That sounds like no-ox on DC plant connections. You'll find after years and
years that the copper will still be shiny and new looking in the
grease-protected areas. The idea is to keep out oxygen so that the connection
doesn't corrode since the corrosion is what increases the resistance. Putting
DC plant connections together this way is still the standard today, and
probably always will be.
I have seen the no-ox used on copper-to-aluminum connections which is *bad*.
The aluminum tends to rot out, something about the corrosion inhibitor that is
great for copper is terrible for aluminum.
-Bill
> Years ago, working in telephone plant for AT&T Long Lines, I had that same
> intuitive "oh really, how can that possibly work" gut response to the Bell
> System Practices mandated procedure of slathering up massive mating
> electrical surfaces with a particular grease, about axle grease consistency,
> much thicker consistency than the automotive silicon recommended in this
> thread. The connection when active would carry almost
> 5000 amps 24/7.
>
> My intuitive mind viewed the grease as an impediment, an insulator. But the
> mate was accomplished with four bolts set to something like 50 ft. pounds of
> torque. It was then retorqued on interval until it quit loosening. I was
> always
> surprised that an ordinary voltmeter across the connection would never
> deflect the needle. Took a special taut band meter to measure the normal
> and acceptable millivolts level of voltage drop.
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