Debate: Do you wire motion sensors in series or parallel for large open rooms?

I had a job last month at a warehouse in Cleveland, 40 foot ceilings. Client wanted full coverage on the floor. I wired four motions in parallel like I always do, but the first false alarm from a space heater had me pulling my hair out. My partner said he swears by series wiring for big rooms to cut down on nuisance trips. But then you lose the individual zone reporting on the panel. Which way do you guys go for open layouts with lots of environmental noise?

3 comments

3 Comments

kevin_west18d ago

Parallel and then throw a zone doubler on the input for troubleshooting.

craig.mila18d ago

Huh, I used to be team series all the way but you just changed my mind on that.

young.nora17d ago

Swear to god, I spent three hours troubleshooting a parallel setup in a gym last year before I realized the HVAC vent was triggering the damn thing. So I’m biased toward parallel just because I hate chasing ghosts in big rooms later. But I totally get why you’d want series to cut down on false alarms from space heaters or the sun hitting a window. Zone reporting matters though, especially when the client wants to know if the back corner is a raccoon or a real person. Honestly, I’ve been burned so many times I just parallel everything and accept that I’m gonna get one false alarm a month and mutter about it over coffee. Maybe I’m just lazy, but I’d rather troubleshoot one dumb heater than lose zone info.