On 7/20/2014 7:50 AM, Larry Jaques wrote:
On 20 Jul 2014 00:52:54 GMT, "DoN. Nichols"
wrote:

On 2014-07-19, John G wrote:
wrote :
On Thursday, July 17, 2014 6:42:43 PM UTC-4, amdx wrote:
On 7/15/2014 1:20 PM, wrote:

Overhead commercial lighting voltage is 277 so its less current and less
dangerous, but what if a contractor is still more picky?

[ ... ]

it is false, that 277 Volts is safer than 120 Volts.

The 277 volt line may only deliver 1 amp to the light, it most certainly

could deliver several hundred amps for a short time and 20, 30 or even

50 amps continuously.

In any event, the power of commercial (even residential) wattage is
dangerous, but with more of it in voltage, its safer.

Please do not post rubbish.
There are some people trying to learn here.

The wattage used has no bearing on the risk of electrocution.
Any voltage above about 50 is considered dangerous and 240 is worse
than 120 and 270 ia worse.
The current will be dependant on the circuit resistance.

And, while the initial resistance will be a function mostly of
the moisture and salinity of the hands contacting the voltage source,
once the initial current starts to flow, the skin breaks down and the
resistance drops rapidly -- and the more the voltage, the more rapidly
the resistance drops. And the current needed for a fatal dosage is well
below the trip current levels of commercial circuit breakers. (I do
have some glass cartridge fuses rated at 1/100 Amp (10 mA) which should
be enough to protect you -- but not enough to allow most equipment to
operate, so that is why I still have those fuses unused. :-)

Anecdotally, 240 is safer because it will kick you off more quickly
than 120v. If you fall into wires and complete the circuit, you'll be
dead more quickly, but brushes against it are, IMHO, safer, and I'd
rather work with 240 than 120 for that reason. 5mil nitrile gloves are
a part of my DVM package, and I wear them when working with live
circuits. You can feel the voltage start to bite through them and
move your mostly-water body parts quickly out of contact. When
convenient (maybe 1/4 to 1/3 of the time), I shut off the breaker.
I have a healthy respect for deadly but wonderful electricity.

CAVEAT: Kids, don't try this at home.

--
Liberalism is the result of severe pathogens in our society.

I had a friend years ago who's dad was a licensed electrician. Actually
2. Taught Electronics and dads push the 'new' stuff on the kids.

Anyway he was working in the Engineering building and with the cover off
a 880v 3 phase box - he was working the box hot. Normal. Power down
all sorts of expensive machines on those lines... He dropped his
screwdriver down into the panel. Vaporized the steel, plated his face
and upper body - his glasses in side of his goggles saved his eyes.
He was in tough shape for a month or so at the hospital.

One has to be careful. Now they sell Be metal drivers and coated drivers.

Martin