We
were chattering about Safety Code Six a couple of columns ago … and while it’s
still fairly new and it’s of interest to Industry
You
are alone at a transmitter site that has a surge suppression system installed
at the main distribution gutter, i.e. after the main hydro disconnect, but
unable to be de-energized on its own breaker or cutoff switch. There are six status lights on the front of
the suppressor box, and two of them are extinguished, indicating that an
internal fuse on one of the three phases has blown. You know that you should not replace a fuse
while the circuit is hot, and you know that you should not work on this by
yourself. But no one else is around
right now, and to kill this circuit would take the station off the air, so you
really should come back late at night, and you’d rather not have to do that, so
you figure you’ll just be extra careful, and you’ll ensure that you don’t
become part of the circuit.
But
what you don’t realize is that the fuse blew in the first place because the
MOV’s inside the suppressor module have failed destructively by shorting, and
when the fuse is replaced, the replacement fuse instantly explodes in your
face, causing second and third degree burns there and on your arms. As you stumble, dazed, out of the transmitter
building into the open air, the door slams shut behind you, locking you outside
with your keys inside. But you are lucky
to be alive.
An
air conditioning technician was killed in
You
are alone at the transmitter site. You
are having a pesky problem with the power supply intermittently
overloading. In order to get a better
look, you defeat the interlocks and leave the back door wide open while the
transmitter is operating. After a while,
you get braver, and start carefully poking around inside the cabinet.
You
wake up lying on the transmitter building floor. You have no idea how you got there, or how
long you’ve been unconscious. The
transmitter is still happily running, with the back door open. Eventually, much later, you notice small
burns on your back and one of your feet.
You, too, are lucky to be alive.
You
are a chief engineer at a transmitter site with your assistant, and you have a
nasty transmitter problem. You
eventually are able to solve it, but many hours have passed, and you are very
weary. Now you’re just cleaning up the
transmitter to place it back in service, and have finished dealing with the
high voltage circuits, so you feel pretty safe.
Unfortunately for you, you’ve become tired and careless, and although
you don’t contact the high voltage, you do come in contact with 120 VAC. In your weakened condition, your heart
stops. Your assistant is able to summon
help and apply artificial respiration until help arrives, but you never
completely recover your faculties, and never are able to work again.
These
accidents all happened more or less the way I have described them. And they all happened to experienced
technicians, not newcomers to our trade.
Let’s continue this theme next month.