Stopped by a new construction site and saw a mess that worried me

I was at a custom home build in the suburbs last Tuesday and noticed the alarm wiring was run right next to the main power lines in the attic, no separation at all. That's asking for signal interference down the road, has anyone else seen installers cut corners like that?

2 comments

2 Comments

taylor.jessica1mo ago

20 years ago I had the same thing happen on a spec house in Oak Park. The alarm guy just stapled his low-voltage wire right alongside the 120-volt Romex in the attic. After the homeowners moved in the motion sensors would false trigger every time the AC compressor kicked on. I ended up having to pull all that wire out and re-run it with at least 12 inches of separation. The electric code doesn't spell it out clearly for low-voltage stuff but the National Electrical Code Article 725 does say you need to keep Class 2 and Class 3 wiring separate from power conductors. For anyone dealing with a new build I would get a cheap toner and probe and test the alarm wires while the power is on. If you get a constant hum on the line you will be chasing ghost signals forever.

caseyw121mo ago

The part about the motion sensors going off every time the AC kicked on is crazy. 20 years is a long time to deal with that kind of noise on the line.