04-21-2012, 01:21 PM
Well, I designed power supplies for India, of all places. Just a year ago. For customer premisses (a house or an apartment). Their requirement was for it to work up to 270V AC - their lines are so bad the voltage goes all over the place; 160V-270V is working voltage for 220V nominal.
I spend the beginning of my career back in the USSR, and I saw firsthand how a metal-boxed display station was grounded to a 220V hot wire (a person who wired the place was drunk and switch the Hot and Gnd places). That was not all of it - the shield GND was connected to the Neutral using a neutral as GND. So the display actually worked, but then couple of folks, software guys (I was a hardware Eng there) came to me, complaining to being "bitten" from touching the case (luckily the floors were not GND, otherwise they would not come to me....they'd come straight to the mortician). I went, investigated, found that, raised H**l; the work was stopped and the place was properly re-wired. (The wiring person was not fired.....was not even reprimanded).
So, yes, I am aware of how things work in there.
Better yet, when I was in a reservist camp, receiving my leutenant's rank (so I was essentially a cadet, a private, after a university), I was asked to look at a piece of kitchen equipment, a potato peeler, which was peeling potatoes (usually they used privates for that, but this location was mechanized beyond belief....a potato peeler, that was almost like from fairy tales
) for the whole contingent.
I went in. It was a basement, and it was flooded, so I walked in water up to my ankles. The peeler was not grounded, and was connected to 380V (3 phases). I did not even have a meter. So what I did - I, at my own risk, running my hand full speed past the peeler, briefly touched the case. Got a huge jolt, but due to very fast speed of my hand it lasted, probably, a millisecond.
Then I went to my commanding officer and told them that they are about to have people killed, and they should stop using it.
Whether they did or not - I don't know. This was last time I looked at it.
I spend the beginning of my career back in the USSR, and I saw firsthand how a metal-boxed display station was grounded to a 220V hot wire (a person who wired the place was drunk and switch the Hot and Gnd places). That was not all of it - the shield GND was connected to the Neutral using a neutral as GND. So the display actually worked, but then couple of folks, software guys (I was a hardware Eng there) came to me, complaining to being "bitten" from touching the case (luckily the floors were not GND, otherwise they would not come to me....they'd come straight to the mortician). I went, investigated, found that, raised H**l; the work was stopped and the place was properly re-wired. (The wiring person was not fired.....was not even reprimanded).
So, yes, I am aware of how things work in there.
Better yet, when I was in a reservist camp, receiving my leutenant's rank (so I was essentially a cadet, a private, after a university), I was asked to look at a piece of kitchen equipment, a potato peeler, which was peeling potatoes (usually they used privates for that, but this location was mechanized beyond belief....a potato peeler, that was almost like from fairy tales
) for the whole contingent.I went in. It was a basement, and it was flooded, so I walked in water up to my ankles. The peeler was not grounded, and was connected to 380V (3 phases). I did not even have a meter. So what I did - I, at my own risk, running my hand full speed past the peeler, briefly touched the case. Got a huge jolt, but due to very fast speed of my hand it lasted, probably, a millisecond.
Then I went to my commanding officer and told them that they are about to have people killed, and they should stop using it.
Whether they did or not - I don't know.
This was last time I looked at it.
