I think that wiping contacts along with adequate contact force (high enough
to bite into the other side a tiny bit) should solve this problem without a
minimum voltage and current. I've only ever seen this problem with contacts
that are either designed with arcing resistance in mind (high power
contactors) or very low contact force (like small relays, pushbuttons, and
reed-switches).

What about switches which are sealed in an inert gas?

I suspect that the problem with gold contacts is not from an oxide layer
but rather from non-chemically-bonded microscopic debris and would not
happen in a sealed environment even if it contained air. I think that the
gold oxide layer is only 1 atom thick unless you raise the temperature up
to >100C, possibly even higher.

Sean


On Sun, Jun 9, 2019 at 12:57 AM RussellMc <apptechnz@gmail.com> wrote:

> Back of brain suggests that :
>
> - With gold-gold there is a voltage above which wetting is less critical.
> - 28V is / may be above that voltage
> - 50V more so (ye olde telecom switching systems)
>
> Front of brain says that back of brain is not always trustable.
>
>
>           Russell
>
>
> >
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