Getting shocked with engine running

[SloopJonB]

Originally Posted by mitiempo

That is not 12 volts.

If I understand Ohms law, to get the high voltage to arc, the amps or watts would have to be cut back drastically. If the amps were cut back that high voltage would be akin to static electricity - a Van Der Graaf generator has about 40K volts, so it must be the wattage that suffers. No?

That would indicate that Boatpoker is correct - the amperage is the problem.

Of course I get a man in most times when I need electrical work done.

[mitiempo]

That's right. An ignition coil produces 20,000 or more volts but at low amperage. The voltage has to be high for the spark to jump across the gap of the spark plug. It is less dangerous than 110 volts from an outlet in your house. But it can be felt. Anyone who worked on cars (when they were easy to work on) has probably had a buzz from a coil. I don't know if it can kill, never held onto one long enough to find out.

Does the original poster have a gas engine?

[mitiempo]

I found this interesting article concerning the voltage/current needed to injure or kill. As it states, it is the current that kills but voltage is needed normally to overcome the resistance of the skin. There are factors that can change this - contacting a ring on your finger for example. Generally 30 volts is the threshold of danger which pretty much leaves 12 volts in the safe range.
Ohm's Law (again!) : ELECTRICAL SAFETY
Well worth reading.

[Augsbut]

Thanks for all the ideas. I'll report more after investigating this afternoon. FYI, diesel, no inverter......

[emoney]

300-500 mA of DC current can cause fibrillation which leads to cardiac arrest.

It's the amperage that's providing the shock...i.e how much current is flowing, not necessarily the source of the current.

I've seen guys get severely shocked working on guitar tube amps that had zero current running to them at the time. However, the amperage was already built up inside.

[davidpm]

Originally Posted by Augsbut

I was away from the dock but didn't have time to trace. I'll go out tomorrow and see what I can find

do you have an inverter on board making 110volts?

[AdamLein]

Originally Posted by emoney:798520

300-500 mA of DC current can cause fibrillation which leads to cardiac arrest.

It's the amperage that's providing the shock...i.e how much current is flowing, not necessarily the source of the current.

We've been over this. Yes, amperage is the danger. But skin has high resistance that the current has to get past to cause damage. High resistance makes for low current.

[boatpoker]

Originally Posted by AdamLein

We've been over this. Yes, amperage is the danger. But skin has high resistance that the current has to get past to cause damage. High resistance makes for low current.

Wet hands .... wet feet .... lower resistance.... Water ? surely not around a boat !

[emoney]

Originally Posted by AdamLein

We've been over this. Yes, amperage is the danger. But skin has high resistance that the current has to get past to cause damage. High resistance makes for low current.

Tell that to guy getting shocked....

[dabnis]

Originally Posted by emoney

Tell that to guy getting shocked....

Right, many, many years ago I was a telephone installer/ repairman. Ringing current was 20 cycle 80 volts AC, not sure how much amperage, but probably not much. That being said, when standing on wet concrete and getting zapped with it my involuntary reflex resulted in throwing my lug wrench about 30 feet away. "Talking" current was 48 volt DC with minimal amperage, when I wet my fingers I could feel a slight tingle from one finger to the next, a lazy way to see if the pair was "hot". I hate getting shocks, especially from leaky
ignition wires while working in close quarters while an engine is running. I guess everybody has their own tolerances, mine just happens to be very low.

Dabnis