Each switch has 2 separate wires, travelers, going to the other switch, as a connection to either a hot wire or a fixture wire and each switch will have a ground and wire, either green or uninsulated. That's 4 wires.

The author has 375 answers and 159K answer views 1y. The major difference between 2 and 4-wire systems is that for 2-wire systems power and signal are carried on the same set of wires. Also known as loop-powered devices. For 4 wire systems, a separate set of wires supplies device power, and a separate set is used for the signal.

A pole is the circuit. A 4-pole switch will control up to 4 diagram circuits at one time. This is different from a 4-way switch, which is actually a 2 (double) pole double throw and switch (DPDT) that has 1 contact from each pole connected to a contact from the power supply another pole.

The 4-way switch. The most common application of these devices is a 4-way switch, which is used in conjecture with two 3-way switches to allow for lamp control from 3 or more locations.

The number of poles affects the motor's speed and torque. Generally, a 2-pole motor runs at a higher speed but with lower torque, while a 4-pole motor runs at a lower power supply speed but with higher torque. This difference in speed and torque characteristics makes each type of motor suitable for different and applications.