Datasheet

US Catalog | Miniature Circuit Breakers 43
Lower terminal
Space for
identification marker
Tripping lever
Moving
contact
DIN rail holder
Operating
mechanism
Upper terminal
Electromagnetic protection
Thermal
protection
(bimetal)
Arc chamber
Fixed
contact
Operator
Thermal Example
10 A
Breaker
Light
15 A
The light draws more than 10 amps for
an extended period of time creating a
thermal overload.
Magnetic Example
10 A
Breaker
Light
10 A
The wire connected between the light and
breaker is cut and shorted to ground
creating a short circuit.
Application guide—Miniature circuit breaker
Introduction
The circuit breaker plays an important role in providing over-
current protection and a disconnect means in electrical networks.
Recent advancements in circuit breaker technology has increased
breaker performance and protection.
Overload
An overload is a slow and small overcurrent situation that causes
the ampacity and temperature of the circuit to gradually increase
over time. This type of event is characterized by a slight increase
in the load (ampacity) on the circuit and is interrupted by the
thermal trip unit of the breaker.
Breaker definition
A breaker is a device designed to isolate a circuit during an
overcurrent event without the use of a fusible element. A
breaker is a resettable protective device that protects against
two types of overcurrent situations: overload and short circuit.
ABB current limiting breaker
Short circuit
A short circuit is a rapid and intense overcurrent situation that
causes the ampacity of the circuit to increase. This type of event is
characterized by a dramatic increase in the load (ampacity) on the
circuit and is interrupted by the magnetic trip unit of the breaker.