Circuit Breaker Types


Before discussing different circuit breaker types, it is important to understand the proper function of a circuit breaker.  Circuit breakers are rated for a maximum (or fixed) electrical load capacity and automatically break the electrical circuit when that load capacity is exceeded.  This is known as tripping the breaker.  Cutler Hammer breakers detect when a fault condition exists and automatically interrupts the continuity of the electrical circuit immediately stopping the flow of electrical current.

circuit breaker types

An overload of a Cutler Hammer breaker will occur when wires are forced to conduct and carry an electrical charge greater than the capacity of the Cutler Hammer breaker.  Without various circuit breaker types installed, wires can generate excessive heat that causes the wire insulation to break down, eventually starting an electrical fire.  Exposed wire can also cause a short circuit, or a condition where exposed wires come in contact with each other and causes unwanted current flow.  This condition can result in circuit damage, excessive heating, explosions and fire.  Therefore, it is extremely important to select the correct circuit breaker types for your residential or commercial project from the Cutler Hammer Catalog.

Mechanism of a circuit breaker

Cutler Hammer circuit breaker types

When installing a circuit breaker, it is important to match your Cutler Hammer breakers with Cutler Hammer panels.  Generally speaking, depending on which circuit breaker types are involved, the circuit breaker will have two conductive contact plates, one stationary and one that is moving.  When the Cutler Hammer breaker is switched to the ‘on’ position, a conductive contact plate in the switch moves into direct contact with the stationary conductive contact plate and the circuit is complete.  This allows electricity to flow.  When the breaker is overloaded or short-circuited, the breaker is tripped and the switch plate snaps back quickly from the stationary plate, breaking the circuit.

Cutler Hammer circuit breaker types

Circuit breaker types

In order to classify different circuit breaker types, Cutler Hammer breakers are broken down into different categories.

LOW VOLTAGE CIRCUIT BREAKERS:  These Cutler Hammer breakers are designed for residential, commercial and industrial applications.  These circuit breaker types carry direct current (DC) and are typically installed in Cutler Hammer panels that match up with the breakers.  For example, in a residential application, commonly a 200 amp Cutler Hammer panel will be used.  Different circuit breaker types that are low voltage include molded case circuit breakers (MCCB) and miniature circuit breakers (MCB).

MEDIUM VOLTAGE CIRCUIT BREAKERS:  These Cutler Hammer breakers are typically housed in switchgear line ups that are enclosed in metal for an application that is indoors, or outdoors at a substation as an stand alone component.  These circuit breaker types are usually bolted to bus bars and use protection relays and discrete current sensors.  Some examples of medium voltage circuit breakers are air circuit breakers and vacuum circuit breakers.

HIGH VOLTAGE CIRCUIT BREAKERS:  These Cutler Hammer breakers serve in protecting and controlling networks involved in high power transmission.  These circuit breaker types use protective relays in conjunction with a current transformer and are solenoid based.

high voltage circuit breaker types

THERMAL CIRCUIT BREAKERS:  These Cutler Hammer breakers are designed to trip or break the electrical circuit at a certain temperature.  The breaker employs a metallic strip that consists of two metals that are welded together.  When the circuit breaker heats up, the bimetallic strip bends at an angle, throwing the breaker switch and disrupting the electrical current.

MAGNETIC CIRCUIT BREAKERS:  These Cutler Hammer breakers are fascinating and use a multi-dimensional electromagnetic coil.  As the electrical current increase, so does the electromagnetic force.  When the current becomes too great, the electromagnetic force pulls the breaker switch and the electrical circuit is broken.

Additional circuit breaker types include earth leakage circuit breakers, common trip breakers and rated circuit breakers.  When considering which circuit breaker types to use in your project, be sure to see the advise of a Cutler Hammer distributor.  All of the above mentioned circuit breaker types can be ordered from the Cutler Hammer catalog.