Grounding and Noise

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megloff11x

Senior Member
It seems that if I turn my back and someone has an electrical noise issue, they immediately take the Dr. VanHelsing approach of pounding a spike into the ground, usually a piece of rebar or whatever is handy in the scrap metal pile out back (the rustier the better). Then they affix a piece of wire to it - bonding implies a solid electrical connection with a properly sized conductor so I can't use that term here. Then they affix this wire to their widget, sometimes with duct tape (Red Green would be proud). And they are greatly disappointed when it does nothing or makes it worse.

Has anyone EVER applied this Vampire slaying method of electrical noise reduction and had it work?

The approach I learned is that the electrons want to get back home. Thus you need to create a low impedance path to the return of their generation point. At higher frequencies, round wire is an inductor so you need specially shaped conductors. The newer snazzy VFD cable has multi-layered jackets and conduit to provide all frequencies a low impedance return. You're dealing not with "power current" so much as electrons trying to align themselves to oppose incoming or outgoing fields, and anything that helps them move quickly, and taps into reservoirs of electrons (like big metal things) in a manner that lets you draw or dump to the well quickly, will help the best. The ground beneath our feet is a big reservoir but it's relatively slow to draw from.

On one rube goldberg device, wired by scientists, I almost needed a machete to remove the ratsnest of "grounds." And I thought we had concrete termites with all the holes for rods in the floor.

I've also had seconds call over the issue of "grounding" the shield of shielded cables at both ends or just one.

What can we do to stop Dr. Van Helsing's disciples?

Matt
 

jtester

Senior Member
Location
Las Cruces N.M.
megloff11x said:
......What can we do to stop Dr. Van Helsing's disciples?

Matt

I've seen the same thing when dealing with stray voltages. Bare copper wire tied to everything in sight with stainless steel clamps, and then run to numerous ground rods. It doesn't work either.

Education is the solution, but in my experience, many individuals resist that. "It was good enough for my dad, it's good enough for me." Or "I've done it that way for years." Or "you're an engineer, you don't understand the field."

I think the best bet is to learn to live with them.

Jim T
 
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