Two welders, one bench....

[Davek0974]

If I'm only using one at a time, is it safe to connect the ground clamps from Mig (DCEP) and Tig (DCEN) welders to the same welding bench together?

Both machines would be connected to the supply but very unlikely both would be switched on at the same time and as I'm in the shop on my own, only one could ever be used at a time.

Both machines are inverter types.

 

[chunkolini]

I used to do this.
But somewhere in the distant past I picked up a reference to HF from the start working it's way up return leads and discmbobulating circuits.
Cant remember where or when, might be absolute cobblers but I try not to have my plasma cutter and mig attached to the same surface.

 

[Davek0974]

Ok, thanks, I'll only ground one at a time then.

 

[fixerupper]

That still confuses me ,for example on a ship in a ship yard there is maybe 20 or30 welders buzz away all day and they have all got the earth clamp on the same bit of metal ...the ship.. and I've worked on fit ups in the theatre and we often have two or three welders on the same set... should it be avoided ?....jeff...

 

[Robotstar5]

I think it's where HF start is used that can cause problems.

I have previously built some robot welding cells with 2 TIG welding robots working on the same part, had a few problems with the HF from one weldset interfering with the other set

 

[BrokenBiker]

we have a bench in work that has about 5 welders on it, mig arc and tig and they seem to get along fine, although the tig is ancient and the mig and arc sets are about 5 years old, maybe its just luck, or maybe they don't tig at the same time as anything else.

 

[dannyp]

with proper migs there is no issue with haveing multipul machenes on the same job, at work when in a rush we've had 3 nigs all eatherd to the same metal frame and all welding on it at the same time no problem. have had an inverter arc welded going on the same workpices as a mig both welding at the same time and no problem

Tigs are the onl ons that can cause issue ever had problems with DC but if useing a tig on ac the one mig (newest) gets a really upset

 

[Davek0974]

In theory there shouldn't be any issue if the output leads from the welders are completely isolated from the supply grounds, no loop can be formed then. I haven't looked at the diagrams for my machines so can't comment if this is as it is.

Luckily, both my machines have the same dinse plugs on the leads so a solution was easy - get rid of one earth cable and simply swap the earth from one machine to the other when needed, one cable less dragging across the floor too