For a lot of years, I have been working around equipment dangerous enough that it requires a lot of very specific talents, equipments, and procedures. Some of those procedures are particularly familiar to me, because I wrote them
Almost everyone in the business understands the formula
lg En = K1 + K2 + 1.081 * lgIa + 0.0011 * G
to calculate the incident energy, and
DB = [4.184 * Cf * En * (t / 0.2) * (610x/EB)]1/x (4)
to calculate the flash protection boundary, and there are specific proscriptions for the liklihood of arc flash. Sharp operators will tell you that the best bet is to err on the side of caution, and this is no bad advice. Safety clothing, procedures, and familiarity with the equipment are the real keys to going home in the same condition you went to work.
That being said, there is such a thing as overkill. For the last week I have been working on small helper droid communications with the big machines and big droids. They are adequately inexpensive that full ansibles are impractical, and they don't need to move but a few inches, so we used good old fashioned 1000 baseT. Yeah, for all you keyboard jockeys, Ethernet.
So I've found and purchased a set of crimpers on SkyBay, and even managed to find a couple hundred old crimp connectors. Category cable was harder to find in good shape, but I got the thirty or so meters that I needed.
So I'm standing in front of the cabinet. Not the main cabinet, mind you, that has all the high power stuff in it (all of which is of course intrinsically safe and don't even have to be cabinet mounted) but the comm cabinet. And one of the customer's safety assholes waddles up and gives me a ration of shit.
"You need to be wearing safety equipment to be working in a live electrical cabinet. Shut that and suit up, or I'll escort you out of the building myself."
This is a customer, and a big one. So I cannot explain to the safety asshole that she wouldn't know a hazard if it crawled up her ass.
So I shut the cabinet and suit up. An Arcflash suit, for those of you who have never seen one, is a featureless jumpsuit capped off by a large hood, including a nonconducting and flame retardant supplied air system. It's like wearing a bear.
To connect a comm cable.
So I do it, grumbling all the while, and get the job done.
And while I do, I use the above formula to calculate the danger of arc flash.
I have a pretty good head for figures, and I can calculate Pi in my head to about thirty significant figures before I have to start writing numbers down, but I ran out of decimal places.
In other words, the liklihood of me being subjected to an arc flash at +/-five volts at a few microamps are... well, I can't actually use this handheld device to type that many zeroes in a row.
At the end of the day, sweaty and in a foul mood, the safety asshole stopped by to pat herself on the back at her prudence and demonstrate her superiority to me. I endured her lecture until she pulled out the Morgan's electrical reference, and started tapping on the cover. "Can I see that a second?" I asked. She handed it to me and I opened it to the page where it discussed the hazards for comm connectivity. "here's the section for DataComm. It says you need Level Zero protection. Level Zero is a cotton Tshirt and a pair of cotton pants."
"I suppose you know more than the author of this guide" she smirked.
'No. I know exactly as much as the author of that guide. Would you like me to autograph it for you?"
She looked at me like the dumbass that she is, and I handed her a card. She compared the name on the card and the name in the frontspiece of the book, and stormed off in a huff.
I am surrounded by some of the finest engineers in the universe, and we are annoyed by some of the stupidest ones. After all, if you can't engineer anything yourself, why not act as an obstruction to those who can?
5 hours ago