Joel,
I believe you are correct. I was pretty sure there was a "surge" protector in the MH, but wasn't sure if it monitored voltage,etc. So after banging my head a couple of times today, I found the unit and iit is in back of the bay compartment - a Surge Guard by TRC.
Reading the literature more closely, it does protect against high (>132v) and low (<102V); in either case it disconnects the service. Also monitors faulty wiring, reverse polarity and open neutral.
Lesson to me: READ THE MANUAL MORE THOROUGHLY - DON"T JUST SKIM THROUGH IT!