Need to ground RV power pedestal progress report

[charliem]

[
How about +4 dBu 

Never heard of dBu so I looked it up. Open circuit voltage into an unspecified impedance? Real men work at 50 ohms 

[Merlin]

BTW, in the world I come from anything above 0dBm is high power 

How about +4 dBu 

BTW: I might have a sponsor that will allow me do a few seminars about RV electrical safety and hookups at campgrounds on the mid-atlantic coast. Do you guys have any rallies or meets this summer or fall? I'm in Maryland and normally do seminars as far south as SC and as far north as NY. And I go as far west as Ohio and Indiana. Any suggestions?

Mike, We do have meetups that are great fun. It's a good crew on here. However, our meet ups are relatively small affairs. The one last summer in OR was about 40 people total and the one this summer in ME is about half that. We keep track of those in a separate thread on this forum: Aluminum Camper Gatherings. If ME is not too far, check out the details of the August 5-6 meetup on that thread. I may try to organize one in the Midwest at a campground on the Great Lakes in 2018. I'm sure there would be lots of interest in RV electrical safety wherever you go!

[FastEddieB]

I had some time today and replaced the ROMEX with 10GA SOOW on the temp pole run. Will take care of the shed lead next time up.



Also jumped the two 50A legs, which did energize the 30A receptacle and I confirmed the correct voltage across each lug. Will mark it "20A MAX" when I have my labelmaker with me.





Ran the ground wire out from the ground bus, but waiting to sink the ground rod to hear back from the contractor to verify there's nothing running underground where I plan on putting it.



Mike says it should now pass muster if an inspector happens to wander by!

[FastEddieB]

Flew up today for the finishing touches:



Done!

[Diversteve]

Your place looks like a slice of heaven.
I bet it is hard to leave!

[FastEddieB]

Your place looks like a slice of heaven.
I bet it is hard to leave!

It's very nice, but our home in N GA is a little slice of heaven as well!


Have not had a chance to power the RV from our RV pedestal yet. Should have a good solid 20A at the 30A connector, with large gauge wires running from the temp pole to the pedestal. That should be enough to power the air conditioning if nothing else is running, and its easy to throw the breaker for the RV's converter to take that load off as well.

Question...

If someone snuck in at night and swapped a 30A breaker for one of the 20A breakers at the temp pole, would that present a problem? The only "bottleneck" I can see would be the 20A outlet and 20A plug at the temp pole. The rest of the wiring is certainly up to 30A service with no problem, and the temp pole is fed with 100W service.

[Merlin]

If someone were to wear black clothing and use night vision goggles so a flashlight was not needed, it seems doable. You've ID'd the "bottlenecks".

[FastEddieB]

If someone were to wear black clothing and use night vision goggles so a flashlight was not needed, it seems doable. You've ID'd the "bottlenecks".

Thanks. I just contacted NinjasRUs for their rates.

I don't anticipate the bottlenecks being an issue if I try to keep the draw anywhere near 20A, which I think I can do.

[DavidM]

You should be entirely legal, code wise with a 20A breaker feeding properly sized wire and a 20A outlet at the far end. Lot's of things can happen to make legal electrical stuff illegal, but i wouldn't worry about it.

David

[FastEddieB]

Update:

Camped at the property Thursday night, first time with power to the pedestal.

A friend suggested that I just remove the 50A breaker and move the 30A over one slot:



Both share the same leg now, so jumper required.

After testing the 30A outlet, plugged in and viola! - works as intended.



Did not need air conditioning, but meant to try it out and forgot. If the 20A breaker at the temp pole trips, I'll consider replacing it with a 30A single-pole breaker.

Also drove in and hooked up an 8' ground rod at the RV pedestal.

I now just need to install blanking plates for the two empty slots. Thanks again for all the input.

[FastEddieB]

Good news!

We drove from Kitty Hawk to our TN property yesterday and camped last night. We were tired and waited until this morning to hook up to our pedestal.

Air conditioner started up and ran just fine. As an experiment I also ran the microwave at the same time and nothing tripped. We may be at the limits of 20A sevice to our 30A receptacle, but not overtaxing it as long as we don't run everything at once.

Thanks again for the guidance!

[oldthreadreviver78]

The National Electric Code requires one and only one ground located at the power source, which in your case is the power company supplied power panel. You will not be in compliance if you install another ground rod downstream of that one.

Close! What you're thinking of is NEC 250.24(A)(1) where only one neutral to ground bond is allowed. You indeed can have multiple ground rods or GEC's in a system per that section and NEC 250.32 which outlines requirements for a grounding electrode system and bonding of grounding electrodes.
Ground loops cause hell for low voltage systems like paging amplifiers, but the point of a ground is strictly for safety of life and property when something goes wrong.
It's absolutely OK to install a ground rod at an RV pedestal, an automatic standby generator (if neutral is bonded to frame, check installation guide), a telco demarc, hot tub - anything like that. Give that fault current a short path ground.
Then also remember the amount of current flowing through the line leg should equal the amount of current flowing through the neutral wire for your load (true for line to line but let's focus on N and G) - this is where the single Neutral to Ground bond rule comes into play. If that current finds another path in your system to flow, best case you have weird problems, worst case a fire.
There's a fantastic video on Youtube from Dave Gordon called Open Neutral that helps visualize where the current is going in a two leg + neutral system. The video ID is LJvyb_WujZg.
Also countless Youtube videos about the N-G bong and why it's important, what is a loaded neutral, etc.