Once upon a time on usenet Phil Allison wrote:
Mike Fleming wrote:

-------------------


There are two major issues with large mains rated toggles when used
with less than mains voltages.

1. The contact material ( often plain brass) tarnishes with a non
conductive layer. Regular use at mains voltage usually prevents
this layer building up.

2. Grease applied to the moving parts of the switch migrates to the
contacts, hardens and stops conduction.

In case 2, a squirt of WD40 often restores good operation, far as
being a mains switch is concerned.


There's a third issue specifically with switches used on DC
circuitry, which is that current flow is constant and unidirectional
and so the arcing that occurs as a contact is made and broken will
always be in the same direction and will not be broken by the
alternation of the current, only by the contact gap getting large
enough.


** Switches have *distinctly different* voltage ratings for AC and DC
currents for exactly this reason.

240VAC switches ( and relays) are normally down rated to 24V or 32V
when used with DC current of the same magnitude.

https://www.mouser.com/blog/Portals/...ig1-Switch.png

Not much relevant, however, to our present topic.

Indeed. Knowing you I opened this post expecting to see an all-capitals rant
full of medical terms, mentions of bodilly waste products and genitalia and
threats of physical violence.

Strange....
--
Shaun.

"Humans will have advanced a long, long way when religious belief has a cozy
little classification in the DSM*."
David Melville (in r.a.s.f1)
(*Diagnostic and Statistical Manual of Mental Disorders)