Low voltage (480V) personal protective safety grounds

[cornbread]

I had asked this forum earlier about the need to apply safety grounds on 4160V motor starters with armored cabled....many thanks for the replies. My next question is the application of personal protective safety grounds on 480V motors. The standards seem pretty vague.

NFPA 7.7.1 Sound engineering judgment should be exercised in deciding the extent of protection to be provided...

What is everyone else doing on 480v motor circuits?

 

[zog]

Chances are you available fault current is higher than any groud set rating so it is a false sense of security. We only apply ground when working on MV systems.