Electrical

FYI, I used a 3-light tester to check my retractable power cord installation and found ALL 120VAC outlets reported HOT/NEUTRAL REVERSED when running on the generator. I connected to shore power and found all 120VAC outlets reported CORRECT! Contacted manufacturer to report this "Anomaly" Rig is going into the shop next week for a check-up!
The AC Line Tester is your Friend!!

Likely a bad ground on the cord. I had the same issue with a cord that had the ground pin broken off. Cut the cord end off and installed a new one, problem solved.

First thing is to unplug it immediately before you try and diagnose anything. A hot skin can be deadly. Even a slight tingle is a bad sign.

Mike Sokol of The-No-Shock-Zone has excellent info. on the RV hot skin condition and how to diagnose the causes. A good in-depth discussion with Mike Sokol discussion on another forum a few years here.

dup.

If a generator is 240 vac it has a viable neutral L0

If a generator is a 2-wire 120vac, it can not have a neutral. It would have to center tap the 120 vac sine wave to obtain a 60vac signal. It like all other 2-wire generators does not have an absurd center tap.

So a plug-in receptacle tester used here, is worthless to determine "polarity".

Plugged into shore power, there actually is a bonafide neutral regardless if the pole transformer is wound delta or wye.

But caution must be entertained if the service drop is three phase Delta. Two of the three phases would be viable but the third is a landmine.

MEXICOWANDERER wrote:
If a generator is 240 vac it has a viable neutral L0

If a generator is a 2-wire 120vac, it can not have a neutral. It would have to center tap the 120 vac sine wave to obtain a 60vac signal. It like all other 2-wire generators does not have an absurd center tap.

So a plug-in receptacle tester used here, is worthless to determine "polarity".

A single phase generator built into an RV has one of the sides of the 120V output bonded to the chassis ground, and so that side becomes the neutral in some sense. It is of course true that the entire system is floating (assuming one doesn't attach the chassis to a ground rod or something) and likewise that this is not a split-phase system with a well-defined neutral inherent to the output.

Showing a reversed polarity on generator means that the wrong connection from the generator is bonded to the chassis, or alternately that the output wires were transposed on their way to the transfer switch. It's a problem that should be corrected, and indeed can be fixed pretty easily.

Incidentally, there are some relatively rare situations where 60V split phase wiring is used. One such use is "technical power" systems for audio equipment in studios, scientific instruments in labs, and other areas where it's important to minimize induced noise; having the power supply balanced with respect to ground helps with that. Another place it's used is in construction site power in the UK, where legally the maximum voltage in the system cannot exceed 55V RMS with respect to ground in an effort to reduce shock and electrocution danger. Neither of these has any bearing on RV generator installations, of course.

Here we go again. Has this potentially serious problem been fixed yet? The OP needs to provide much more information about the trailer to obtain any meaningful help. How old is it? Manufacturer? Model? Size? Type of wall construction? Does it even have a generator installed? Any evidence of DIYer installed options? Is the entire metal skin electrified or just a portion of it? Is the frame electrified too? A picture is worth 1,000 words.

Don't assume that all the metal panels on the trailer have a common bonded ground, especially with older units. (corrosion, improper repairs, moisture damage, missing ground straps, etc.) Is the unit old enough that GFI circuits weren't required yet? No one knows but the OP and he/she ain't talkin'.

I've seen it several times where an owner installed an additional towel bar, toothbrush/soap holder, toilet/paper towel holder, etc. where the mounting screws penetrated the hot side of concealed romex wiring and electrified the accessory. Then when touched by hands with bare feet, YOU become the ground! Try flipping the 120 volt breakers one at a time. Does the condition go away? Troubleshooting 101. Get all the information available, then check the most simple things first.

Chum lee