No comments on the various formulations & guides - some old tech
is still valid
, just a cautionary observation/experience.
When I worked at Hughes Aircraft in Tucson, AZ (USA), we had a lot of DC-powered test stations. One night a tech was called in to work on a test station. Unfortunately, his testing had to be done on a hot
, with the power on. (It didn't have
to be done hot, but the difference was several hours as opposed to a few minutes.) He got across 400 volts DC. It literally threw him halfway across the room - perhaps I should say his muscle spasm when he got across the contacts threw him halfway across the room. I helped to recover him, get him on a gurney the shop nurse brought. Significant, if not major, burns on this hands and arms, and a partially dislocated shoulder from jumping away while trying to hold on.
Up until that time, in my ignorance and supposed invulnerability, I was wont to work on 120V AC circuits hot - home wiring and the lot - comfortable in my presumed immunity. I don't do that any more. (I've also gotten burned fingers working with 9V lantern batteries, but that's a different matter.)
Anytime you're working with current, you can be in harm's way, even though the amount of current seems minuscule.