What is an Electrical Contactor?

Question

What exactly is an electrical contactor?
Can a three pole contactor be used in a single phase circuit?

Answer 1

A contactor is an electrical component for switching on and off the power by creating an open circuit.
There is a coil of fine copper wire surrounding a ferrous material (iron) plunger which. When a current is applied to the coil the resulting electromagnetic force pushes the plunger in or out, causing the contactors to open or close.
Depending on what voltage the coil of the contactor is you can use a three phase contactor on a single phase circuit.
Check that the voltage rating for the contacts and the coil as they may be different.

Answer 2

A contactor is an electrically controlled switch used for switching an electrical power circuit, similar to a relay except with higher current ratings.[1] A contactor is controlled by a circuit which has a much lower power level than the switched circuit.

Contactors come in many forms with varying capacities and features. Unlike a circuit breaker, a contactor is not intended to interrupt a short circuit current. Contactors range from those having a breaking current of several amperes to thousands of amperes and 24 V DC to many kilovolts. The physical size of contactors ranges from a device small enough to pick up with one hand, to large devices approximately a meter (yard) on a side.

Answer 3

In other branches of electrical engineering, it is called a "relay", but in serious power engineering the term contactor is used. Same thing, just bigger, heavier, more current capability, friend of electricians.

Answer 4

ZORCH got part of your question right, for part 2, yes it can. Just wire all of the contacts together for the input, and the same for the load side.