[RFI] Power Line Bypassing
jim at audiosystemsgroup.com
Mon Feb 14 23:24:11 PST 2011
On 2/14/2011 8:16 PM, Dale Svetanoff wrote:
> Jim Brown raises excellent points in his post, below, but I can
> tell you that if the problem were with my well pump system, I'd have a very
> difficult time doing the by-passing in the most effective manner.
Sorry, I guess I didn't answer clearly enough. I did NOT suggest
bypassing as a solution. Rather, I suggested 1) correcting any power
wiring problems; and 2) adding a common mode choke at the noise source.
For a well motor deep underground, the choke should go as close as
practical to where the wiring that pump comes above ground. But, as you
note, it's unlikely that the well pump underground is a variable speed
motor, and is unlikely to be the source of the noise.
To answer Chuck's question, NO, bypassing at YOUR panel is unlikely to
be a solution, for the reasons noted in my earlier post. I have a well,
roughly 100 ft deep, with both a pressure pump and a purification system
above ground. It's possible that either that such a pump or purification
system could be a noise source. Again, make certain that the power
wiring is correct, and if there's still a problem, add a common mode
choke, following the guidelines in my RFI tutorial.
BTW -- these potential power wiring problems are governed by Electrical
Building Codes, which carry the force of law (your local building
department). The National Electric Code (NEC) is a model code written by
a consortium of very good engineers as a model, and has been adopted by
most local governments. Wiring that violates this codes is both ILLEGAL
and UNSAFE. These are not dumb beaurocracy, or government meddling, they
are based on very solid principles of electrical safety. The safety
hazards include lightning, fire, and electrical shock (which can cause
death). Your friend should make this clear to his neighbor.
73, Jim Brown K9YC
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