Electrical Conundrum

[Darwin Maring]

Mike Sokol has a RV Electrical Book for sale and I highly recommend it for those of you that are not electrically proficient.

[steve dunham]

The neutral conductor supplied by the local utility
q is intentionally. grounded at the source . If you examine a utility pole , you will see a ground wire running from the base of the pole to the neutral point of the utilities transformer . The neutral conductor is again bonded to ground (ground rod
,ufer ground or underground metalic water system
at the buildings service entrance along with all metallic parts of your service equipment (breaker panel ,piping ,meter socket. The grounding at the structure is a reduntant ground to the utilities ground . The grounded conductor ( neutral) and the grounding conductor (equipment ground) are not the same after you leave the service . The neutral is a current carrying conductor and the equipment ground is only intended to carry current in case of a fault .Your trailer frame is bonded to the equipment grounding conductor. not the grounded conductor (neutral) and only carries current. under fault conditions. You want the 120 VAC power to go out on the hot conductor (black) and return on the grounded (neutral /white ) conductor. The equipment ground
ground (green / bare is normally not a current carrying conductor. It is obvious from many of these posts that many do not understand the code or electrical work and as Byron said need professional help.

I hold both a journeymans and masters electrician license from the State of Minnesota plus hold a Vocational teachers license in electrical and taught code to apprentices and journeyman for over 30 years so I am not just making an uneducated guess !

[jadedave]

If you haven't taken a look at Mike Sokol's YouTube video I recommend that you do . It has some good information that is pertinent to this discussion. It also introduces simple test device that can keep you safe when entering your own or anyone else's trailer

[Mike Sokol]

Originally Posted by Bob in Mb

Since a camper is normally sitting on rubber , the frame is not an alternative ground for the supply line . If the supply line ground is faulty the only ground available will be if you contact the frame and the ground , in which case you will become the ground .

One thing I want to make very clear is that trailer jacks sitting on the dirt DO NOT ground your RV. In fact, I'm getting ready to run a few fall-of-potential tests on various ground rod configurations in my back yard, so I'll go ahead and mock up a test for the ground impedance of jack plates. I'll bet it's in the many thousands of ohms. According to the latest revision of the NEC, a ground rod needs to have no more than 25 ohms impedance to ground or else a second ground rod is required. Again, even a proper ground rod by itself really doesn't "ground" your RV's electrical system. As Steve Dunham has so correctly pointed out, the safety ground (green or bare wires) of your RV's shore power line needs to be connected between the RV chassis and the incoming service panel's Ground-Neutral-Earth bonding point with a resistance of less than 1 ohm. This is so that a hot-to-chassis fault in your RV creates enough current to trip the over-current device (circuit breaker) quickly.

I think what confuses many consumers (and some electricians as well) is that the same word "ground" is used for a lot of very different things. So the ground wire in your shore power connection doesn't really "ground" your RV chassis, it's supposed to "bond" it to the service panel's G-N-E bonding point.

Mike Sokol

[AbdRahim]

jadedave:I had a similar problem with a brand new trailer. The trailer developed a hot skin when plugged directly into the house socket after the surge protector detected an open ground and cut power to the trailer. At the time I did not realize what an open ground could be. On taking the socket out of the wall, I found current on the neutral wire, I found that the ground wire had broken off oh the receptacle. Once I restored the connection all was well. Close one. Glad it was a dry day. I always plug into a good diagnostic surge protector, whether at home or at a campground. Great investment.


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