Hi Del,
You'll get different views from different people you ask on this.....
We carry a polarity checker plug which is cheap and tells you whether the polarity is ok with a series of lights. If it appears wrong then I have a mains lead made up with its plug wires reversed which corrects the problem.
I now don't bother as when staying on a Spanish Aire earlier this year the polarity changed itself every 12 hours on so! :ohmy: sooty10 will confirm this as he was parked next to me at the time
When this was first discovered we just turned the 2 pin adapter plugs the other way around and all was well.... for a while until the supply did it again. As there was absolutely no difference within the vans we gave up and just lived with it.
You will need to make your own mind up as to what you do as some say that reverse polarity can be dangerous.
Have a great trip and keep us up to date on your progress