TIL hardwiring a motion sensor backwards can fry your panel

Was installing a Honeywell DT900 for a client in a new build out in Oak Park last month. Got the wiring all hooked up and powered on the panel, and instantly smelled that burnt electronics smell. Turns out I mixed up the common and power terminals on the sensor. Fried the zone input on the panel board. Had to eat the cost of a replacement board and drive 45 minutes back to the supply house. That was a $220 lesson. Has anyone else smoked a panel from a simple wiring mistake?

2 comments

Log in to join the discussion

Log In

2 Comments

julia8434mo ago

The part about eating the cost hit me. You know what gets me though, is nobody talks about how these newer panels don't even have proper fuse protection anymore. My old Ademco had glass fuses that would pop before anything got real fried.

0

fiona_scott444mo ago

Right? I once had an old panel die so spectacularly it basically nuked itself, like a tiny smoke show in the basement. I'm pretty sure I could have fixed it with a dime and a prayer back then with those glass fuses. Now everything's surface mount and good luck finding a replacement part that doesn't cost more than a whole new board. My luck I'd try to fix it myself and end up accidentally grounding out the whole neighborhood cable TV line. Guess we're all just one power surge away from a very expensive lesson these days.

2