An adjustable thermal trip mechanism for a circuit breaker is provided which can improve the reliability of over-current tripping by minimizing an influence upon thermal tripping even if an assembly error such as skewing or twisting occurs during assembly of bimetallic strips. The adjustable thermal trip mechanism for the circuit breaker comprises: a crossbar that is rotatable and has at least one power receiving portion for receiving rotary power; a bimetallic strip that can bend towards the power receiving portion when an over current occurs on the circuit; and an adjustment screw installed to face the power receiving portion, wherein the power receiving portion comprises a plurality of planar portions which are at different distances from the adjustment screw.

An electric switch includes a thermal tripping unit which, when a thermal budget acting on it is exceeded, trips and switches off the electric switch. In an embodiment, the tripping unit includes an adjustment module which, as a function of an accessory connected to the electric switch, uses an actuating element to set a tripping element of the thermal tripping unit such that the heat effect of the accessory is compensated for in the event of tripping.

An electric switch includes a thermal tripping unit which, when a thermal budget acting on it is exceeded, trips and switches off the electric switch. In an embodiment, the tripping unit includes an adjustment module which, as a function of an accessory connected to the electric switch, uses an actuating element to set a tripping element of the thermal tripping unit such that the heat effect of the accessory is compensated for in the event of tripping.

An electrical protection unit A including a main conductor and, for each main conductor, a current limiter device connected in series with the main conductor to limit the current when a current or temperature threshold is exceeded, the limiter device including an element made of a material having a positive temperature coefficient, called PTC, and being capable of controlling a device for tripping the mechanism M for opening the contacts of the protection unit D, to cause the opening of the contacts of the unit when the threshold is exceeded leading to a change of state of the element between a low resistance state and a high resistance state. The PTC element includes the trip device, in such a way that this element itself provides the functions of fault current limitation and of tripping the mechanism for opening the contacts.

A circuit breaker having a frame comprises a bimetal plate having a longitudinal length wherein the bimetal plate is cut along the longitudinal length into a narrow section and a wider section both being parallel to each other such that the bimetal plate is configured to control when and how a trip mechanism of a trip unit activates. The circuit breaker comprises a heating element coupled to the bimetal plate to heat the narrow section and the wider section when a current goes through the heating element. The narrow section and the wider section of the bimetal plate to deflect differently when a same amount of heat is applied in a same amount of time to control when and how the trip mechanism activates such that to allow to have two different current ratings in the frame in that the bimetal plate allows to increment a current protection level from a lower current rating to a higher current rating.

A circuit breaker having a frame comprises a bimetal plate having a longitudinal length wherein the bimetal plate is cut along the longitudinal length into a narrow section and a wider section both being parallel to each other such that the bimetal plate is configured to control when and how a trip mechanism of a trip unit activates. The circuit breaker comprises a heating element coupled to the bimetal plate to heat the narrow section and the wider section when a current goes through the heating element. The narrow section and the wider section of the bimetal plate to deflect differently when a same amount of heat is applied in a same amount of time to control when and how the trip mechanism activates such that to allow to have two different current ratings in the frame in that the bimetal plate allows to increment a current protection level from a lower current rating to a higher current rating.

An electrical protection unit A including a main conductor and, for each main conductor, a current limiter device connected in series with the main conductor to limit the current when a current or temperature threshold is exceeded, the limiter device including an element made of a material having a positive temperature coefficient, called PTC, and being capable of controlling a device for tripping the mechanism M for opening the contacts of the protection unit D, to cause the opening of the contacts of the unit when the threshold is exceeded leading to a change of state of the element between a low resistance state and a high resistance state. The PTC element includes the trip device, in such a way that this element itself provides the functions of fault current limitation and of tripping the mechanism for opening the contacts.

Embodiments provide systems, apparatus, and methods for circuit breaker tripping. Embodiments include providing a circuit breaker with a thermoelectric tripping mechanism, the thermoelectric tripping mechanism including a thermoelectric plate disposed between a current path and a bimetal lever of the circuit breaker; applying a DC current to the thermoelectric plate to heat the bimetal lever; and deflecting the bimetal lever to press upon a trip bar in response to a current overload occurring on the current path. Numerous additional aspects are disclosed.

Embodiments provide systems, apparatus, and methods for circuit breaker tripping. Embodiments include providing a circuit breaker with a thermoelectric tripping mechanism, the thermoelectric tripping mechanism including a thermoelectric plate disposed between a current path and a bimetal lever of the circuit breaker; applying a DC current to the thermoelectric plate to heat the bimetal lever; and deflecting the bimetal lever to press upon a trip bar in response to a current overload occurring on the current path. Numerous additional aspects are disclosed.

An adjustable thermal trip mechanism for a circuit breaker is provided which can improve the reliability of over-current tripping by minimizing an influence upon thermal tripping even if an assembly error such as skewing or twisting occurs during assembly of bimetallic strips. The adjustable thermal trip mechanism for the circuit breaker comprises: a crossbar that is rotatable and has at least one power receiving portion for receiving rotary power; a bimetallic strip that can bend towards the power receiving portion when an over current occurs on the circuit; and an adjustment screw installed to face the power receiving portion, wherein the power receiving portion comprises a plurality of planar portions which are at different distances from the adjustment screw.