On 8/22/2013 2:58 PM, Charlie Gallo wrote:
Well, there was some arcing at the ground block in the past, so I lifted the
coax to slip on the ferrites, and the voltage is still there, but the current
is low enough the ground takes care of it - ground clamp was a bit loose to,
cleaned and tightened that
In normal (non-fault) operation, grounds should NEVER carry AC currents
greater than a few mA. Likewise, the voltage between grounded objects or
conductors should NEVER be greater than a volt or so. If there is
voltage or current greater than these values, SOMETHING IS SERIOUSLY
WRONG. The legal limit for leakage current (current on the green wire)
in a branch circuit is 6 mA.
Always consider at least these four possibilities, and test to make sure
that none exist.
1) An AC outlet may be wired with conductors reversed.
2) The equipment connected to the remote cable (in this case, the CATV
cable) has a serious AC fault condition (perhaps that mis-wiring
problem, or a very major grounding or bonding error).
3) Your equipment may be defective or have a fault condition.
4) There may be a problem (fault or mis-wire) in the mains power system
supplying you or that remote equipment.
One of the most important pieces of equipment we should all own is a
clamp-on AC ammeter that can be set to read small AC currents. This
generally requires a low current scale where the top of the scale is no
more than about 5A, and a 1A scale is better.
To use a clamp-on ammeter, we must be able to clamp it around a single
conductor. Inside the breaker panel, that's fairly easy, but to measure
current anywhere else (like at an outlet), we need a simple breakout
cable. I have made breakout cables by cutting away a foot or so the
outer jacket of a short AC extension cable, exposing the individual
conductors. I plug the cable into the outlet and the equipment into the
other end of the cable.
73, Jim K9YC
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