Electrical knife switch

Electrical knife switch is mainly made up of moving contact knife, fixed contact knife block, incoming and outgoing line block, these conductive parts are fixed on the porcelain bottom plate. Together with other protective devices: arc-extinguishing chamber, fuse, etc., all covered by an insulating cover.

So when the knife is closed, the operator does not touch the live part. The protective cover is to make sure the poles are separated from each other to prevent the short circuit caused by the arc between poles;

Prevent arc flying out of the cover, burn the operator; Prevent metal parts from falling on the knife to form a short circuit between poles.

The role of electrical knife switch in the circuit is mainly used for isolating power supply or manually connecting and disconnecting AC and DC circuits, but also for infrequent connecting and disconnecting load below rated current, such as small motors, electric furnaces, etc., act as a power switch, isolating switch, emergency switch and circuit protection.

There are many different types of knife switches, such as 2 phases knife switch, 3 phase and 4 phases electrical knife switch, regular rated current is 10A~3000A. For ordinary load, the rated current of the knife switch disconnect can be selected according to the rated current of the load;

For motor, consider its starting peak current up to 4~7 times the rated current, when selecting the rated current of the electric blade switch, it is better to choose about 3 times the rated current of the motor.

When installing the electrical knife switch, choose the dry, dust-free, not affected by vibration bright place, and equipped with a special distribution box or installed on the switchboard.

The power supply is connected to the fixed contact, and the switch is installed in the formal form according to the regulations, that is, the bottom plate of the knife should be perpendicular to the ground, the handle is upward, the fixed contact is located above the power supply, and the moving contact is located below the load.

In addition, the action of pulling and closing the knife should be convenient and flexible. Can not be reversed, that is, the connection state handle should be upward.

Otherwise, in the state of breaking, the knife switch may lose and fall causing misconnection. At the same time, it is not good for acr-extinguishing, because in the formal installation, hot air rises, the arc will be stretched and easy to extinguish.

When wiring, the incoming line and the outgoing line can not be connected inversely, otherwise an electric shock accident may occurs when replacing the fuse. Do not install horizontally either.