Almost fried a whole house after a bad ground loop

I was installing a DSC system in a new build in Austin last Tuesday. Everything was going smooth till I connected the panel and saw smoke coming from the keypad. I ripped the battery out and checked my wiring three times before realizing the transformer ground was sharing a circuit with some HVAC equipment. That ground loop sent 24V AC straight through the data line. Had to replace the main board and keypad, cost me about $150 out of pocket. Any of you guys run into weird ground issues on new constructions with shared neutrals?

2 comments

2 Comments

juliagonzalez1d ago

Laughed out loud reading this because I did basically the same thing on a job last month, only I caught the smoke before it got too bad and just had to replace the keypad. I mean, its funny how a brand new build can have the jankiest wiring ever if the electrician had a long week.

grayperez20h ago

Sloppy wiring in new builds is way more common than people think. I started taking photos of every junction box before I button things up, helps me remember what I actually did in there later.