"the_tool_man" wrote in message
oups.com...
Hi all:

Six years ago, I built my workshop about 150ft from the house with a
100A service. I ran a four-conductor cable to the subpanel in the
shop, and kept the ground and neutral conductors isolated from each
other. I did not bond the sub-panel ground to its own ground rod,
thinking it might cause a ground loop and/or noise in the intercom
circuit bewteen the buildings. More recently, when I put in a spa with
it's own GFCI breaker, I had several people advise me to drive a
separate ground rod for it, and that I should have done the same for my
workshop. So far, I have had no issues, but I want to make sure I did
the right thing.

My searches here have yielded many debates on the need to keep the
ground and neutral bonded only in the main panel and not the subs
(which is how I did it), but nothing about the ground rod question.
Does a remote subpanel need its own ground rod or not?
Thanks in advance,
John.

Supplemental grounding gets tricky pretty fast.
Excellent choice for the 4 wire service to the garage.
Now if you drive a ground rod at the garage then the grounding conductor
back to the service must be of the same size as your service ground. If not
you COULD have a problem with an fault.... note could..
As for the spa driving another ground rod is just complicating the issue. I
assume that you took a grounding conductor to the spa, if it is connected
correctly you do not need a ground rod there.
Try reading the Soars book on Grounding. Lots of pictures and easy text to
understand.
Heck I probably do not understand what your doing cause I can not see it.