In article uixfd.4961$9b.2815@edtnps84,
"Gordon Wedman" wrote:

Its pretty difficult to make a high voltage/current switch or
relay that does not spark but these are available in explosion proof
versions.

No, not hard at all. the Big Boys use Mercury Switches when they need
to have sparkless DC Switches. The spark is in a sealed Mercury Switch
tube, with just the wires coming out.

Me who uses Mercury Switches in Intrinsically Safe appliances....