OSHEA had a regulation about class 3 and class 2 being in conduit/cable trays. I can not find specs right now, but it stated if alarm system had more than 48 VDC they can not be in same conduit and if in cable tray they had to be 3 inches apart. That is the standard we used in the military.

I have had long cable runs of over 1800 feet(main feed within warehouse) with both in conduit, because contractor made us for foire regulations. It caused transient problems and computer/phones did not work all the time. We installed a new feed not in there conduit and allll was well.

I have also had places where alarm company came in behind us and installed in same conduit (short runs though) with no problem.

I would say it is a gamble!!

If all else fails, use a BFH.