Control and protection switch electric appliance

Abstract

The invention relates to a control and protecting switch apparatus, which belongs to the technical field of automatic control of electric motors. The control and protecting switch apparatus is mainly characterized in that a permanent magnet driving mechanism and a control circuit adapted to the permanent magnet driving mechanism are arranged on a base, when switching-off in work, magnetic force generated by pulse and electrodynamic force generated on a moving iron core enable the moving iron core to move to pull in a fixing iron core to form a closed magnetic circuit, and simultaneously a main contactor is enabled to be switch-on, the pull-in of the switch is kept by the magnetic force of a permanent magnet, when switching off, reverse magnetic force and reverse electrodynamic force generated on the moving iron core counteract the pull-in force of the permanent magnet, and the main contactor is fast switched-off under the action of a switch off tensional spring. For coils don't need to be electrified to work for a long time, the invention is high-efficient and energy-saving, has unheated coils, is fast in switching-off speed and not connected in contacts without critical bounce, and can efficiently prolong the service life of the contacts. The invention has extremely strong practicability, is an updated product of the existing control and protecting switch apparatus which utilizes an electromagnetic driving mechanism, and can be widely applied to power supplying circuits of electric motors.

Description

technical field

[0001] The invention relates to a control and protection switching device, which belongs to the technical field of motor automatic control. Background technique

[0002] In the traditional motor power supply circuit, the control and protection of the motor are generally realized by circuit breaker (QF) + contactor (KM) + thermal relay (KH). Under normal circumstances, the contactor (KM) realizes the on-off of the control circuit, the thermal relay (KH) realizes the overload protection, and the circuit breaker (QF) realizes the short-circuit protection. In actual use, if the above three discrete components are improperly selected, coupled with the poor working environment of the motor, and the protection function is not perfect, a large number of motors have overload short circuit, phase loss, grounding and other faults every year, causing serious equipment damage. Accidents and huge economic losses cannot guarantee the long-term stable and normal operation o...

Images