I was working on a live 150kw generator looking for a high resistance short without a megger.Dumb mistake to say the least.I saw 3-4" long blue sparks fly out of my elbow.
I had my arm near an air grate with expanded metal.The shape of the metal was burned into my elbow.I could not do a pushup for three months after because that elbow was to burned inside at the joint.
It hurt like heck but I did fix the generator.
I learned respect for electricity in a big hurry that day.
Take your time & do it right!
Been bit with 277 a few times, never like it. 120 more than I can count. As an electrician by trade the biggest killer I have seen is metal to metal shorts, not skin contact. Not saying contact can’t kill, but when the metal shorts on a juicy circuit it vaporizes and explodes. If the molten metal doesn’t kill you by inhalation the explosion will. A cheap tick tester is your friend. Rings, watches, necklace, etc best be left home when working with electricity.
Last dude I saw on the job that had a serious injury dropped a 4 square box cover into a piece of switchgear. The blast granted him third degree burns over most of his upper body. Pay it respect or you’re a dead man.
I have never been hit by 480, but I have been working around it for several (8?)years and do worry about it. I do not trust disconnects, I have seen a few bad ones, I visually verify them. I have some disconnects that cannot be verified visually (liebert). I do not trust my meter either(they can fail too), I will take a nut-driver or two if needed and 'ground' the 3 supply wires to be sure.
If I ever screw-up, I expect it will be in a situation where I am turning the power on an off alot of times and 'forget' status of power. Of course, we work on stuff with the power 'on' all of the time, so it can get you anyway if your number comes up. Disconnect off, check, then there is lightning,...
I have taken a rather morbid 20 year poll of co-workers who were hurt in accidents. The one common thread was 'I was in a hurry". I hope this helps.
"You boys are really making this thing harder than it has to be". Me
"I say we just nuke them from space, that is the only way to be sure". Winch from ALIENS, forgot her name.
Service calls submitted after 3PM will be posted the next business day.
I give free estimates [Wild Ass Guesses] over the phone.
My front door is locked. For your personal protection.
i was gonna work onna motor in a cooling tower pond once ...
I pulled the MCC disconnect lever....
went to the "pond" ...
didn't feel safe, standing in water, so tested ..
MCC disconnect lever came down, but didn't retract the stab's .....
Very true, slim. That is why I ALWAYS check voltage to ground and phase to phase after I have "opened" the disconnect. Knife switches can fail just like anything else.
"Nearly all men can stand adversity, but if you want to test a man's character, give him power."
The only way to be safe:
1: Lockout and Tag
10 replies until this..........I'm surprised actually.
Originally Posted by Wj Stevens
Cheap, impressive, and can save your life
Quite a while ago I was working in a mechanical room checking voltage to find out why a 20 horse body wouldn't lite up. This was 7:00P or later on a Saturday..........probably had 13 hours in by then......In a hurry - had more calls to take.
While checking the contactor coil voltage I accidentally touched my meter lead from L1 of 480 to one side of a 115V contactor coil.
I remember the flash and being thrown across the room. The line short took out the back room overhead lights and the cash registers in the store. Not to mention the main for the rack.
The flash must have burnt my eyes, because I had a painful sensativity to light for almost a week.
Took me quite some time to check control voltage again without physically shaking.
i have one of them but with 460v i still use my vom to verify
Originally Posted by zzonko
I dont warranty Tinkeritus
my story, last year i had a weekend service call, customer had no ac. so i got there and relised the until was out of freon and the compressor was off on internal overload. i figured it was pretty warm outside, so id do them a favor and charge it and come back the next business day and leak search <weekend rates are super steep> well, i figured being i was in a rush to get home to have dinner with the family id dump water on the compressor to cool it off. so i remove the disconnect and start dumping water via water hose into the top of the condensor. a bit later i figured id start the unit. there was a thorn bush behind the unit so you couldnt get to the service panel. so i plugged in the disconnect, fan took off but no compressor, i was very supecious then. so i layed across the top of the unit to pull the service door off to have a peak. pulled the door down and life began in slow-motion for me. the 7.5mf 440 vac capacitor fell out and nailed me on the finger. i felt it up one arm through my chest down the other arm and it pulled me to the until, luckly the staycon on the capacitor came off,<shortly after it cooked into my skin>. a year later im still missing a chunk of skin on my finger. the problem? unit out of r22, fan motor wired on line side of contactor, capacitor wasnt strapped in the unit not had a cap on it. just setting in there all by its self.
The only way to be safe:
1: Lockout and Tag
A while back I was told to buy one of those voltage testers you can carry in your shirt pocket and I never got it.... Im getting one right now. Im also getting all those lock out tags.
Before I had left the job to get those parts I remember that i had turned of the air handler switch and i had turned off the circuit breaker, now before diagnosing the motor I remember that i turned the switch back on and checked for voltage. I had found that the circuit breakers had not been labeled properly and so i just wanted to be safe. After I checked for voltage i went straight to diagnosing the motor instead of turning that disconnect off, that was my bad too.
My boss told me that i am still alive because im big, does being overweight help you in any way, probably a stupid question but oh well?
This Absolutely scared the Fack outta me ......
Originally Posted by whec720
I check ... Everything ..now ...
Dam .. I'da been .... smoked ....Toasted ... DEAD ...
I live by lockout/tagout rules. I enjoy going home after work too much to take chances.
One time, years ago when I was doing residential, I was working on an oil burner in a trailer. THe furnace had a safety switch on the door, the kind that works like a normal switch with the door closed or you can pull the switch out and lock the unit on to service.
Well, I was "in a hurry" and needed to check the ignition transformer. So I flipped it open off the burner, grabbed a screwdriver and laid it across the transformer, reached up to the switch.
Thank God I pushed in on the switch and didnt pull it out to lock it. Here, I had picked up the customer's screwdriver which the shaft went clear through the handle and was mushroomed on the end of the handle The screwdriver was in my right hand and sparks came out of my finger on my left hand when I pressed the button. Knocked me backwords which shut off the furnace.
My helper laughed so hard that I thought he was going to pee his pants. No permanant damage but boy did my chest hurt the rest of the day!!
Character is like a tree and reputation like its shadow. The shadow is what we think of it; the tree is the real thing.