Re: High voltage power resistors

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Mike Harrison by way of Terry Fritz <twftesla-at-qwest-dot-net>" <mike-at-whitewing.co.uk>

Incidentally, while we're on the subject of power resistors, a warning
arising from an 'incident' I had recently......

When using those gold metal-clad resistors at high powers, it's
tempting to assume that if you bolt them to a big enough heatsink,
they can dissipate an almost infinite amount of power, if only for a
short period of time. 
However when seriously abused, they have a potentially dangerous
failure mode - the ends can fly off at a frightening speed - I had one
come off, tearing off the wire that was soldered to it and ricocheting
off the ceiling - I never found it. Fortunately it just happenned to
be pointing upwards, not towards me. A couple of loud cracking sounds
immediately preceded the explosion.
There is also a secondary hazard if used at high voltage - after the
explosion, there was a 2-foot trail of wire (the original resistance
coil) hanging out of the dead resistor - this could act like a Taser,
connecting HV to things that you really don't want it connected to!