Arfa Daily wrote:
> I too have a thin plastic cable in there. There was a good reason that
> I changed it apart from the intermittency. Over the years, it has had
> a lot of 'half-arsed' repairs done to it. I'm sure if you have one,
> you know exactly what I mean. It's half past two, and the guy is
> coming to pick up his amplifier that you have assured him will be
> ready at half past four, and the bench light starts going on and off
> ... Well, a long time ago, some silicon sheathed heat-resistant wire
> had gone into the lampholder, and been joined to the feed cable (via
> the pressel switch bypass ...!!) with a bit of plastic choc-bloc. Yes,
> I know, but I didn't have a ceramic one to hand.
Ooo shudder !
> Anyway, it had been fine until I started using these small very hot
> bulbs in it, whereupon the nylon insulation on the bloc had crisped
> up. Well, a couple of weeks ago, I had one hand on the (earthed)
> chassis of an amp I was working on (no, it wasn't plugged into the
> bench isolation tranny as it should have been !) and I grabbed the
> Anglepoise shade to pull it into a more convenient position. A
> microsecond later, the air turned blue as a stream of profanity flowed
> from my mouth ...
I must admit I don't plug mine into the isolated side ! Doesn't/didn't
yours have an earth connection then ? Mine does and had one from new !
> The crisped up insulation on the choc-bloc had left a mains leakage
> path to the metal shade. I decided there and then that no such thing
> was going to happen again, so I have now rewired it with a thin
> three-core cable, and grounded the metalwork to mains earth, via the
> earth connector on the brass lampholder. Silicon sleeving has also
> been fitted to the wire ends in an effort to proof them at least some,
> against future heat problems.
I've seen electric heaters repaired with those plastic choc-blocks put
in them. I once had an old lady ask me to look at one. She said it
smells funny and there is something dripping out of the back. The
plastic surround had almost compleatly gone and the connections were
hanging in mid air. I had a go at the guy who repaired it and was
un-politely told to sod off........ Sadley there weren't the consumer
protections in those days !
> I've got to admit that the shock I got from the setup was a bit of a
> wakeup call, as it's often the case that your forehead brushes agains
> the lamp shade, as you try to stick your head inside some recalcitrant
> item that's on the bench for repair. At least now, if there should be
> any future leakage issues, it should just whack the RCD out.
>
> Arfa
Its a good thing you didn't touch it with your forehead ! I can't
imagine the possible injury it could have caused. At least it
shouldn't happen again.
--
Best Regards:
Baron.
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