Ac Thermostat Control Wiring

The green wire underneath your thermostat connects to the fan of your furnace or air handler.

Ac thermostat control wiring.

The common wire sometimes referred to as the c wire is what s responsible for delivering constant power to your thermostat. They control your air conditioning system. The yellow wires connect to the y terminals on your thermostat. For programmable thermostats and smart thermostats c wires are essential for setting a schedule or having your heat or air conditioner turn on at a desired temperature.

Furthermore it will be one of the few control wires thermostat wires that will terminate at the condenser in a split system air conditioner and heating system. Typically the yellow wire will be run to the air handler where at the air handler this wire is usually connected to another wire typically by a wire nut. The yellow wires terminate at your compressor contactor via an air handler. Air conditioner thermostat wiring details and color code r terminal is connected to the red wire or r wire this is 24 volt power for the thermostat and controlled devices.

If your home s system of this vintage has provisions for air conditioning cooling then the thermostat wiring will have at least three wires some will require a separate r terminal for heating and cooling and will be labeled rh and rc now needing a minimum of 4 wires r w and a y terminal.