I have an evaporative cooler with 120VAC control that I want to switch on and off using a relay that is activated when the cool call comes from my thermostat. I plan on just using 1 relay to activate the whole cooler control (rather than multiple relays to control the different aspects of the cooler), so this is a simple on/off when cooling call comes from the thermostat.
All of the wiring for the thermostat goes to the air handler and then heat, fan, etc. kick on from there. I have a C wire running to the thermostat. My thought was that I just put the relay in line with the Y wire (run Y from thermostat to relay, then out from relay to the air handler). This puts 24VAC across the relay (which is what the relay is rated for), but does not throw the switch.
Best Answer
You'll want to connect the
YandCwires to the coil of the relay, so you end up with something like this.When the temperature switch in the thermostat closes (calling for cool), 24 volts will be applied to the relay coil.This should pull the contact in the relay to the normally open (NO) position, allowing electricity to flow to the evaporative cooler (or whatever 120V device needs to be powered).