Here is the subpanel:
It is currently on a 50 amp feeder breaker, therefore, we have the breaker on the GFI off. The 6/3 wire into the subpanel is wired exactly as the diagram on the door panel. Red/Red, Black/Black, White/White, and Ground/Ground.
AC behavior while connected to the active subpanel - Initially, all light switches, appliances, air conditioner, etc work as expected. A short time later, turning on a light switch for a DC light, slows or kills an active fan. Eventually, the air conditioner kicks off but its fan will still run a bit longer. The refridgerator will eventually shut down though the TVs will stay on.
R-B 50AMP main panel= 228vac