[RMVHF] Re: [GMCC] KC0TIG-Two Dead in Electrocution Accident

[Nate Duehr]

Phil Krichbaum wrote:
> Even 120 or 240 VAC is enough to end one's career!

DC across the upper body can be instantly deadly too, if done across the 
heart.

Getting hammered by a household 110VAC plug scares me a whole hell of a 
lot less than getting locked into the -48VDC plant at work -- DC caused 
muscle contractions that won't allow you to let go.

(Trust me, I don't like either one, but I'm ultra-focused around 
changing or installing high current DC.)

In the Central Officies (telco), -48VDC cabling is often far bigger than 
00 sized, where a tap off of that overhead feeder comes into a rack of 
equipment (usually more than one, dual-feed for redundancy) and then 
gets put into a remote power switching device that splits it out at the 
top of the rack, fuses/breakers for each piece of gear, and on down to 
the individual equipment.

Seen some guys do some accidental arc welding with -48 VDC cabling they 
thought wasn't hot before.  Those little voltage probes people like for 
AC safety don't work with DC, either.

So lock-out/tag-out procedures with a proper test when the circuit is 
shut off and again prior to working on it, is the only way to stay 
alive.  Not a bad idea when working at home either, really.

Nate WY0X