What mechanism does a contactor use to operate?

A contactor operates through electromagnetic coils. When an electrical current flows through these coils, they create a magnetic field that pulls in a moveable armature. This action closes the contacts within the contactor, allowing electrical current to flow through the circuit to power connected devices such as motors or compressors.

The design of a contactor relies on this electromagnetic principle, as it allows for a sizable amount of electrical power to be controlled by a relatively small control signal. This is essential in HVAC systems where efficient control of high-power components is necessary without requiring extensive manual intervention.

Other mechanisms like mechanical levers, pneumatic pressure, and hydraulic pressure are typically used in different applications or devices but do not apply to the functioning of contactors in HVAC systems.