Needs Pictures Needs Pictures:  0
Picture(s) thanks Picture(s) thanks:  0
Results 1 to 10 of 10
  1. #1
    Join Date
    Sep 2010
    Location
    Lebrina
    Posts
    1,910

    Default Electrical safety for welders

    I would like to share a recent personal experience of mine.
    I am/was a regular fortnightly plasma donor up until Boxing day 2015 when I was knocked back for having an irregular heart beat.
    I was informed that it was probably nothing to worry about and even an oncoming cold could bring such an event on. I felt fine (until I came down with the mother of all flu's/colds). I would need a doctor's clearance to resume donations.
    I was busy and I admit tee'd off over what I saw as a gross over reaction. I thought "stuff them, I'm not making an appointment at my expense to sort out their issue." Silly I admit.
    Move forward 18 months and I tore a tendon in my shoulder. Hey Doc, while I'm here, can you clear me and fill out this form? Out came the stethoscope and sphygmomanometer. No can do son, I want to know more.
    Long story short, I was diagnosed with Atrial Fibrilation, thankfully now sorted after the application of a few Joules of elictrickery.
    Given that this condition manifested within a fortnight period, I racked my brain as to what had occurred in that period. I do believe that I copped a 340VDC boot off a plasma cutter during that period. I asked the medical staff and they agreed that the shock could have been what set off the condition.
    Moral of the story. Avoid electric shock, if you do get one of any magnitude, get checked out and finally, don't ignore a warning because you are busy.
    I was lucky.

  2. #2
    BobL is offline Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    7,182

    Default

    You were lucky with that 340V DC hit, it must have been low Amps because otherwise you would have sustained an serious burn.

    Most people don't realise they should get checked out if they get a boot - the older and younger the person involved the lower the V needed to affect them.
    DC is worse in some ways than AC so lower V for a DC boot before you should get checked out.

    I was at a barista completion a few years ago when one of the 3 phase coffee machines would not start. They asked me to look at it and I said "call a sparky as I'm not qualified". Some onlooker said he would look at it and got a decent boot that knocked him over. He went very pale and shakey I said he should go to the hospital which was just down the road and a couple of us offered to take him but he would not go. I was going to call the hospital but after about 5 minutes he disappeared.

  3. #3
    Join Date
    Nov 2008
    Location
    North Brisbane. Qld. Australia
    Age
    70
    Posts
    1,511

    Default

    Quote Originally Posted by BobL View Post
    Most people don't realise they should get checked out if they get a boot -
    I did not know this. It was at least ten years ago now I got an almighty boot from a 240V supply, when a switch I was removing from a wall, had a loose active wire which cam out and touched the switch mounting plate my other hand happened to be touching. Could not use my arm for quite a while and did not feel very good at all. This was when I was renovating a house and went home for the day after that.
    Nev.

  4. #4
    BobL is offline Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    7,182

    Default

    Quote Originally Posted by SurfinNev View Post
    I did not know this. It was at least ten years ago now I got an almighty boot from a 240V supply, when a switch I was removing from a wall, had a loose active wire which cam out and touched the switch mounting plate my other hand happened to be touching. Could not use my arm for quite a while and did not feel very good at all. This was when I was renovating a house and went home for the day after that.
    Yeah that's a case where you should have gone and got checked out, just like I should have.

    When I was younger and much stupider I got a 6kV (limited current) shock when I was leaning over a large scientific machine and stuck my fingers inside an unguarded gap in the machine to hold myself from falling over. A number of guards had been removed and there were two of us servicing testing the machine which we had done many times before.

    The tip of my ring find touched a rubber insulated lead inside an old lab machine at 6kV and the rubber insulation crumbled and my finger touched the metal conductor.
    Lucky for me the current went down the finger and out through the base of the same finger as it was touching the earthed cabinet. The trip current was set at few microamps and we're not sure if it really tripped fast enough. Anyway the jolt threw me half way across the lab. There was a faint smell of burnt meat and my whole hand/arm felt numb. The finger turned red and then over a few hours a finger wide track or red/purple and green appeared on the skin on the inside of my finger. The skin blistered and over a day or so came away like a really bad sunburn. I also didn't report this or go see anyone and I really should have. It was the same finger I cut 5mm off the tip just a year before with a jointer.

    When we moved to 10kV gear, before testing, the "trip current" was reduced to less than a microamp and the trip mechanism was tested - got all got some small boots from that - like spark plugs boots. Eventually we set up dedicated built in test circuits and interlocks which did not even allow us inside a potentially live machine.

    I've had a few 240V boots - one in the shed was cause by looking at a tangle of cords and plugs alongside several adapter boards on a bench and assuming the one I was working was not plugged in - but it was, and should have checked the mains at the machine first, Fortunately the the RCD did its stuff.

    The worst cases are when current tracks from arm to other arm or arm to leg as that means it goes past your heart and that can lead to the worst possible outcome

  5. #5
    Join Date
    Jul 2008
    Location
    near Warragul, Victoria
    Posts
    3,718

    Default ham radio

    A guy I used to hang around was a very clever home brew ham radio nut . He had built a very nice 200 watt AM transmitter with inductive link coils for the output stage . He built a neat mechanism to adjust the link coupling . The set performed very well. I actually heard his transmissions at strength 9 during the day on the 160 metre band , ground wave over 100km distance , quite a feat .

    OK so one day he is playing around with the set, fiddling around as you do. With a total brain fade , he thinks " I wonder how hot the final tubes are " so he leans over and touches the anode on the big final tube . 1500 Volts goes up his arm , he is thrown across the room like a bag of wheat.

  6. #6
    Join Date
    Sep 2010
    Location
    Lebrina
    Posts
    1,910

    Default

    It really is a wonder the human race survives at all. We no longer need to worry about sabre tooth tigers or tyrannosaurus rex chomping us, instead we will be electrocuted by household items.

  7. #7
    Join Date
    Dec 2010
    Location
    Syd
    Posts
    492

    Default

    A mate did get a huge boot working on a live line at Port Kembla - saved by a fellow worker who shoulder charged him off. Don't recall mention of heart issues, he did have neurological ones for an extended period. His palm has something like a continuous peel of skin where he was zapped...and that's been happening for 40 years.

  8. #8
    Join Date
    Jan 2011
    Location
    Far West Wimmera
    Age
    63
    Posts
    4,049

    Default

    Ouch. I got a zap from an electric fence yesterday. Does this count? It went in one shoulder and out the opposite hand which was gripping a barbed wire as I was bending over. The short electric (temporary tape) was put in to stop my cows from destroying my fencing work before I had time to finish it. Today I plan to connect the ute / trailer to the electric fence and try to discourage them from messing with these. They are the nosiest sob's around.

    Dean

  9. #9
    Join Date
    Apr 2008
    Location
    Perth
    Posts
    269

    Default

    Apparently, electric shocks can throw your heart out of rhytm, hence the need to have one checked by a doctor. This piece of info was translated to me by a paramedic who came onto the mine site where I worked to run a safety course. Also if you take a fall and bang your head, need to get that checked out also.
    Found a chap one morning face down on the footpath, bleeding from his mouth, at first I thought he was praying, one of them odd places, people were walking around him, thing was, poor old bugger could not get up, hence the bent over position. He was in shock, had tripped from the top of three steps, stopping and asking was he ok, eyes were blank, dialled 000, ambos were quick and had him in the wagon and gone all inside twenty mins.

    DD

  10. #10
    Join Date
    Aug 2011
    Location
    Melbourne
    Posts
    4,779

    Default

    I've had a decent zap from my welder. Few years ago when I was relatively new to welding I was outside welding some plate on wet grass (you can see whats coming can't you?) Kneeling down in the wet grass I went to change an electrode and felt that beautiful feeling of 50hz through my body. Was not pleasant!

    I also grew up in a family where my dad would do all his own renovations including electrical work. The bathroom was being renovated and the bare wires from the light switch were hanging out, I must have got zapped on the arm 2 or 3 times before the switch was replaced!

    Simon
    Girl, I don't wanna know about your mild-mannered alter ego or anything like that." I mean, you tell me you're, uh, super-mega-ultra-lightning babe? That's all right with me. I'm good. I'm good.

Similar Threads

  1. X2 electrical experience??
    By KBs PensNmore in forum METALWORK GENERAL
    Replies: 5
    Last Post: 21st Aug 2015, 06:21 AM
  2. Need help with electrical issue ...
    By Vernonv in forum METALWORK GENERAL
    Replies: 11
    Last Post: 23rd Aug 2014, 06:23 PM
  3. stick welders and safety ...
    By Gedmet in forum WELDING
    Replies: 10
    Last Post: 15th Jun 2009, 09:23 PM
  4. General welding safety for DIY welders
    By Grahame Collins in forum WELDING
    Replies: 13
    Last Post: 15th Jun 2006, 02:10 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •