We have had a upgraded Simplex FA system installed at our college. They installed "Mapnet" wiring which is an 18ga cmp pair to talk to the heat and smoke detectors. When I opened a ceiling tile I found most of the wiring not supported and just loose above the tiles.I know code says to support no more than 48" apart. My question is where the wire enters the 4"x4" box which holds the addressable smoke detector. The contractor says you do not need to add any stain-relief at the point it enters the metal back of box at 1/2"knock-out. What is the method for having this wire go thru a metal box ? Is their code on this?
Thanks in advance.
Dan
Thanks in advance.
Dan