Need help adding a transfer switch

88flaminchevy wrote:
Why is there a jumper installed between Neutral and AUX? Please someone correct me if I'm doing something incorrect.

Because as the directions say, you can use connect both L1 and L2 to the same 120V leg (giving up 240V) and if you do so, the neutral needs 2x the capability to handle both L1 and L2 in phase. They do this by doubling up aux and neutral. Seems a little hokey to me in that if aux or neutral were to fail in the transfer switch you'd end up overloading the other one without knowing it.

I'm not sure if your generator is dual 120V or 240V. If it's 240V, I'd leave it like you have it with L1 and L2 to the 240V "hot" legs from the generator and don't worry about the aux jumper or connection. You shouldn't have anything in the trailer connected to the aux terminal if you leave L1/L2 as 240V. Just because the generator makes 240V, it doesn't mean you need to use 240V. You can still use both "sides" at 120V each. In your trailer, connect your 120V devices across L1/neutral or L2/neutral in a somewhat balanced fashion.

If it's dual 120V (i.e. in phase), connect one white to neutral and the other to aux, but leave the shorting jumper in there.

If you only have a 120V shore power cord, you can feed both L1 and L2 of the transfer switch with the one hot feed. Be sure you have proper breakers that won't exceed the capability of the single neutral wire or shore cord.