On 7/9/2010 6:27 AM, John Grabowski wrote:
Ok, i understand the whole panel/subpanel setup. And isolating the
neutral from the ground in the sub etc etc. Here's the question:
We've recently purchased a house (next door) and it has the typical
farm setup, (meter on the pole with a disconnect, and three wires to
the house). The difference with this one is that there is a second
panel that was added in about 1960, when they added on to the house,
which i assumed at first was just a sub off the main panel. I just
noticed today that the second panel is ALSO tied into the feeders just
outside the house and so it in effect is a second main panel. Are
there any issues with it being this way as long as each panel has it's
own pair of proper ground rods? Should the two be bonded together
either at the ground rods OR between the two panels?


I think in this case the disconnect at the meter on the pole serves as
the main panel and therefore the bonding of the neutral and ground
should take place in there as well as your ground rod connection. So you
should have four wires to each subpanel or metal conduit could serve as
the grounding conductor with three wires. At the time these were
installed three wires were permissible with the installation of a ground
rod at each building. One shared ground rod was all that was needed at
the time for both buildings.

I think that the rated life for a copper clad ground rod is 40 years.
Other materials except stainless steel is less. You should probably
install new rods for optimum lightning protection. Install two rods at
least 16' apart and have one common grounding electrode conductor with
one end going to one panel and the other end going to the other panel.
Also install at least one new rod at the meter pole.

Is there a main breaker in each panel? Are the conductor sizes the same
for each panel?

yes, and yes. at this time, everything involved is 4ga. And it's all
the same building. Actually, the panels are only about 8 feet apart,
but in different rooms.

--
Steve Barker
remove the "not" from my address to email