For some reason, heating system wiring seems to mystify some people ... (See Figure 4, page 20.) This wiring diagram shows 120 V coming from L1 of a circuit breaker, through a switch, powering a ...

"This HVAC training video program ... A/C and heat pump wiring diagrams. Other programs that cover three-phase equipment, magnetic starters, part winding start systems, and high and low voltage wiring ...