Grounding Generator

[Raspy]

JD,

I drove two ground rods about 6' apart at the service entrance and tied them together with two #6 solid copper conductors running together that then go up into the box. Can't remember if I then pulled a ground conductor over to the main house which is about 40' away, or if I just used the Uffer ground for the house with no conductor to the main breaker panel. Just don't recall, but the inspector liked it.

I haven't gotten around to it yet, but plan to put lightening rods at both ends of the peak. These will bolt to the heavy iron skeleton and carry the current to ground through any or all of the 25 bolted down post pads. The foundation has 25 3' square pilings that go down at least three feet and are all tied together with a perimeter stem wall and footing. An 8" thick radiant slab with #3 bars in both directions on 12" centers ties the entire perimeter together into one big chunk. All of the footing an piling bars are tied directly to the hold down bolts and the heating slab rebar array. That should do it.

[redbarron55]

Back in the day when we built a plant the grounding grid that ran throughout the plant and under the slabs also was brought up at each column and cad welded to the structure.
The ground might be spread over a mile or more.
Then the MHSHA inspector would want each transformer grounded to a rod and tested with a wire run 100 feet away to a rod stuck in the ground a foot or so.
In Texas we also were tied to the ground that ran with the hi line a couple of hundred miles or more.
This because in portable equipment where 4160 volt lines were trailed behind mobile equipment sometimes had failed grounds and were dangerous in that environment, similar to the trailer issues, but very much different in scale.

[getaway1]

Most of the posts are correct in that the neutral is floating. The third wire which is the normal ground pin on a cord serves to trip the circuit breaker on your generator in the event of a fault occurring. Also never connect any generator to your house wiring circuits as even a low wattage output can back feed the power grid with enough current to kill a worker who may come in contact with the live wires. 120 volts is lethal in some conditions ! Duane

[CarlD]

Duane, It is true that you should not connect a generator to your house, unless you have a disconnect to the utility. A transfer switch serves this purpose. Also the utility has a very very low source impedance so a connected generator will essentially see a short circuit and trip immediately. One other thing, the neutral in a typical AC system is shorted to the green wire or protective case ground, so a short between hot and neutral and hot and ground have the same effect. Another interesting point is that the neutral is almost a short circuit to the hot wire. It is the resistance of the windings in the generator. The more power the generator the lower the resistance. You can see this yourself by connecting your ohm meter between hot and neutral of your generator when it is NOT running! Carl

[computerspook]

Originally Posted by Huck

Do you ground your generator when camping?

I camp A LOT with my 16 foot scamp running on a generator. Normally never ground. Never a problem.



I do ground if I am in anyway getting connected to or interacting with anything that is actually grounded. One location I don't have power, but I have cable TV available. (Long story) I ground there.

NOW I am a harm radio operator. If I am running HF or running external antennas I run multiple ground rods.