I have been told that it is proper to attach temporary wiring to sprinkler lines. Case in point: BX wired shop type 4'fluorescent fixtures mounted with chain to ceilings. BX feed runs down sprinkler lines attached to same with tie-wraps. Is this a proper installation?
I have been told that the NFPA 13 (fire sprinkler code) has issues with supporting things from sprinklers. I have never personally seen it in writing, however.