Mig / Tig "Earth"

[Damaged]

Hi all,

Not sure how stupid a question this is but am I going to damage either of my sets by having the -ve of my mig connected to the same weld bench as the +ve of my tig?

May be a daft question but I'd rather ask it than trash one or the other...

Many thanks,

Mick.

 

[JW240]

i would disconnect the un-used machine. Once i left my plasmacutter's ground lead connected to a plate i was cutting and attached the tig ground lead to it, the tig machine took longer to start up and the indicator for mains error (or something like that) didn't go out as fast as usual. Didn't sound great. The machine still works good, but you never know.

 

[Damaged]

Thanks for that,

Would this still be an issue if I fan a true earth (say 16mm cable) from the bench back to the distribution board or could this make matters worse?

 

[bucko]

why not just youse a clamp on the table and keep things simple?

(i'm not beeing funny im trying to learn too)

 

[knoba]

I guess it'll depend on the circuitry of the welders and how important it is to have a direct route to their own earth returns. Re-routing the return feeds sound's a bit dodgy to me.

 

[peterd51]

Hi,

it shouldn't cause any problems connecting the bench to the mains earth point as everything that's metal, such as benches and shelving, should be earth bonded anyway.

Having said that I've been meaning to get around to grounding my benches for some time and I've not had time yet!

Regards
Peter

 

[Damaged]

Thanks Peter, will connect it up at the weekend.

 

[bucko]

why would you wont to do that ??
could some one please explane

 

[peterd51]

Hi,

if something goes wrong with electrical equipment then the metal case may become 'live'...think of a loose wire at main voltage floating about inside a welder. It should never happen but it could do.

Also consider a grinder left powered on with the cable across the bench and a sharp tool is dropped onto the wire. The tool breaks the insulation and the metal bench now has mains voltage on it.

Again, it should never happen, but it could.

So everything that's metal such as the bench, Dexion shelves, welder chassis, pillar drill base, etc, should be earthed just in case.

Regards
Peter

 

[bucko]

ok makes sence now thankyou very much for takeing you time to explane that to me

 

[bucko]

feel stupid now for not reilseing that its so obviouse aswell

 

[Robotstar5]

feel stupid now for not reilseing that its so obviouse aswell

It's better to feel stupid than not feel anything ever again if you have an accident due to bad practice!