generator grounding to truck

[wolf146]

I never thought of this issue until I read the thread about generator safety. Here is the scenario. I have a 2800 Yamaha i ( metal frame) connected with a chain to the frame of my Toyota pickup truck. If there were to be an electrical malfunction on the generator and it is attached to the metal frame of the truck could I get a dangerous shock if I were to touch the frame of the truck? Or is the mass of the truck sufficient to provide a proper ground?
wolf146

[Protagonist]

Originally Posted by wolf146

I never thought of this issue until I read the thread about generator safety. Here is the scenario. I have a 2800 Yamaha i ( metal frame) connected with a chain to the frame of my Toyota pickup truck. If there were to be an electrical malfunction on the generator and it is attached to the metal frame of the truck could I get a dangerous shock if I were to touch the frame of the truck? Or is the mass of the truck sufficient to provide a proper ground?
wolf146

Mass of the truck doesn't really matter. The tires insulate the truck from ground. If you're grounding to the truck, and you touch the truck, you're the path to ground, and you'll get a shock.

A Yamaha EF2800i inverter/generator has a ground terminal on the control panel, just to the left of the bottom AC outlet. Should be a little symbol beside it that looks sort of like a downward-pointing arrow. Connect an insulated wire from this ground terminal to a metal stake driven at least a foot into the ground. Keep the wire as short as you can and still reach. An automotive jumper cable should do nicely for this purpose. The owner's manual says 0.005 inches diameter per amp the generator produces, so about 12-gauge wire for a 20-amp generator, 9-gauge for a 30-amp generator.

Connecting the ground terminal to a ground rod ensures that you're not grounding through the metal frame of the generator, and therefore not through your truck, either.

[wolf146]

Originally Posted by Protagonist

Mass of the truck doesn't really matter. The tires insulate the truck from ground. If you're grounding to the truck, and you touch the truck, you're the path to ground, and you'll get a shock.

A Yamaha EF2800i inverter/generator has a ground terminal on the control panel, just to the left of the bottom AC outlet. Should be a little symbol beside it that looks sort of like a downward-pointing arrow. Connect an insulated wire from this ground terminal to a metal stake driven at least a foot into the ground. Keep the wire as short as you can and still reach. An automotive jumper cable should do nicely for this purpose. The owner's manual says 0.005 inches diameter per amp the generator produces, so about 12-gauge wire for a 20-amp generator, 9-gauge for a 30-amp generator.

Connecting the ground terminal to a ground rod ensures that you're not grounding through the metal frame of the generator, and therefore not through your truck, either.

Thanks for the answer. How, then, do the generators in motor homes get grounded? wolf146

[Protagonist]

Originally Posted by wolf146

Thanks for the answer. How, then, do the generators in motor homes get grounded? wolf146

Different situation. In a motorhome, the installed genset powers apliances that are built into (or at least plugged into) the motorhome, and there is a ground bus connecting the genset ground to the appliance ground. Nothing is grounded to earth in this case, and the motorhome chassis can safely act as a common ground.

In your case, the generator is on the truck, and may be plugged into appliances that are not grounded to the truck or to the genset. The truck is not a common ground unless everything energized is grounded to it, and so you need to attach the ground wire from the generator to a common ground, typically the earth.

[wolf146]

thanks for that explanation. I appreciate it. wolf146

[dznf0g]

What if you have your umbilical plugged in? The truck and the trailer then share a common ground. (or hitched for that matter)

[TG Twinkie]

I think you are confusing the common/ground which is part of the 12 volt DC circuits in your TV and trailer with EARTH ground which is part of the 120 volt AC circuit.
While the common/ ground and EARTH ground are both connected to the trailer frame, they are two different animals.
Somehow back in the stone ages someone started calling the return side of a DC circuit "ground". It is in fact the "common" return path for all devices on that DC circuit. It has nothing to do with ground. But it's too late to fix it now.

[dznf0g]

Originally Posted by TG Twinkie

I think you are confusing the common/ground which is part of the 12 volt DC circuits in your TV and trailer with EARTH ground which is part of the 120 volt AC circuit.
While the common/ ground and EARTH ground are both connected to the trailer frame, they are two different animals.
Somehow back in the stone ages someone started calling the return side of a DC circuit "ground". It is in fact the "common" return path for all devices on that DC circuit. It has nothing to do with ground. But it's too late to fix it now.

DUH! brain fart!

[Protagonist]

Originally Posted by dznf0g

What if you have your umbilical plugged in? The truck and the trailer then share a common ground. (or hitched for that matter)

Not necessarily. <edit>TG Twinkie beat me to it while I was composing this.</edit>

Anyway, I got the information about the Yamaha generator's ground terminal straight from a downloaded copy of the Yamaha 2800i generator owner's manual.

Based on the owner's manual for the generator that wolf146 owns, the only recommendation I can make is, connect the ground terminal to a metal stake driven into the soil, even if you don't think you need it.

By the way, wolf146, is your username an astronomy reference, by any chance?

[wolf146]

No. Wolf is short for Wolfgang, my first name ( German) and 1 is the month I was born and 46 last 2 digits of the year I was born. wolf146

[Protagonist]

Originally Posted by wolf146

No. Wolf is short for Wolfgang, my first name ( German) and 1 is the month I was born and 46 last 2 digits of the year I was born. wolf146

Ah. Sorry. One of my coworkers is an astronomy buff, and happened to mention Wolf-Rayet stars a few days ago; these stars all have catalogue numbers like Wolf 359, etc. So your username rang a bell.

[Wazbro]

Originally Posted by TG Twinkie

I think you are confusing the common/ground which is part of the 12 volt DC circuits in your TV and trailer with EARTH ground which is part of the 120 volt AC circuit.
While the common/ ground and EARTH ground are both connected to the trailer frame, they are two different animals.
Somehow back in the stone ages someone started calling the return side of a DC circuit "ground". It is in fact the "common" return path for all devices on that DC circuit. It has nothing to do with ground. But it's too late to fix it now.

Actually in a DC circuit electricity flows from negative to positive, everything is just wired like it goes the other way. But your right it's too late to fix it now.