Vent: My buddy said to always use shielded cable for long runs in that old apartment building

He warned me about interference from the old wiring and elevator motors. I figured it was overkill and ran standard 4-conductor for a system in a unit on the 5th floor. Spent two full days last week chasing false alarms on the motion sensors. The panel logs showed constant signal issues. Had to go back, pull it all, and re-run with shielded cable. Cost me an extra day of labor I didn't bill for. Anyone else get burned by skipping shielded wire in a noisy building?

3 comments

3 Comments

miles_fisher9d ago

Classic case of learning the hard way. The old wiring in those places is basically a radio station for interference.

emma_dixon709d ago

Man, miles_fisher is totally right about it being a radio station. It's not just the wiring either. Those old elevator motors throw off crazy noise that travels everywhere. I've seen it mess with a run that wasn't even near the shaft. The shield is basically a cheap insurance policy in those buildings. You skip it to save a few bucks and a little time, but then you pay it all back plus more later. That constant signal chatter will drive a panel nuts.

jasonf179d ago

My old boss at the alarm company had a rule for pre-war buildings. He said any run over fifty feet needed a shield. I saw the same signal noise issue in a 1920s hotel retrofit. That extra step with the right cable saves so much headache later.