Switchgear, for over-current protection, has polymer positive temperature coefficient element which gets expanded due to change to high impedance condition causing mechanical unlatching of latch, by which main contact is opened

摘要

Switchgear has a pair of main contacts (3), whose movable switching contact (6) can be controlled over the switch latch (5). The expansion of the polymer positive temperature coefficient (PTC) element (4) occurring due to the change to the high impedance condition causes the mechanical unlatching of the switch latch, by which the pair of main contacts is opened.