28
Spent a full day on a bad ground loop in a retrofit
I was doing a panel swap in an old house in Tacoma last week, upgrading a 90s system to something modern. Everything powered up fine, but the keypad kept throwing a ground fault error. I figured it was a quick fix, maybe a stray wire. I spent the next 8 hours checking every connection, running a new ground wire to the water pipe, even isolating the transformer. Turns out, the old installer had run the keypad wire right next to a line voltage cable for decades, and the insulation had basically melted together inside the wall. The induced voltage was just enough to trick the new panel. Had to fish a whole new home run. Has anyone else run into a sneaky fault like that where the cause was totally hidden?
3 comments
Log in to join the discussion
Log In3 Comments
cameronm4714d ago
My last one of those was a 1940s house in Ballard. The low voltage wire was stapled to the same stud as the main feed for the furnace. After seventy years, the jacket had just turned to dust. The new panel saw it as a direct short to hot. Took me two days to stop trusting the old wire map.
9