Electrical shock question

[Marc88]

Hey guys,

Complete electrical newb here. I'm an automotive guy but will be getting into mig arc welding.

Due to the voltage used in welding I'm curious to ask... If you touch the electrode wire coming out of the feed, when the welding machine is on, will you get a shock? And why? This is assuming you're not touching any metal or ground wire...

Sorry if it's a stupid question. I'm just a big time newb. Thanks!

 

[rtbcomp]

Welcome to the forum.

A MIG welder shouldn't give you a shock if you touched it with dry fingers, but will give a serious jolt if you touched it with your tongue.

The welding return (AKA Earth) is in fact not connected to the case or mains earth so there won't be a return path unless you are touching the "earth" clamp at the same time you touch the wire.

Basically, it's perfectly safe as long as you respect electricity and don't fool around.

 

[TurtleDude]

How did someone find out that licking it caused a shock?

 

[rtbcomp]

As kids we used to put 1-1/2 volt batteries on our tonges and got a slight shock.

 

[slim_boy_fat]

As kids we used to put 1-1/2 volt batteries on our tongues and got a slight shock.

I remember doing that - I thought I was the only daft one still living today.......

 

[pedrobedro]

How did someone find out that licking it caused a shock?

Whatever you do don't buy a chainsaw Silver foil on your metal fillings was always a good dare, that's something you don't do again on purpose.

 

[gordon stephenson]

Im a tongue tingler too, Was the only way we had to see if there was any life left in a battery, Particularly the square flattish ones that had two long brass contact strips on top, Don't know the number but you don't seem to see them now,

 

[TurtleDude]

Whatever you do don't buy a chainsaw

Ha, got three of the blighters. Never felt the compulsion to lick them though..

 

[Shedendman]

As kids we used to put 1-1/2 volt batteries on our tonges and got a slight shock.

All part of being a kid wasn't it?

 

[gordon stephenson]

pdg, thats the one, 3R12- 4.5 volts. ( just googled) Flat torches and bike lamps as I remember,

 

[HughF]

15v open circuit for the low end on hobby migs, up to around 25-27v at full power for a 200A machine. You won't get a jolt off that at all...

 

[HughF]

If you lick it, you deserve it...

 

[Maker]

You feel the tig's high frequency arc if you forget the ground clamp.

 

[HughF]

We're talking mig machines here people... CV, not CC

 

[Marc88]

Welcome to the forum.

A MIG welder shouldn't give you a shock if you touched it with dry fingers, but will give a serious jolt if you touched it with your tongue.

The welding return (AKA Earth) is in fact not connected to the case or mains earth so there won't be a return path unless you are touching the "earth" clamp at the same time you touch the wire.

Basically, it's perfectly safe as long as you respect electricity and don't fool around.

Thanks for the response... I thought that would be true. You would need to close the circuit by touching the ground clamp as well as the electrode, right...

But how would touching the electrode alone on your tongue close the circuit? I know the resistance would be less but I thought it would still need to find a way to ground wire to allow the electric current to flow through you?

 

[rtbcomp]

Thanks for the response... I thought that would be true. You would need to close the circuit by touching the ground clamp as well as the electrode, right...

But how would touching the electrode alone on your tongue close the circuit? I know the resistance would be less but I thought it would still need to find a way to ground wire to allow the electric current to flow through you?

Yes you'd need to complete the circuit via the ground clamp.

In theory just touching the tip with your tongue wouldn't complete the circuit, however in practice there is a path to earth via capacitance. Regard the planet as one plate of a capacitor and the "earth" clamp as the other so there is path through this "capacitor". The output of a MIG is DC so there wouldn't be a continuous flow of current (unless it was unsmoothed), but you might feel something as the "capacitor" charged up.

The effect of this ground capacitance would be increased if the ground clamp was connected to a workpiece or a welding table.

If the workpiece itself was earthed (an RSJ in a building for example) there could be a path to earth due to resistance, which could allow a DC current to flow through your body, but again your boots should prevent this.

All this is highly theoretical - in practice you are perfectly safe - just don't go licking the torch without any boots on and one foot dangling in a garden pond.

 

[ms08]

I believe the little 9v dry cell battereis have been know to kill before now if touched on the tongue - more likely i guess if you have a weak heart.

 

[TurtleDude]

I believe the little 9v dry cell battereis have been know to kill before now if touched on the tongue - more likely i guess if you have a weak heart.

Makes mental note to stop licking batteries, welders and chainsaws.

 

[rtbcomp]

^^ You can keep licking chainsaws if you keep your tongue away from the HT lead.

 

[roofman]

You feel the tig's high frequency arc if you forget the ground clamp.

you also feel the tigs HF iff you air start next to a magnetic clamp and your holding it..magnet drags the HF right to it and into your finger