Ran 22 gauge wire on a 30 foot run for 6 years, one panel swap in Tulsa finally showed me
Always figured 22 gauge was fine for door contacts since the runs were short. Then last month I ripped out an old panel in a Tulsa rental and the voltage drop on a 30 foot run was so bad the zone kept tripping at 2am. I stood there with my meter reading 9.1 volts and just laughed at myself. Turns out every one of those callbacks I blamed on bad magnets was my own wiring. Anybody got a rule of thumb for when you actually bump up to 18 gauge?