Ground drill ?

[jimbo123]

I have seen the results of a drilling rig that bore holes in the ground and by chance hit underground feeders , we know that engineering should prevent things like that by having a survey completed before the work it started. [Poor planning]
My question would be should the drilling equipment be grounded ? This could be large portable equipment taken from site to site by truck.
It's possible to strike one phase first before contacting either the second phase or the egc , cables could be run in pvc conduit. 500amp <600v
Thanks for responses with this.

 

[dereckbc]

The problem I think would be could you get the impedance low enough to do any good (operate OCPD) on low voltage feeders below 600 volts. You would have to get to 1 ohm or less. That is almost impossible.

 

[jim dungar]

The problem I think would be could you get the impedance low enough to do any good (operate OCPD) on low voltage feeders below 600 volts. You would have to get to 1 ohm or less. That is almost impossible.

Especially if the OCPD's 'ground rod' is already >1ohm.