Lennox 21G77 Transformer 208/240V 100VA

The Lennox 21G77 Transformer 208/240V 100VA is an electrical conversion component used to provide reduced voltage power for equipment control circuits. It is installed inside the electrical compartment, where it connects to the incoming power supply and low-voltage control wiring. The internal coil arrangement converts higher voltage input into a lower output level required by connected relays, sensors, and control devices. Voltage conversion within HVAC systems allows electrical controls to operate correctly, coordinate equipment responses, and maintain proper communication between connected components during heating and cooling operation.