This is the electrical scope that mechanical equipment depends on: the circuit, the disconnect, the connection and the control wiring. Equipment that trips, fails to start or loses its controls is often an electrical problem rather than a mechanical one.
We wire and connect furnaces, heat pumps, air conditioners, mini-splits, pumps and motors, and coordinate with whoever is supplying or servicing the equipment. Mechanical design, ductwork and refrigerant work are outside this scope.