Automatic reset circuit breakers are cycling or continuously self-resetting devices that open by combinations of overcurrent and elevated temperatures.

Automatic reset circuit breaker are the most basic design of the thermal circuit breaker family. As cycling or continuously resetting devices, their usage is best applied protecting loads controlled by momentary switches or other self-limiting means.

The plus aspects of type I circuit breakers are:

1, Simplicity of design.

2, Lower cost as a component.

3, Nothing to reset after a trip event.

9301	9301A	9301AX	9301X	9302	9303	9306	9306A	9306L

Modified reset circuit breakers are devices that are opened by overcurrent and remain open as long as the power is on to the affected circuit or until the load is removed.

A number of cycles may occur before achieving a steady-state open circuit condition.

The plus aspects of type II circuit breakers are:

1, Simpler design alternative to type III breakers when type I usage is undesirable

2, Can be reset from any point in the same circuit where power switching is possible

3, Less likely to drain storage batteries before fault is detected and corrected.

4, Encourage timely maintenance since components affected are not functional even intermittently as with type I.

9304	9304L	9305	9305R	9305X	9307

Manual reset circuit breaker are non-cycling devices that open by overcurrent and elevated temperatures, but remain open until manually reset into a conducting state.

Type III circuit breakers are used where no cycling after a fault is desired or deemed safe and where an immediate investigation of fault causes is the most appropriate course of action.

The plus aspects of type III circuit breakers are :

1, Highly unlikely to permit damage to wiring or interfaces from long-term fault exposure.

2, Can provide circuit interruption for maintenance or investigation (if with switchable feature).

3, Provide operators with a sense of control and awareness over electrical systems.

9301N