A popular electrical diagram used by manufacturers to illustrate the installation connections for equipment.
“The third and last type of diagram is the installation diagram. This is a tool that is used primarily by the installing contractor. It normally shows only what the terminal board connections are, and very rarely will it include any internal wiring of the unit.”
EXCERPT FROM ELECTRICITY FOR HVACR TECHNICIANS available from the online store at RSES (Refrigeration Service Engineers Society) The HVACR Training Authority.