I was always told
Its Volts what jolts and Mills what kills.
Being a solid state inverter, the case of the inverter may be earthed on the DC input side, the AC mains output side may not be earthed to the case - ie may not share the same earth. The only sure way is to take an earth lead from the three pin mains plug earth in and spike that in the ground.
For sure your source of mains (ie the car) will not be earthed to the ground -
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Alternitively use an IP65 rated inspection lamp, and wire this to a length of 3 core flex in the same way you would connect it to the lighting circuit in a house. Stick the plug on the other end.
IP65 will cope with most outside conditions short of total immersion in water. An anti vandle bulkhead will suffice. I would consider mounting this on a piece of 20mm ply, making sure the mounting screws don't penetrate to the other side, and use it in the 'flat' postition outside.
Also, take careful note of the instructions. There are things you have to do to maintain the IP rating, like making sure the cable access is watertight, and make sure the holes for the screws are sealed with silicone sealent.
Also, make sure the mounting screws do not come into electrical contact with any of the live, neutral or earth. Alternitively think about using plasitc nuts and bolts to secure it.
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I have a little experience in this, enough to know not to try to be clever with electrical devices, especially mains voltage ones. Why do you need mains voltage at a camp anyhow? You can get everything you need for a campsite with 12 Volt supply. I have had a 12 volt inspection lamp longer than I have had a 240 volt one. I bought it in Durban RSA in 1968, it has a magnetic base to attach it to the underside of the bonnet.
Separately, 24 Volts has been known to kill.
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"Separately, 24 Volts has been known to kill."
As RF says, it's not the volts that kills it's the mills.
24v can kill if there is enough current going through you, think of it as water flow. The Voltage is the height between the ground you are standing on and the bottom of a huge water tower. The current is the rate of flow. A drip at several hundred feet up could be annoying, whereas the bottom falling out at 15 feet would probably knock you off your feet.
I have put 500v through me and I am still here. No, I am not a superhero (couldn't get the Y fronts in my colour) it was my mains insulation tester. The current was minimal so I just felt a sensation in my fingers.
Another factor is the time your body spends exposed to the voltage.....
For domestic installations the IEE use a 50V "rule". That is to say that a maximum of 50V for max suration of 0.4 seconds is "acceptable" to the body. In some circumstances this can be justified up to 5 seconds (plug in equipment etc). This is of course for normal installations.
I'll stop here before I have to moderate myself and put this in I have a question....
Before I go, taking on board what hillman wrote, why not pop into a car accessory shop and pick up one of those multi function light (torch, flasher and flourescent beam) that works off either 9v or 12v cigar lighter?
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If you must use one of these, my instructions above have a lot of merrit. There is need for use of an RCD but also great care in the way such a converter is connected. An RCD will not save you if you do not connect properly before its use.
RF says The only sure way is to take an earth lead from the three pin mains plug earth and spike that in the ground.
Not a bad idea. Even better if one of the two live wires is connected to the case. But is it?
We might have a converter with a pair of output wires that are a floating supply -- depending on its design. Neither wire is then earthed.
Now consider using such a converter with an RCD plugged in. But also that one piece of your equipment has contact with the ground and it happens to be faulty such that one of its two wires is leaking/connected to the case, due to dampness or whatever -- it does happen. So now we have one of the two wires from the converter that is being earthed. But the DC converter will continue to work.
Now suppose someone is standing on damp ground and makes use of another piece of equipment, possibly a metal cased lamp, and that the metal case of that happens to get into contact with the other wire, just as it is being handled --- it does happen.
That person now gets a potentially lethal shock! But worse, the RCD does NOT trip because the current flows equally through both wires. (draw the circuit out and see)
However, had it been wired as I suggested above, where one of the two wires was grounded BEFORE use of the RCD, it would have tripped!
Ideally test your system with a dummy load before use to make sure you have it right.
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Meh, if we're getting into the subject of voltages, I've had 2 million volts and a fairly sizable current put across me at Uni...
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Use a 12v 13w compact fluorescent lamp instead of a 240v lamp.
A 13w will give you approx 600lumens, similar to your average 60w incandescent bulb.
No casing or IP protection required, will have a life of 10000 hours plus, and will cost you around £9.
And it's completely electrically safe.
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Agree with Hawesy, although fluorescents do show false colours sometimes - not a big problem unless you're rewiring the car...
