On 2013-07-30, Jim Wilkins wrote:
"DoN. Nichols" wrote in message
...
On 2013-07-29, Jim Wilkins wrote:

He didn't stay long, the rumor was that he touched a large exposed

[ ... ]

my machine blackened from the explosion.

Ouch! Good day to be out sick or otherwise out of range.

Touched it with *what*? Something metal to vaporize -- or was
the black from carbonized employee?

The story I heard was that he and another newbie engineer were
attempting to find the proper phase rotation by touching the live 480V
cables to the input terminals while squatting on the floor, and one
lost his balance.

Ouch! Really asking for trouble.

I don't remember who said that or may have seen it
happen. Luckily it wasn't me, though I probably would have found a
reason to be on the far side of my machine or taken a break.

Another time a tech was checking a faulty SCR trigger circuit on the
machine beside mine, grounded the scope probe to the SCR cathode and
turned on power. The probe cable exploded in midair before the breaker
could trip. Fortunately I wasn't injured and his weren't serious.

An argument for a differential plugin for the 'scope -- and the
intelligence to know that it was needed. :-)

Enjoy,
DoN.

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