Quote:
Originally Posted by FW28z
I am going to have to disagree here.
I have an older copy of the NEC, so forgive me if my information is not up to date....
In conclusion, ask yourself the following:
1. are their shorepower pedestals in campgrounds that are mis-wired (hot and neutral reversed)?
2. is it an unsafe condition to operate a RV in this situation whereby the potential exists that you have an ungrounded current carrying conductor that is not protected with a breaker?
3. does the NEC permit wiring techniques (by breakering hot and neutral) to prevent such a safety issue (see NEC 380-2 Exception 1)?
This is still a huge safety issue in my view.
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The marine industry has it's own set of rules, and definitely more safety issues than an RV on the dirt. The most notable danger being gradient voltages extending out from freshwater docks where a boat's ground system has become energized. That gradient can extend out dozens of yards and paralyze any swimmers in the area, causing them to drown without actually being electrified. RV's will have a hot-skin condition with a compromised grounding system. Certainly still dangerous, but only with direct contact.
But to your point about Ground-Neutral Bonding, remember that an RV's circuit breaker panel is treated like a sub-panel in a house, NOT a service panel. So the RV is depending on the pedestal outlet to provide the G-N bond. And the pedestal is also treated like a sub-panel, with its Neutral floated from the Ground, and dependent on the main service panel to provide the G-N-E bond. The reason for this is that the EGC grounding conductor must never carry load current, ONLY fault current.
So can pedestals have their Hot and Neutral wires reversed? Certainly it's possible, but definitely a code violation. And while it appears dangerous, by itself will not cause a hot-skin condition. The hot wires in the RV will now be a ground potential, and the neutral will be at 120-volts, but because the ground is isolated from the neutral, it won't leak current to the chassis. I'm advocating a yearly (or at least semi-yearly) test of all campground and marine pedestals for proper voltage, polarity and grounding. But that's a long way off.
As far as disconnects, from everything I've read in the most recent NEC code, you can only switch the neutral (via a circuit breaker) if ALL conductors are switched, including the EGC (Equipment Grounding Conductor - commonly called the safety ground). So you would need a 3-pole switch, not just a 2-pole switch. Neutrals are not Over Current protected in residential, commercial and RV wiring because of the danger of an neutral opening up and allowing the internal wiring to bias to 120-volts, including the internal neutral conductors.
BTW: The latest NEC is available online for free, so that's one resource where you can continue your studies. But I'm working with an NEC sub-commitee right now on RV grounding issues, and there's never been a discussion about adding a double breaker to open the neutral. Not going to happen, and if you do it yourself you'll be in violation of the RVIA build codes.
Again, the marine industry is different so you can't apply those rules to an RV situation. But I don't see where adding OCP to the neutral conductor will add any safety at all to an RV. Under what situations do you see it being safer?
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