The NEC has guidelines for how much wire fits in a conduit,
but it is mainly concerned with heat build up. The concept
is that once that is satisfied, pulling the conduit through
is just a matter of using sufficient force, sufficient
lubricant, and sufficient number of pull boxes. Stress on
the wire being pulled isn't an issue, because it's just
dumb wire that can't be screwed up.
I heard of a project where coax was pulled through conduit
by union electricians who went by the book. Beautiful
looking job, but all the coax was damaged by the stress
of being pulling. Had to do it all over again with
larger conduit. The electricians didn't know any better.
They thought wire is wire.
Bottom line: use really large conduit for coax. The
bends have larger radius. The pull boxes are much larger
so you don't mangle the coax. Don't use pulling elbows.
Rick N6RK
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|