TOOL MASTER
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- Apr 25, 2011
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high voltage danger
- Thread starter TOOL MASTER
- Start date
Ford12508
Well-known member
And boom goes the dynamite
BHR4CE1
Well-known member
Ah yes...I remember Sparky!
rabidsquirrel
Well-known member
We had to watch that in school as part of our 70E training. It sticks with you, especially when he starts burning.
OP
TOOL MASTER
Well-known member
- Joined
- Apr 25, 2011
- Messages
- 458
Just throw some bacon across 110 wires...
rockchucker
Well-known member
That was a harsh form of Electro-Shock Therapy.
I was doing some field work on the commissioning of a power system for a particular airport's new train system.
The particular system I was working on was the "shore power" for the cars sitting inside the garage. This powers the climate control, door systems, ect when the train is not feeding from the 3rd rails.
The voltage is 750V,DC, and there are two disconnects at the location: A manual lock out switch, and a contactor. The contactor is controlled by a train line connect circuit, it won't close until its plugged into the train and a circuit is completed.
So, in theory with the plug un-plugged there should never be any power, but the only isolation from the 750vdc is that contactor (and numerous procedural safety's).
The point to my story involves why I was there in the fist place. Apparently, one of the union sparky's decided he wanted to stick his fingers into the socket???? Of course in theory it should be open. But in reality because of a few details I can't get into there was actually a voltage there, and he got zapped! Luckily it was just bleed through with no current behind it so he didn't get hit with 750 (or he would be dead).
Why would a trained electrician, working on known high voltage extremely dangerous systems tempt fate like that?
Just goes to show, NEVER get to comfortable with electricity. Though I did fail my own rule when I was working on the system, I didn't verify power off with a multi meter after we went through all the disconnects. I didn't do this because someone else just had his hands on the dead bus, so I figured since he was still alive I was ok.
The particular system I was working on was the "shore power" for the cars sitting inside the garage. This powers the climate control, door systems, ect when the train is not feeding from the 3rd rails.
The voltage is 750V,DC, and there are two disconnects at the location: A manual lock out switch, and a contactor. The contactor is controlled by a train line connect circuit, it won't close until its plugged into the train and a circuit is completed.
So, in theory with the plug un-plugged there should never be any power, but the only isolation from the 750vdc is that contactor (and numerous procedural safety's).
The point to my story involves why I was there in the fist place. Apparently, one of the union sparky's decided he wanted to stick his fingers into the socket???? Of course in theory it should be open. But in reality because of a few details I can't get into there was actually a voltage there, and he got zapped! Luckily it was just bleed through with no current behind it so he didn't get hit with 750 (or he would be dead).
Why would a trained electrician, working on known high voltage extremely dangerous systems tempt fate like that?
Just goes to show, NEVER get to comfortable with electricity. Though I did fail my own rule when I was working on the system, I didn't verify power off with a multi meter after we went through all the disconnects. I didn't do this because someone else just had his hands on the dead bus, so I figured since he was still alive I was ok.
Displaced Hokie
Well-known member
Damn, that was some high voltage! What's odd is that it hit him twice. Almost looked like he grabbed it casually w/o knowing what would happen.
Damn that cooked him immediately.
Damn that cooked him immediately.
Ford12508
Well-known member
Great story from joe, but voltage doesn't kill
Great story from joe, but voltage doesn't kill
Yes, voltage alone does not kill. That is why the guy that got zapped didn't die, hardly any current could be drawn through the leakage path. Since the source at that point had very little current behind it, the voltage collapsed when shorted (through his body) to ground. Had the voltage maintained, it certainly would have killed him.
The voltage doesn't kill saying is very dangerous. In most cases that you encounter "high voltage" there is more than enough power behind it to kill you edit: turn you into a crispy critter no matter what your internal resistance. Since E/R = I, the bigger E (voltage) the bigger I (current) becomes unless limited by the source, aka. Tasers.
Joe
Last edited:
Bryanatkinson
Member
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- Jun 27, 2011
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- 9
I've also watch this vid in safety training too. Very scary indeed.
About hitting twice, the first strike might put him out of the contact temporarily
About hitting twice, the first strike might put him out of the contact temporarily