Never mess with 240V

I turned off the MCB marked 'sockets' before I worked on the socket in the aft cabin. Checked that the power was off with a mains indicator - it wasn't - and found that a previous owner had wired the socket into the water heater/calorifier circuit........... A good reminder, to me, to always check.
 
I managed quite a nice shock from 12 VDC once - standing in salt water next to a ski boat and tightening the battery positive terminal with saltwater dampened finger with a recent shallow cut. The battery negative was of course connected to the engine block and hence to the prop shaft. Agree entirely with rings and spanners near batteries - a hacksaw works well too.
 
TSB240 said:
Always check with a meter.... It is a requirement for all qualified electricians to do so if working on any exposed high voltage conductors.

The only time I didn't I had serious shock off a cable that I had disconnected at both ends....
Induced voltage. On many marinas your shore power could well run alongside someone else's for some distance. Just saying your advice to unplug is not a safe working practice for a professional so why be a dead amateur.
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I did read many years ago about an ingenious chap who lived very close by to HV transmission pylons, he set up what looked like a couple of washing lines in his garden parralel to the HV lines and was running equipment from the current produced, iirc he was prosecuted for stealing electricity
 
I spend a "pleasant" couple of hours undoing the dozen bolts on my flexible coupling. They need an open ended spanner and an Allen key. The top of the battery is such a convenient place to put the tool you aren't using...

No, actually I didn't, but I came close. It may have been this thread that gave the little nudge that it could be a bad idea :)
 
chrishscorp said:
I did read many years ago about an ingenious chap who lived very close by to HV transmission pylons, he set up what looked like a couple of washing lines in his garden parralel to the HV lines and was running equipment from the current produced, iirc he was prosecuted for stealing electricity
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"Trivia On"...........

Walking around under HV lines with a fluorescent tube used to be quite popular 'fun' . The budding Engineers among us constructed resonant coils to greatly improve the range.
It was also known for people to 'extract electricity, the property of the Postmaster General' by drawing a small current from telephone lines: as long as this was below a certain threshold the exchange would not see it as 'off-hook' . :D
 
penberth3 said:
Also steel watch straps!
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Too true, I knew a ' pro electonics expert ' who when working on his car got his steel watch strap between a battery terminal and the car body - the deep scarring burn looked jolly painful, still he'd been rotten to me as an alleged friend so I can say ' karma really does work ! ' :encouragement:
 
Following a spate of motorcycle battery thefts by "lampers", I bolted an aluminium plate over the top of my battery, under the seat. The first time I sat on it, the plate buckled and shorted out the battery, which promptly exploded. Fortunately the explosion was contained within the motorcycle, otherwise the likely consequences don't bear contemplation. But regarding the dangers of mains shocks, I always have a neon screwdriver/tester handy. It only takes a second to test, which is about as long as it takes to die. And they're so cheap, it's madness not to have one.
 
When I worked on power electronics, if we wanted to be sure a supply was dead and stayed dead, we shorted it out.
The walk to the tool room to get a new end ground on your screwdriver was a good cooling off period, for the student engineer as well as the No 12 screwdriver.
 
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