaker provide thermomagnetic protection for overload and short circuit.

The DIN mini circuit breaker and NEMA circuit breaker offer thermomagnetic protection.

What differentiates DIN from NEMA is the standard they meet, the DIN circuit breaker meets the DIN standard (Deutsches Institut für Normung), which represents regulations for trade, industry, science and public institutions related to the development of German products.

And the NEMA circuit breaker meets the NEMA (National Electrical Manufacturers Association) standard, the standardization body located in Washington, USA, responsible for publishing technicians, but does not test or certify products. But regardless of the standard they meet, DIN and NEMA are effective in protecting electrical installations.

Molded box

The second is the molded case circuit breaker, this circuit breaker is a more robust circuit breaker that at first has the same protections as mini circuit breakers, but molded case circuit breakers withstand much stronger short circuits.

Some models of molded case circuit breakers have adjustments to modify some configurations, such as the nominal current, the opening time, among others, in addition to the addition of accessories, such as trip coils.

Molded case circuit breakers withstand much stronger short circuits.

The molded case circuit breaker somewhat resembles a NEMA circuit breaker, however the molded case circuit breakers meet an ABNT standard.

The molded case circuit breaker looks like a NEMA circuit breaker.


The third type of circuit breaker is a DDR, residual current circuit breaker, circuit breaker that many electricians do not know or have never seen. In addition to overload and short circuit protection, DDR also has protection against electrical current leakage, as it is a circuit breaker that has an integrated DR.

DDR, residual-current circuit breaker.

Current leakage protection is important protection because it can help protect people from electric shock, also being triggered by current leakage, from a minimum leakage current value.

Breaker engine

The fourth type of circuit breaker is the motor circuit breaker  and as the name implies, this is the circuit breaker used to protect electric motors. The motor circuit breaker offers protection against overcurrent and short circuit but at levels suitable for an electric motor that has different characteristics from other circuits and electrical loads.

The motor circuit breaker has a specific trip curve and is very different from mini-DIN circuit breakers . Starting motors often require 8 to 15 times the rated operating current, that is, a mini circuit breaker would trip every time the engine starts.

Another advantage of the motor circuit breaker is the regulation of the rated electric current of the motor operation. Every motor circuit breaker has a selector disk where it is possible to adjust the current to better protect the electric motor.

Motor circuit breaker has a specific trip curve.

Circuit breaker open

The fifth is the open circuit breaker . Of low voltage circuit breakers, the open circuit breaker offers the greatest number of protections. In addition to overcurrent and short circuit protection, the open circuit breaker can offer protection for current leakage, reverse power, phase failure, over-voltage, under-voltage and many other protections.

Unlike all the other circuit breakers we talked about, the open circuit breaker can be serviced and parts replaced. The open-circuit breakers are used for high electrical currents reaching up to 6,300A. Open circuit breakers are for more complex installations, that is, to install and configure this type of circuit breaker, specialized and trained electricians are required.

The open-circuit breaker offers the greatest number of protections.