Ground Rod purpose in industrial setting - welding equipment

[bschauer]

I work with welding systems that are connected to ground rods installed inside large buildings. A hole is drilled into the floor and a rod driven into ground, then bonded to the machine frame. It also seems to be a requirement for plasma cutting tables. I have asked what the purpose of this practice is and I cannot get a consistent answer. Many different opinions and some seem plausable, others do not. Is there aanyone out thtere that knows the engineering behind this practice.

 

[augie47]

Here is a link to an earlier thread that includes a video from Mike on the subject:

http://forums.mikeholt.com/showthread.php?t=157957&highlight=CNC+Machine

 

[dereckbc]

It serves no purpose. The only purpose it could possible serve is if the building is a steel structure with all the steel bonded together would allow a welder to weld on the building structural steel without using the ground clamp on the welder unit. Would be very stupid and irresponsible to do that as it could burn a bonding jumper up with over current.