Bob,
I had given some thought to doing this at one point. We had a thread where we discussed this. Should be able to find by doing a search. After our discussion here, I decided what I really needed was an autoformer to keep the AC power at an appropriate level. I installed the autoformer and we have been able to use the airconditoner and Washer/Dryer simultaneously without any problems. Our rule is to use only two "big" power users at the same time, i.e. W/D, airconditioner, hair dryer, electric water heater, etc. Lighting and television are OK using any of the other two "big" power users at the same time.
Previously, we were having problems with breakers tripping when we had a large power load. I checked the voltage in the coach when this would happen and it was not unusual to see 100-108 volts. Not only is it agravating for the breakers to trip it is really hard on electric motors in your airconditioner, washer, etc. The autoformer keeps the voltage at an acceptable level and in my case I decided I didn't need to upgrade to a 50 Amp service. Here's a link to my website if the autoformer sounds like something you'd be intrested in.
http://www.geocities.com/fulltimedre...vprojects.html