Ground rod at a generator

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dwellselectric

dwellselectric

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Cape Cod, Massachusetts
Question might seem stupid I dont know. We are working on a 12kw generator and I was wondering is there a rule stating that you only have to drive a ground rod at the generator if its a certain distance off the house? IMO I think that it would be safer to drive one regardless.
 
You would only need a ground rod if it a SDS, or if the instructions with the generator tell you to install one... distance is no factor..


Out of curiosity, why do you think a ground rod is safer??
 
It is important to understand equipment grounding enables ground fault protection and grounding to earth does not.

I also receive newsletters from Mike Holt Enterprises and I have one from today ?Grounding Myth No. 2?. This newsletter ended with an obvious reminder of ohms law I = E/R. If the ground rod is relied on for a ground fault path notice this example of a 20A 120V circuit that shorts 50? out: (ground rod resistance at 20 ohms) 6A=120V/20ohms, wow not even a 15A breaker will open! This ground is simply a drain and provides NO protection for ground fault.

But this same example using an equipment grounding conductor: 1200A=120V/.1 (table 9), this breakers going to open instantaneously! Ground rods do not create a safer system for shorting or ground faults although they can provide a route for over-voltages like lightning and such.
 
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