Set-up: New 100amp electric service, with a new 100amp rated feeder to a sub-panel indoors. Neutral and grounds seperated in sub-panel. Wiring to range and dryer was not replaced, and both consist of copper se cable, with 2 insulated conductors, and an uninsulated conductor wrapped around the insulated two. Electrician landed these to the neutral bus in the sub-panel, but they are still bare, and can touch the enclosure.
What are my options? Tape up bare conductor, and leave on neutral bus? Leave them bare and land them on the grounding bus? Require complete replacement of cable to a 4-wire cable?
If you can't replace them, taping and leaving on neutral bus is much better of two less than ideal options. This doesn't meet current code, but is not much different than what was permitted for years until a few codes ago. I know it is not the service equipment, but as long as neutral bus is isolated from grounds, it seems to be just a junction point.
I don't think there is any specific justification for this in the code. I believe that it is however a popular solution to insulate the Bare conductor and land it on the Neutral bar, making sure that some unbroken sheathing extends through the clamp/connector into the Panelboard. This way it will not raise the potential of any exposed metallic parts.
It's a good compromise in my opinion. I'd say it's much better than allowing 3 wire service to remote panelboards because they are existing. (This has been discussed before). Perhaps you can check at IAEI BB to see what other AHJs' are allowing under these circumstances.
[This message has been edited by Bill Addiss (edited 05-24-2001).]