Industrial Electrical Question

[HEMI®Dart]

These switches are in an electrical room at work. Not sure if they're in service or not. What do the warnings mean? Can't turn switch?

 

[HEMI®Dart]

Also, We have to "Rack out" our 4160 Volt panels once in a while. It's a different procedure than in this video. Something goes dreadfully wrong in the video below. Watch at 1. 15 mark.



2:00 arc flash interior substation racking breaker refineria Barranca Ecopetrol - YouTube

 

[Dl5treez]

Looks like fun... in a way.

 

[GHarman]

While I am not an electrician, I have done extensive work with/applying "Lock-Out, Tag-out" procedures, to electrical systems and pressure piping . That switch appears to be in use. A trained electrician must be involved, otherwise stay away. "No!" is not a bad word! If you are told, "it is turned off" and it is not marked with a tag and locked with a key lock! Treat it as if it is LIVE! That is a safety issue and should be corrected, straight away!

If it is powering operating equipment, stay away from it!

I have seen 480V 3 Phase fuse boxes blow with a 3' blue flame! I would not want to be standing in front of one!

GregH

 

[fest3er]

The warnings mean

• Disconnect the upstream power source before removing the panel's cover. Period.
• Do not ever work inside the panel when its power source is live.
• (I think) a flashover can be triggered at less than 18", and the flash can extend to 220".
• You must wear class '00' gloves when working on the panel.
• The approach limits govern how close something or someone can get under specific circumstances.

Or, as Bugs' arch-enemy might say, "Turn off the power, and be vewy, vewy caweful. "

 

[HEMI®Dart]

The warnings mean

• Disconnect the upstream power source before removing the panel's cover. Period.
  
• Do not ever work inside the panel when its power source is live.
  
• (I think) a flashover can be triggered at less than 18", and the flash can extend to 220".
  
• You must wear class '00' gloves when working on the panel.
  
• The approach limits govern how close something or someone can get under specific circumstances.
  

Or, as Bugs' arch-enemy might say, "Turn off the power, and be vewy, vewy caweful. "

Thank You fester!

 

[rbattelle]

I have to wonder, is that sticker placed on the wrong box? I wouldn't expect a 480v line to be able to arc 18", and certainly not 220". Maybe that sticker is supposed to be on a 4160v panel?

What do I know, I'm not an electrician. I've simply never seen 480v equipment with such extreme precautions.

-Ryan

 

[TRAMPLINEMAN]

I've worked on live 500KV and that didn't arc til about 6". 480V, in my opinion, would never arc at 18".

 

[Dl5treez]

The "warning labels" change it seems like each code cycle. Those may or may not be older placards to requirements that have been updated since by the NEC, NFPA, etc.

A 480VAC panel can produce a large arc flash... . 220 inches, ~18. 5 feet, isn't all that far away when you think about it. The light is bright enough to blind you--think welding arc times about a billion.

 

[Dl5treez]

I've worked on live 500KV and that didn't arc til about 6". 480V, in my opinion, would never arc at 18".

Were you barehanding in a Category A aerial, or otherwise insulated from the source and ground?

 

[TRAMPLINEMAN]

I've barehanded out of an insulated bucket and from an insulated crane basket. I've also barehanded off of fiberglass ladders hanging from structures.

 

[The patriot]

My first job out of school I was about a foot away from some guy who crossed a screwdriver on a 440 panel. He lived.

That pretty much did it for me and electric.





I used to have to mess with stuff like that.

I was the Sr. plant engineer... . when the maint guy was "busy" (having a smoke or sleeping somewhere)I'd get stuck with it.

I dont miss that stuff at all. #@$%!



The company sent me to a electrician safety school. I guess they'd think it would turn me into a licensed electrician or something.

When I got back they asked me "well, what did you learn?"

I told them "the school said I should be getting an electrician to do it. ":-laf

 

[HEMI®Dart]

I've barehanded out of an insulated bucket and from an insulated crane basket. I've also barehanded off of fiberglass ladders hanging from structures.

Were you nervous doing this?

 

[fest3er]

As long as I'm not grounded (am insulated from earth), I'm not at all nervous handling live wires. Of course, I've never seen more than 120VAC, and I don't know the maximum voltage one can barehand when adequately insulated from earth; it's probably higher than I think.

 

[Dl5treez]

As long as I'm not grounded (am insulated from earth), I'm not at all nervous handling live wires. Of course, I've never seen more than 120VAC, and I don't know the maximum voltage one can barehand when adequately insulated from earth; it's probably higher than I think.

Have witnessed it with 500KV, and I believe it is possible even higher, and with DC transmission lines.

 

[TRAMPLINEMAN]

Were you nervous doing this?

No. I have pics of me with energized 500KV in my mouth.

 

[HEMI®Dart]

I've barehanded out of an insulated bucket and from an insulated crane basket. I've also barehanded off of fiberglass ladders hanging from structures.

Was this something like you do?



High power line workers (V. 2 Better Quality) - YouTube

 

[TRAMPLINEMAN]

Was this something like you do?



High power line workers (V. 2 Better Quality) - YouTube

Yes. Either off a chopper, insulated ladder or insulated bucket/basket. They also make a little cart that hangs on the wire by riding on wheels, called a spacer buggy. A guy would ride in the buggy along the wire and either install, remove or replace spacers as needed. You normally would have on guy on each phase and it's always a race!

 

[HEMI®Dart]

Yes. Either off a chopper, insulated ladder or insulated bucket/basket. They also make a little cart that hangs on the wire by riding on wheels, called a spacer buggy. A guy would ride in the buggy along the wire and either install, remove or replace spacers as needed. You normally would have on guy on each phase and it's always a race!

OMG TRAMPOLINMAN! I don't know how you do it!

 

[Mikey-KE7LBB]

Simply NUTS!!! IMHO, BUT the warnings on every panel in an electrical room where 480V the ONLY thing that is 'common' is just plain annoying and may lead to complacency and 'pencil whipping' on a stupid JSA when it could cost your life!!!



Competency & training are far more important to me than whichever 'idiot' than can make it sound the best on paper!!!



Electricity kills!!! That is a FACT!!! Can't see or smell it, but a "sticker" isn't gonna save anyone's ***** that has a clue how it works!!