"zxcvbob" wrote in message ...
Jeff Dantzler wrote:
This is not true. The right way to run a subpanel is to run four conductors:
2 hots, 1 neutral, and 1 ground. Buy a good panel and also buy a separate
ground bus for that model panel. SquareD QO is good quality.

Bond the incoming ground to the ground bus (and the case of the panel.)
Do NOT bond the ground to the neutral in a subpanel. It is okay to bond the
subpanel ground to a proper grounding rod located close to the subpanel,
but it also must be bonded to the incoming ground.

The neutral should be kept separate from the ground in subpanels. Only bond them
at the service entrance.

People will disagree what constitutes a "service entrance". To play it safe,
consider the service entrance to be the one main panel connected to the meter.

Jeff Dantzler
Seattle, WA

I think the subpanel in the original post was to be in a separate building
(a detached garage 150' from the house.) So bonding the ground and neutral
at the subpanel and having a ground electrode is correct.

If the subpanel is in another building, *and* if there are water pipes or
telephone wires or CATV (etc.) connecting the two buildings, I'm not sure
how it's supposed to be done. I think in that case you'd run 4 wires,
isolate the ground from the neutral in the subpanel, and would add a
grounding electrode.

Yes, you must run 4 wires in that case. This is the better way to do it so you have the option of
adding a metallic path to the outbuilding in the future. You'll kick yourself when you want a CATV
cable in the outbuilding and you didn't run a 4th wire with the building feeder.

In fact, here in Washington, you now must use the 4 wire method to all subpanels, even to detached
structures with no grounded metallic paths.

--
Mark
Kent, WA