supplemental ground rods.

[novemberaudi]

Wired a press brake at a machine shop, 3 phase 20 amp 460 volt unit. Basically a hydraulic pump. It is a very large unit bolted to the floor. The machine shop had driven a ground rod behind the machine and had me connect a wire to the frame. The machine was used and did not have installation literature.

My question is why connect a ground rod at each machine? If it an issue of static buildup why not ground to building steel or back to the panel?

 

[GoldDigger]

Superstition.
The EGC connection will do that job properly.

Tapatalk...

 

[iwire]

A lot of machine shop equipment has computer control and the data lines were RS232 or similar that use a ground refrerance this could cause unwanted current on the data lines and data transfer failure.

People found the 'solution' was to float the macine from the EGC and put in a ground rod instead. Of course this is dangerous and a code violtion.

Legitimate solutions are isolating devices in the data lines

I think this has carried over into thinking machines need ground rods. :roll:

 

[petersonra]

It does little to solve any real problems IMO.

It will not hurt anything as long as you connect it to the incoming EGC.

 

[infinity]

It would end being something like this which as other have stated will do no harm but will provide no benefit either. This is now called an auxiliary electrode.