Steve_Cox wrote:Hypothetically writing. On your AC power the neutral and the ground are bonded together and the ground is bolted to the frame. You go to "Poppy's by the Tree" campground and it turns out Poppy is an amateur electrician. You get the campsite with reverse polarity (all Poppy's campsites have reverse polarity). You set up and plug in your power cord. <B>You go to take your bicycle off the tongue mounted bike rack and suddenly you find that you can't let go of the handlebars because you're getting about 112 of the 117 volts available right into your continuously constricting muscles in your hands. Don't you wish for a split second you hadn't tied the ground to the frame</B> as you feebly jump into the air to get your wet bare feet off the damp ground and break the circuit?
Steve in St Augustine
Steve, you put into words my doubts of frame grounding the 120VAC coming into the trailer. I didn't think about the possibility of reverse polarity making the frame carry a positive charge. Since my trailer cabin is made of wood, and I plan to carefully avoid putting any screws or brads where I have run a wire with 120VAC current, I could only see making a problem with the frame being grounded that woudn't exist if it were not grounded. I think I'd rather carry a metal rod in the trailer to pound into the ground to connect my ground wire to. And if the ground were wet around it, you might still get a shock if the polarity were reversed.
As for the 12V systems. I removed my tail/stop lights from my boat trailer, because all that I've tried over the years eventually get water inside and corroded. I made a light bar that I strap onto the rear of the boat deck to travel and remove and put in the back of the truck when the boat goes into the water. There is no ground connection between the lights and the boat or trailer frame. The ground wire and light grounds all connect to the aluminum bar, and one wire runs to the connector with the positive wires and connects to the tow vehicle's ground via the connector. There is no reason for having frame grounding on the trailer for tail/stop lights either since I'll run the ground wire to the connector. BTW, I have experienced the weird way lights react with a bad ground to the tow vehicle. Unless you have done it, it's hard to believe what happens to your lights. It drove me crazy until I checked and fixed the ground.
Same as above with the internal lights and other 12V systems. With a ground wire run back to the battery/converter for each light/fan/outlet, I see no need for frame grounding except as a "backup" ground, and to have that you'd have to individually frame ground each light, fan, outlet, etc. in order to use the frame as a "backup" ground. OK, I can frame ground this system if everyone thinks it's necessary, but I really don't see the need. I'm not just being stubborn (I don't think so anyway), I am just not convinced that all of the grounding to the frame is necessary, and in the case of the 120VAC could create a problem that could prove to be unsafe.
Am I really wrong on any part of this? Althought it may appear that "my mind is made up, don't confuse me with facts", that's not the case. I'm still listening to opinions. Alright, maybe I am saying that I still need convincing of the need.