RV park wiring ?

[MFL]

I always check the park outlet, before plugging in. I recently stayed where my meter was showing 121-122.

I know that neutral to ground should be 0. I was getting a reading of 0.6, would this be cause for concern? I sprayed a little contact cleaner into the outlet, and plugged in, with no issues.

Is there a potential danger with this small reading? Would the outlet being dirty, or worn, cause this?

Thanks for any opinions,
Jerry

[Canadian_Rainbi]

wa8yxm wrote:
0.6 volt would not bother me...
Code says there is one ground but in many campgrounds there are multiple grounds. One at the pedestal itself and one at the meter.

If you drive two ground rods. say 100 yards apart.. It is not at all uncommon to find a difference in potential between them.

And for the hams among us.. Story of a YL in Arizonia.. She had a modest station 100 watts or so, and was making contacts all over when the OMs in the area who had Full Gallons could barely make it across town.. Finally hats in hand they ask her how she was doing it....

Well, I read how a good ground was important and how the ground rod(s) Should be driven in permanently moist soil for the best ground.. So I planted them in my flower garden and water them every day.

Love it!

For the hams:

Many years ago we had a member who was in kidney failure and was on peritoneal dialysis (involved running a solution into his abdomen, letting it slosh around for a while, then draining it out). At the June Field Day, which we then held in a large sheep pasture, with sandy soil, we found our antennas worked much better after all the ground rods had been treated with Frank's "drainage".

[MFL]

Thanks DrewE, good to know, for future reference.

Jerry

[DrewE]

MFL wrote:
Thanks everyone, for the replies! I did not feel that 0.6 between neutral and ground was enough to be a problem. I did plug in, and use the outlet. What concerned me, was that a small amount, could maybe turn into more.

At what amount of current between neutral and ground, would be considered unsafe to plug into?

Jerry

The NEC specifies (or at least suggests) a maximum voltage drop of 5% in the system; if you assume that is equally spread over the line and the neutral return wiring, it works out to a maximum expected neutral to ground voltage of 3V (for a 120V supply).

Note that you're measuring voltage, not current. Generally speaking, there should be no current at all flowing through the safety ground conductor. (Current flowing through the ground lead means that there's a ground fault of some sort somewhere and indicates some unsafe condition...possibly a very unsafe condition, depending on the nature of the fault.)

[nineoaks2004]

It would not bother me. Putting in traffic signals we sometimes drove 100 feet of copper clad ground rod to get that good of a ground.

[MFL]

Thanks everyone, for the replies! I did not feel that 0.6 between neutral and ground was enough to be a problem. I did plug in, and use the outlet. What concerned me, was that a small amount, could maybe turn into more.

At what amount of current between neutral and ground, would be considered unsafe to plug into?

Jerry

[CA_Traveler]

Neutrals carry current and hence have a voltage drop. Grounds aren't suppose to carry current except as a safety measure and should have 0V drop. This simply means that you may measure several volts between ground and neutral which is normal. The voltage you measured is due to some other RV drawing a load on some common portion of the neutral that you were using. That common portion of the neutral is upstream of your pedestal in the CG AC distribution system.

[time2roll]

If you unplug every RV the ground-neutral voltage will probably drop to zero.
As long as power is flowing in the shared neutral there is probably some voltage drop and you are picking that up on your meter.

[Bobbo]

Within tolerance. Don't worry about it.

[wa8yxm]

0.6 volt would not bother me...
Code says there is one ground but in many campgrounds there are multiple grounds. One at the pedestal itself and one at the meter.

If you drive two ground rods. say 100 yards apart.. It is not at all uncommon to find a difference in potential between them.

And for the hams among us.. Story of a YL in Arizonia.. She had a modest station 100 watts or so, and was making contacts all over when the OMs in the area who had Full Gallons could barely make it across town.. Finally hats in hand they ask her how she was doing it....

Well, I read how a good ground was important and how the ground rod(s) Should be driven in permanently moist soil for the best ground.. So I planted them in my flower garden and water them every day.

[WyoTraveler]

Ground are not perfect. I saw an interesting item on Utube about grounds approx a year ago. He drove in a 20' rod first and still had resistance. He drove in 3 or 4 rods to really start getting the resistance down. For amateur radio I have 4 grounding rods still not perfect for grounding my antennas. Electricians only drive in 1 rod. I suspect if conditions are dry you may measure some floating voltage. I would be more concerned if I measured 120 volts Vs .6 volts.