ECN Forum Forums Safety Discussion and News Occupational Safety Discussion Two Person Rule When Working on Energized Systems

Yes, and make sure it is of the type that can be used on an electrical fire.

I can't do any research as to the type now because I am in the back of a shuttle van going to the Denver Airport.

Joe,
Let me say this,
There is only one type of Fire Extinguisher that should be used on Electrical Fires.
And that is Carbon Dioxide (CO2), it has superior "Knockdown" characteristics, is non-corrosive to Electrical Equipment and it freely disperses after discharge.
It has the dual effect of both cooling and starving the fire of Oxygen.

Joe,
Sorry I'm late on this one, ThinkGood seems to have covered the 1910 ref. for Medium Voltage, you can also find references in the NESC.

The reason you'd have difficulty for under 600V is.... It's NOT allowed. You can search 1926 all you want you'll only find reference to Lockout/Tagout. They make no provisions for working energized equipment.

The concession to MV circuits was made long ago, because 1) the Utility workers are more trained in the aspect and 2) Because they are able to work energized the resulting inconvenience to customers was weighed in as part of the equation.

It also goes a bit deeper than inconvenience. When you interrupt an MV distribution circuit, you may have to reenergize by opening up lots of stuff downstream or risk system failure from overload.....

The very reason on Thursday they could not wait for the system to "Calm down" and simply reclose all breakers, the resulting inrush/locked-rotor would have devastated the system. Trumpy had the term perfect "Hunting". Yes, it is scientifically Sub-synchronous resonance, but since the gen actually "hunts" for the right spot, it is a better term.

Anyone with REALLY old CEE's would find an article on a genset of mine that did just that, at which point I dove in and opened it (it makes a BEG difference if you are the one who would have to repair the gen )

Since anything under 600V is local by nature, OSHA saw no reason to have rules for working energized. Again, it also had to do with how highly trained ALL folks in that field are on the subject. This group here is pretty danged sharp, but there are lots out there that would get hurt.

Now, anyone here ever work it hot????????
Course, not!!!!

George,
Yes, I hear what you are saying about Live work under 600V.
You and I both know, through HV work that the animal of Live work at any voltage is dangerous and should be avoided at any cost.
George, this is a situation that I deal with on a daily basis, just having the maps of all the Distribution Systems where I am working and Direct communications with the "Control Centre"(Gives Line Clearances and advises on switching sequences), makes things for me, a helluva lot safer.
One thing that I would personally agree with you is, the fact of TRAINING, nothing can train you better than 4-5 years of working every day with high voltages and I would hate to see a rash of Electrician's rushing out to "have a go" at Live connection work, after all, your eyes don't tend to work too well after having an Inch of molten copper thrown into them!.