You never mention the generator you're using. Portable generators such as the paired (paralleled) Yamaha EF2000is units I use (also true for the Honda EU2000i generators) have a floating neutral that's not bonded to ground. If I plug them into the 50 amp twist-lock generator plug (using a 50 twist-lock to 30 adapter) on the front of our 5th wheel, the Progressive Industries power protection system will block the generator output with an E9 error code and not engage the transfer switch UNLESS I have a neutral-to-ground bonding plug plugged into a 15 amp outlet on one of the generators. If your generator requires it, do you have the bonding plug installed?
Rusty
