On Sun, 15 Nov 2009 17:52:46 -0500, Tony Sivori
wrote:

I recently acquired a small portable back up generator for nuisance
outages. Only paid $200 new. It is 2500 watts continuous, 3250 surge rated
and no 220 volt outlet, so I won't be hooking it up to a transfer switch.

Even though I'm going the extension cord method, I decided to properly
ground it, and use an inline GFI and surge protector. I'm willing to risk
using a back up computer with it, and I am hopeful that a surge protector
might clean up the "dirty" generator power.

Now the problem. I drove an 8 foot ground rod into typical soil, used a
correct copper clamp (nothing improvised), and connected the rod to the
generator ground lug with a single strand 12 gauge copper wire.

Trouble is, the generator outlets still tests as ungrounded.

I immediately suspected miswired outlets on the generator. So I tried
checking the resistance from the power receptacle outlet ground to both
the generator frame and the generator ground lug. Both tests resulted in
zero ohms of resistance. I'm thinking that would eliminate miswiring on
the generator as the cause.

I then removed both ends of the ground wire connection, checked and
reconnected them.

Same result, tests as open ground with a three prong plug in tester. I
also tested the tester, and it shows grounded outlets in my house as
properly grounded.

I checked the resistance from the generator end of the ground wire to the
ground rod itself. It was also zero ohms.

So it seems to be a case of it has to work, but it doesn't work. Any
suggestions are welcome.

You may have high resistance soil, and need more than one ground rod.
Code typically calls for three, wired together.