30A Upgrade to 30A + 20A

[Wayne Olson]

Many of us have wanted to run both the front and rear AC units at the same time when plugged into the campground electric power. Ever wondered why we can run both AC units when we are running the GenSet but not when plugged into 30A service. That is because the generator produces more power than the standard 30A electric service. Upgrading your AS 30A service to 50A, like most new class A motorhomes, is possible but requires significant cost and modification.

We solved this problem with an inexpensive upgrade (< $100) from Power Solutions, 704-398-0996 called "Dual Power Adaptor" (see installation drawing below). Basically this is a junction box mounted in the generator compartment that allows an additional standard 20A cord to be plugged into electrical service along with the 30A cord. Once plugged in, the rear AC is no longer controlled by the rotary selector switch above the stove and is powered by the new 20A service. Everything works normally when the 20A service is not plugged in.

A scan of the AS Generator Switch-Over Relay diagram (with added notes) taken from the AS MH Manual and a hand drawing of how I wired our Dual Power are both attached. I have wired both our current 345 and the one owned by Robfike as described. Both worked great. We have found that most every place we go that has 30A service also has an extra 20A standard plug available.

Hope this helps you stay cool on those very hot summer days.
Wayne