Grounding the work table

[CraigJ]

I am new to TIG and am waiting for my 225LX to arrive. I have a steel table that I have used for gas and stick welding in the past, frequently just clamping the work electrode to the table near the work. My question is about safety grounding the table to earth. I suspect that neither the + nor -- outputs of the welder are grounded, as the 225LX can also be used for stick on both straight (DCEN) and reversed (DCEP) polarity. If the table isn't grounded, I can see how a short in the machine might make the table hot.

I have run a wire from a new ground rod into the shop, connecting it to the ground at the outlet to give a shorter path to ground. Is it sufficient to run a ground wire (not the work clamp) to the table from the chassis lug on the back of the welder? I can also connect the table to the termination of the wire from the ground rod. Any suggestions on wire size? #6 would be needed to carry the full welder output.

CraigJ

[geezer]

I fail to see the advantage to grounding your welding table, if there is a short in the machine you already have a ground on the plug which should take care of that issue, current coming out the machine still needs to complete a circut + or neg makes no diff whether one is earth clamp or stinger. If you follow your logic on needing a grounded work table then every thing you welded would need a special ground to it before you start welding on it.

At least that's the way I see it, not to say I haven;t been wrong before, but to me grounding the welding table doesn;t make sense. Please correct me if I'm wrong on this.

[sportbike]

I don't think I have ever seen a grounded table. Not to say it may not be possible to zap yourself.

We have had HF grounding issues while welding Titanium in a computer controlled environmental chamber, but that just made the computer reboot.

[revkev6]

I don't see a need for a ground but I don't see how it could hurt either.

[67cudafb]

Really don't see need to ground steel welding table unless you have wired electric outlets or bench grinder an such then I would be sure to ground table. Be sure all grounds in shop are tied together or you create imbalance in ground field which can lead to other problems.

[performance]

Grounding the table isn't necessary nor practical.

[CraigJ]

In reply to Geezer, this is the way a welder fault could be hazardous: in normal tig setup, the machine has a short from negative (torch) to chassis. The work clamp, and the table are now at 60-80 volts above ground before the arc ignites. Could result in anything from a mild shock to electrocution, depending on how much you are sweating, what you are standing on, your shoes, etc. Maybe this is unlikely, but fault circuits are there to protect you in unusual circumstances.

Craig

[geezer]

In reply to Geezer, this is the way a welder fault could be hazardous: in normal tig setup, the machine has a short from negative (torch) to chassis. The work clamp, and the table are now at 60-80 volts above ground before the arc ignites. Could result in anything from a mild shock to electrocution, depending on how much you are sweating, what you are standing on, your shoes, etc. Maybe this is unlikely, but fault circuits are there to protect you in unusual circumstances.

Craig

Could happen, which brings up the simple safety rule, always place your earth clamp as close to your work as possible and never position your body between the earth clamp and the torch.

As far as special grounding goes I have seen old timers ground out pieces on large equipment they are welding on to prevent ball bearings on the machines they are welding repairs on from arcing. Does it help, dunno but it can't hurt.

[Spike]

When the table is grounded into your electrical wiring, you can damage your equipment in the shop if you forget to attach the ground clamp to the table. I had a metal work light during on my weld table that had a chassis ground, and I forgot the ground clamp and it toasted the light and some cfl bulbs that were on the same circuit. Regular equipment just isn't built to handle the hf start, or low voltage amperage of a welders work circuit.