Push-Button Starter

a manual control device for on-and-off switching of electric installations, electric motors, electric heating equipment, and other electrical devices.

A pushbutton starter has two pushbuttons, one of which is connected to a contact-closing lock mechanism and the other to a contact-disengaging mechanism. The disengaging mechanism may also be connected to a thermal relay, in order to protect the circuit from overload. The contact system is usually constructed in a bridge design, providing a twofold interruption of electric circuits upon disengagement of contacts. The contacts are separated by interphase plates or enclosed in arc-extinguished chambers. The body and the housing of a pushbutton starter are made of plastic or metal. Pushbutton starters are made in one-phase or three-phase designs and in open, closed, and dust-and-vapor-proof models. Under normal operating conditions pushbutton starters are capable of up to tens of thousands of operations. Maximum power rating is 10 kilowatts at voltages of 220 to 380 volts.