New three phase range but no ground.

[oldbellguy]

400 Amp three phase main, 120/240v, 205v high leg, with neutral grounded at the service entrance. No individual grounding conductors and old style three phase panel with no grounding buss. 200Amp sub-panel serving three phase loads as well as receptacle loads, having their neutrals and grounds landed on the sub-panel neutral buss. The old range was not grounded. New range must be grounded, but 250.140(1) prohibits using the neutral for grounding. Considered routing individual ground wire from the grounded service entrance neutral buss out to the range but not sure if that would meet requirements. Opinions /Suggestions Please.

 

[LarryFine]

Replace feeder or add EGC alongside existing. The sub-panel itself also requires correction, including isolation of neutrals. Technically speaking, however, an "existing installation" does not require updating, if it was compliant when originally done. If this is not a new range circuit, it may be compliant as is.

Added: I hope you're qualified to post here.