Lets put mains on to the pins of a plug!

[alan_m]

He's generating low voltage 3 phase AC from a water powered turbine, rectifying it to 24V DC and then using a inverter to generate 110V AC (this is the USA). This is then wired to a standard USA plug which he plugs into a wall socket - almost the equivalent of having an extension lead with a main plug on each end :)

He doesn't know much about electricity but his mate wired it to "code".

He uses a shop vac to start his generator by introducing a vacuum in the pipe which is then maintained allowing water to flow faster than it would with just a simple syphon arrangement.

[Tricky Dicky]

I cannot see how that ?Jesus? lead from the inverter to the socket could possibly be code.

Richard

[Brian Gaff (Sofa]

Does he have a death wish or merely wants to burn out parts of his wiring perhaps?

It sounds like a lazy persons test idea. Its not going to actually cost much to put the right switching in place between the mains and his other system which we do hope is protected for overloads. grin.

Brian

[Brian Gaff (Sofa]

Well anyone ever been appalled by the standard of wiring bodge ups in Spain I have. Its a wonder most British tourists have not been electrocuted. Brian

[Tim+]

It?s still just a simple syphon. He?s just using the vacuum to clear the air-lock to get it flowing.

Tim

[Chris Hogg]

Yebbut as you point out, it's America and 110 volts, so AIUI it's unlikely to be lethal. Not to be repeated in the UK with 240 volts though. AIUI lot of UK kit used by builders is rated 110v via a step-down transformer, for just that reason: it's not lethal.

Not sure about that. Yes, the shop vac starts the syphon, but then he turns it off and the syphon continues. Just like any other syphon, only with an 8" pipe it would be a little difficult to start the syphon by putting your mouth over one end and sucking! But I see no reason to think that the flow is faster because he uses the shop vac. He ends up with a simple syphon when the vac is shut off.

[NY]

Kit used by builders is not only 110 V, but the supply is fed by a split winding transformer, with the centre tapping earthed, so the power lines are at + and - 55 V wrt earth (*). You still get a 110 V shock if you touch the two terminals, but if you touch one terminal and earth (possibly the more common "failure mode") then you only get a 55 V shock.

(*) OK, I know it's AC, so "+" and "-" don't really mean anything.

[Harry Bloomfield, Esq.]

NY presented the following explanation :

Not +ve and -ve, it is ac.

[Andrew]

Not to mention the people who have been killed by CO poisoning or fallen off balconies because Spanish balconies are very low.

And you should see the typical arrangement for instant showers in South America.

Andrew

[Tim Streater]

I see his turbine is at the top. Presumably, since he's doing a syphon he's relying on the low point being no more than 33 ft or so below the top (which it is in his case). I was minded to wonder whether the setup would be more efficient if he had the turbine at the bottom instead. I suppose his setup is simpler because he doesn't have to arrange, at the top, that the take-off pipe stay below the water surface level until it can start to drop vertically.

Nice idea about the tennis ball - which is chaos theory in action.

It may be that Yank homes with their cheeseparing 110V can get two phases supplied to their house quite easily and his arrangement may somehow disconnect the phase he's feeding into. What is worse though is that he's shoving 5A or so through that shitty two-pin socket. With their notoriously flimsy plugs/sockets, there will be some heating effect there that he may need to keep under obbo.

[Nick Odell]

You'll be relieved to hear that it's becoming almost impossible to buy one now - at least in the Southern Cone. After a few horror-stories of my own with those things I rather fancied buying one to bring home but couldn't find a new one for sale. My plan had been to fit one in my own shower and with my dark sense of humour leave exposed wires twisted together and position the knife switch directly under the spray. Nothing would have actually been connected - the real hot water would still have come from the combi boiler as usual.

Nick

[NY]

Sorry, I thought I'd covered that in my asterisked footnote. I know it's AC. What I meant was that the two wires to the appliance are not at 0 and 110 V (RMS) wrt to earth, but instead are each at 55 V RMS with opposite polarity wrt earth. I was using "+" and "-" as shortcut for that.

So for example there will be an instant when one wire is at + 77 V (55 sqrt(2)) and the other is at - 77 V wrt earth. Half a cycle later, the first will be -77 and the second will be +77. There will still be 144 V peak or

110 V RMS between the two wires, but only 55/77 wrt earth.

[Harry Bloomfield, Esq.]

Nick Odell presented the following explanation :

:-)

[Harry Bloomfield, Esq.]

NY has brought this to us :

Yes, you did - I missed it :-(

[Harry Bloomfield, Esq.]

They run their heavy appliances like ovens, on two phases I understand.

[NY]

I thought their "shitty two-pin sockets" were rated at more than 5 A. I know that high-power devices like tumble-driers and washing machines (on presumably electric fires) tend to be hard-wired in 220 V (like our cookers are) but portable devices like hair drivers and vacuum cleaners can be powered from a 2-pin power socket, so those sockets must be rated for more than 550 W (110 V, 5A).

Ah,

says that 2-pin NEMA (US) mains plugs are rated at 15 A.

Do modern US electrical standards mandate shrouded mains plug pins on new appliances, to prevent a child getting their fingers onto the pins while the plug is half in the socket and the pins are still connected? Or has that European rule not made it over to the US yet because the voltage is lower?

[Tim Streater]

Yes, my washer dryer was a 240V appliance. Fortunately there was a 240V socket in the garage which was there for the purpose.

[Tim Streater]

They may be rated at 15A but the fire danger is still real enough. Partly because the current is twice as high as we'd have it (so four times the heating effect in the plug/socket) but also because their plugs are unbelievably flimsy. Describing them as "shitty" is just me being polite.

[Andrew]

Indeed, and some of the ones I saw had been installed to suit the height of a typical South American, which is about 5 foot and a bit. I felt sorry for the lanky Nordic folk who had to use them.

[Andy Burns]

UK building site stuff is only 55V either side of earth, so even safer than USA 110V stuff.