The time of problem will be when you are on shore power and the refig is running on 120 volts. Check the current rating on the refig and the microwave. If the combination is less that 16 amps you should be OK. Just make sure that the receptacle behind the refig is on a dedicated circuit or other things may be effecting the total current on that circuit.
The univbolt is not a consideration when dealing with 120 volt circuits.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles