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Bit of a belt!
Posted: Sun May 13, 2018 3:19 pm
by Jonno34
I was doing a bit of a repair on a metal railing at home. I had been welding on a different section so the welder (Stick) was on and on a highish setting. Whilst connecting the earth clamp I brushed my arm on the railing and got a bit of a belt (electric shock). Nothing was connected other than the earth clamp. This gave me a big question mark. I checked out the welder after and noted that there was a bit of bare wire where the feed wire for the stick end comes through the chassis which I repaired. The only thing I can think is that this feed was running to possibly dampish ground into the wall and into the railing, the circuit being made when my are which was holding the clamp touched the railing and belt! Does this sound feasible?
The other thing that surprised me in there is no mains earth on the welder?
Comments appreciated!
Re: Bit of a belt!
Posted: Sun May 13, 2018 6:27 pm
by moderator7
I've moved this to the electric forum, as it's more of an electrical question than a metalworking one.
Re: Bit of a belt!
Posted: Sun May 13, 2018 9:09 pm
by Someone-Else
(Since I don't know) How do you know your welder has no earth?
Re: Bit of a belt!
Posted: Mon May 14, 2018 4:09 am
by Jonno34
Maine 3 pin plug has 2 wires, live and neutral.
Re: Bit of a belt!
Posted: Mon May 14, 2018 9:49 am
by Dave54
Far Eastern import?
Inverter or transformer?
I thought welders had to have an earth on the supply side.
I'll have a guess that the voltage on the welder is "floating" with regard to earth potential.
So the welding "earth" may be above the potential of the actual "Earth" which your railings were probably at.
Hence the shock from welder "earth", which because it's not actually connected to earth (see ETA below) can be at a voltage above that, to actual "Earth"
There's usually something like 40-50 volts on a normal DIY type welder, can be more particularly on heavier kit, so it is enough to give you a shock.
ETA As far as I know, or can find out, the welding current leads should not be electrically earthed as this would potentially allow any electrically earthed metal to be welded without applying the welding clamp earth, which would cause high currents to flow in the mains earth.
As always with electrical equipment, if you are getting shocks off it you should get it properly checked out.
I'd want to know what the voltage is, and exactly why the shock occurred.
There an HSE leaflet here about safety with electrical welding gear
http://www.hse.gov.uk/welding/electrocution.htm
and a bit about electrical earthing of welders here
http://www.lincolnelectric.com/en-gb/su ... etail.aspx
Re: Bit of a belt!
Posted: Mon May 14, 2018 5:41 pm
by Someone-Else
Jonno34 wrote:Maine 3 pin plug has 2 wires, live and neutral.
Fair enough, but here is my question, if it has a plug which you can open, could it be the lead has been changed since "appliances" have had to have a fitted plug for years. (99% opt for a moulded on plug as its cheaper) or perhaps some one cut the earth wire too short.
Is there anywhere on the welder a symbol which is a box in a box?
Re: Bit of a belt!
Posted: Thu May 17, 2018 5:29 pm
by Jonno34
It has had the plug since new. The machine is Ersin a Turkish company and I am based in Cyprus if that explains things a little better.
Re: Bit of a belt!
Posted: Thu May 17, 2018 8:36 pm
by Someone-Else
Jonno34 wrote: The machine is Ersin a Turkish company and I am based in Cyprus if that explains things a little better.
It does.
I /we were under the assumption you were in the UK (You do not have your country of residence listed) so everything you were asked is in reference to UK wiring regulations, which clearly do not apply in Cyprus.
Re: Bit of a belt!
Posted: Fri May 18, 2018 10:32 am
by Jonno34
That said it does not detract from the original question:-
How did I get the belt? How was that circuit made?
Should this machine have a mains earth?