Re: NFPA 70E
I think I am qualified to say some things here.
1. Have MS in safety and industrial hygiene and more important 20 yrs of FIELD (NOT DESK) experience.
2. Did Master thesis on UV and blue light emitted by weld arcs. Close subject to electric arc flash and NFPA 70. Granted power levels 1/100 or 1/000 of that in switchgear (or even some house panels)
3. Learned power generation and distribution on US Navy submarine.
4. I know 3 guys who have done arc flash - 3rd degree burns and all that.
5. Worked at Trojan we had it all up to 230KV.
Hot stiks the whole deal.
6. Tore down and rebuilt several switchgear that had blown out and melt down.
OSHA does come out with these requirements often they are not well thought out - I hav always wanted them to test (real world in the mud not a lab) before requiring. They require MSDS - most are not worth the paper printed on
-- "use gloves" uhh which ones
-- "well ventilatd area" what does that mean?
This evaluate the hazard stuff
- what do you use for the trip level
- instant short delay long delay and associated times??.
Can of worms you can pick worst case say instant and multiply by the long term trip time
AT THE COST
of having your guys triple bundled and almost able to do nothing because of loss of dexterity.
As far as shutting down power lets look at somethng simple replace 277 V lite ballast. If you kill the power the whole office goes dark. No one can work
- simple do it on back shift
WHUPS gotta pay shift premium or overtime.
we gotta have someone with key to get in
Ahhh the hell with it do it hot.
Uhhh use hot gloves - on # 18 (or 20??) wire for the ballasts and then the little orange and blue wire nuts? Not easy I know.
On submarine we could easily shut down half the plant and bring it back up easily. That was in 73 things were simpler then. BUT you still had power in the main control panel for the generators and breakers. Since we were Nuc you could NOT shut it all down SO when changing or doing a meter cal you were working hot even though it was only instument / control (480V on a 2 A fuse)
Safety is good, I am no longer in the field because of all the useless BS and frustratiion (mostly from my own direct management).
IF I put my mind to it I can shut down darn near any operation with safety requirements.
The bottom line in my mind is this
HOW to get the job done in cost effective manner
AND EVERYONE GO HOME OK.
I am not sure of the answers but I think I have a pretty good idea what the questions are.
Hmmm maybe there is a business opportunity here.
Dan Bentler
