When passing from an unclassified location into a Class1 Division1 location, conduit seals must be installed within 10' of the wall separating the 2 areas. See 501.5 (A)(4)
What about MC-HL cable?
501.5(D) addresses cable seals, but does not address seals at Classified/Unclassified boundaries. Should 10' be assumed? I believe the 10' limit is due to the fact that conduit comes in 10' lengths, and since no fittings are permitted between the barrier (wall) and the seal anything over 10' would necessitate a coupling or union. MC-HL cable however, is available, unbroken, as long as needed. Would a cabinet located in an unclassified location need to be close enough to the wall to have a maximum of 10' MC-HL, (which would then be terminated in a MC-HL sealing connector at the cabinet)?
BTW, the '02 Handbook is useful for this discussion.
[This message has been edited by Redsy (edited 10-04-2002).]