I used to have a cheap 12V inspection lamp that used ordinary 21W brake lamp bulbs. It was very effective despite the relatively low wattage.
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I've just toured France with a 'petit tente' for a few weeks.
Charged mobile phone and battery powered spotlight from the car sockets. Probably can get a similar charger for your video cameras.
Got too complacent after 2 weeks and left courtesy lights, 12V spotlight plus mobile 12V fridge running long enough to flatten battery on my Passat diesel.
Well, the rose wine needed chilling.
Campsite proprietor competently jump started my car with no problems.
Just needed to reset the clock and the fuel computer thingy had lost its memory.
--
I wasna fu but just had plenty.
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Stick with 12 Volts or use inside the car only.
IIRC RCDs work on mains because the earth is the return path to the power station, The electricity distribution grid is three wire distribution with neutral being the imaginary centre of the three phases. There is only a neutral where it is 240v single phase.
Your car is not earthed so the return current will not seek to return via the earth unless you connect the invertor neutral or car neutral to earth - as you would when getting into the car! Overload protection (std circuit breaker or fuse) will work but RCDs may not.
Having seen holes burnt through PCBs due to high induced earth voltages I would be very wary of earthing outside buildings.
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IIRC RCDs work on mains because the earth is the return path to the power station
Exactly. One of the two wires to your house is earthed BEFORE it gets to the RCD at the house. Just what I was advocating above, that should be done with one of the inverter outputs. In effect, make the inverter your new 'power station'.
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IMHO the earth connection is not essential. It's the current going to earth (e.g. through you and/or when there's a fault) that creates an imbalance between live and neutral and trips the device.
In household mains, the neutral line is so called because it is at earth potential (0V) and the live alternates from +240V to -240V, which may not be the case with an inverter.
However, as the name implies, residual current detectors (RCD's) are current driven, and all they do is compare what goes up one wire with what comes back down the other, and trip out if they're not the same!
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"24v can kill if there is enough current going through you"
Listen to Hugo. The current that flows through you depends on volts, certainly, but it depends more on the resistance of your skin. If your hands and feet are wet and muddy (as at a camp-site) it's a completely different situation and 24V has killed. The effect also depends on your state of health. What a young fit person can shrug off might stop an older person?s heart beating. The effect of an A.C shock from an inverter is different from D.C., from the car. A.C. will make your muscles go into spasm, and you will clutch the source. D.C. is much less onerous.
Don't compare it to a Megger insulation tester. That is the trick that you play on apprentice electricians. If you hold onto the wires tightly then you will be OK - although the voltage is 500V the current is very low. If you let go it will kick you. Likewise, one of the tricks played by old time mechanics would be to hold a finger on a spark plug and touch the arm of the apprentice. That was when the plugs fired at about 12 000 volts. Don't try it now, the voltage is much higher. Both cases were lots of voltage and very little current.
I can only repeat, Don't mess around with mains voltage devices, especially if you have a perfectly suitable 12V ones.
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"A.C. will make your muscles go into spasm, and you will clutch the source. D.C. is much less onerous."
Other way round. One reason why DC mains didn't catch on, as if you got a shock, you couldn't let go!
Agree with everything else, though. 240V next to your ear while you're on your back in a muddy campsite is not a good idea!
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Bonnington I remember Nottingham being changed over from DC to AC. A friends Dad knowing this was to happen bought up some surplus DC machine tools from Raleigh Cycle factory.
When the changeover came the Electricity Boad replaced them all with new. This would have been in the 50s. I wonder who was the last City to change over.
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Hillman..your mention of the megger brings back memories of fifty years ago when they had handles on the side to wind up.
It used to be a competition on site who could hold on the longest. Didnt realise the one who used to win held it the tightest.
I was always impressed by the cable jointers who made new connections of one of the phases to supply a new building.
Working at the bottom of a muddy trench standing on a rubber mat with the supply on, stripping the insulation and making lead wiped soldered joints off them. Death wish crew we used to call them.
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When I had a part time job welding trailers it used to be a competition to see who could hold on to a live welding rod and the chassis the longest....
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IIRC RCDs work on mains because the earth is the return path to the power station Exactly. One of the two wires to your house is earthed BEFORE it gets to the RCD at the house. Just what I was advocating above, that should be done with one of the inverter outputs. In effect, make the inverter your new 'power station'.
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I understand that the equivalent of the neutral wire is earthed at the source.
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