The Hartland Controls HCT-04E0AA03 Transformer features a 480V primary and 24V secondary output with a 40VA rating, delivering reliable low-voltage power for HVAC control circuits. Designed for furnaces, air handlers, and commercial heating and cooling equipment, it works by stepping down high input voltage to a stable control voltage for thermostats, relays, and safety devices. https://www.partshnc.com/hct-04e0aa03-hartland-controls-480v-pri-24v-sec40va-transfor