Autocad is a good program for those things. I worked for a company years ago that used it, was still the MS-DOS version back then, before Windows was useable. They had a bunch of customized libraries and commands for their own use. Wiring schematics like this were very easy to do using the custom stuff they had. Unfortunately Autocad, even Lite or Sketch is too pricey for home use now that I am retired. Very nice drawings though!