Grounding Generators?

[usmcveteran]

Do you need to ground a generator? What is the best way to do it? Is it ok not to ground if it's going through transfer switch? Would that use existing house ground?

[Norm DeGuerre]

grounding_port_generator.pdf

[usmcveteran]

So yes I need a separate grounding rod?

[Norm DeGuerre]

if the generator has 120v duplex outlets that are bonded, then yes
nobody ever does this on a construction site tho

[Norm DeGuerre]

the rod is so the generator can never have a higher potential to ground if you touch it

[usmcveteran]

As soon as it's plugged in then isn't it already grounded? The ground from plug goes to grounding bar breaker box so grounding at generator as well won't cause double ground issues?

[WARFAB]

No idea what the technical reasons are, but the little pictogram instructions on my generator say to ground it so I did. I found a piece of steel rod another 12" long and just used that. Hammered it into the ground every time we took the generator out to use. It's not hard to do, so I didn't bother questioning it.

[Norm DeGuerre]

As soon as it's plugged in then isn't it already grounded? The ground from plug goes to grounding bar breaker box so grounding at generator as well won't cause double ground issues?

if the generator has 120v duplex outlets that are bonded, then yes

You have a safety Standard applicable to portable generators
and, yes, theoretically it would be grounded thru the home's ground loop, however the resistance of the generator frame to ground, and the resistance to the house ground are different, causing a voltage potential

double ground issues ..??
correct..
if the house service was active, and the grounding failed, again, theoretically the whole of a neutral/ground (bonded) current could travel to ground thru the genset hook=-up wire, causing it to burn
but
the generator is running because there is no main electric