neutral isolation and bonding

[vango]

which code cycle did the isolation of the neutral to the equipment ground/grounding electrode conductor of a remote and/or sub-panel begin?

 

[augie47]

If the sub-panel is in the same building, the requirement goes way back. Oldest Code I have on hand is 1990 and it was required then.
If the sub-panel is in a separate building, the requirement for a grounding conductor (as opposed to using the grounded conductor) came in the 2008 NEC.

 

[tom baker]

not being able regrounding the neutral for panels in the same building goes way way back.
Seperate buildings the prohibition started with the 2002 NEC with sometimes and then finially the 2008 NEC said never.

 

[Sierrasparky]

So do you think it came about in the 80's.