[Arny Krueger]

"Richard Crowley" wrote in message

"hank alrich" wrote ...
Richard Crowley wrote:

How good are the green-wire grounds?

I don't know. If I measure between contacts at the quad
box or power strips I get:

120.5 V hot to neutral
0.5 V neutral to ground
6.4 V hot to ground

If "6.4 V" is not a typo, it seems like a BIG PROBLEM.

It suggests to me that ground is floating.

The Neutral (white) and Ground (green) are supposed to
be tied together somewhere back around the breaker box.

Big time!

Even if this is fed from a 3-phase power drop from the
utility, there should be virtually zero V between neutral
and ground, and the voltage between hot and neutral
should be the same as between hot and ground.

A fraction of a volt diff wouldn't bother me, but they should be very close.

This may be an indication of serious/dangerous problems
with the power wiring. I'd seriously consider telling
them to get a licensed electrician to correct/confirm the
wiring before proceeding with any signal wiring
debugging, etc.

Agreed.

If it were a private residence we could discuss debugging
processes for fixing (or at least identifying) this
problem. But since this is a public building, it would be
inappropriate to suggest anything but legal work by a
licensed electrician.

Agreed. But, back in the real world...

Should I run a long lead from the ground rod to the
closet and read Ohms
for that link to see if the building wiring actually
connects the greens
properly to the stake?

I'd put a voltmeter between the two, first.

I would defer to a licensed electrician. You may have
identified a dangerous mains wiring problem.

That, too.

Does the system hum with an isolated source (an MP3
player, etc.)?

Lots of hum when Onkyo fed by TiBook running on power
supply.

But that happens to most of us. The power supplies on
laptop computers are notoriously reliable sources of
noise.

So is just about everything else, these days.

BTW, know what the power supply on a Microtrack is? Switchmode.