Control Wiring Exercises
Two wire control is usually used for a simple ON/OFF device such as a toggle switch, float switch, thermostat, or other device that would switch off of a high/low limit.
It is one of the most basic and common circuits which is even used for household 2 way light circuits yet it is often misunderstood. All circuits must make a complete loop from the power supply, through the switch, then through the load, then back to the power supply.
In this video we show you how to wire a 2 wire control circuit to a relay and a light.
See image below for an example of 2 wire control being used to pull in a contactor to start a 3 phase motor. When the 24VDC relay energizes, it pulls in the R1 contactor that feeds three phase power to the motor.