I recently referred to the need we have to learn something about other trades- how their stuff works, what the components look like, etc. Paul, your pics bring this lesson home.
Gone are the days when a "sparky" could content himself simply pulling wires and hooking up devices. More and more, homes are getting rather involved control circuits in them.
Apart from fancy heat pumps and air handlers, more homes are getting indoor spas, involved lighting schemes, automated things like window shades, and generating equipment.
