Spent 4 hours chasing a ground loop in a new build yesterday

Ran a whole home network drop for a customer in Easton. Everything tested fine on the meter but the modem kept losing sync every 15 minutes. Thought it was a bad connector so I re-terminated both ends twice. Then I checked the bonding at the panel and found the ground wire from the DEMARC was sharing a lug with some HVAC equipment. Moved it to its own lug and boom, problem solved. 4 hours of my life because some electrician was in a hurry. Has anyone else had a similar issue with shared grounds messing up signal stability?

3 comments

3 Comments

carr.abby16d agoMost Upvoted

Was the HVAC guy's ground wire just flopping on the lug or actually torqued down?

spencer_gonzalez116d agoMost Upvoted

Ha, you’d think it was torqued down but more like it was just kind of hanging there saying "hey, I’m doing my best." Probably the same guy who uses a rock as a level. I’ve seen some hack work in my time but that’s a new kind of lazy.

grantw4116d ago

Wait, was the HVAC ground wire actually sharing the same lug or just on the same bus bar? Ngl, that detail matters because a lug usually means one wire per hole on the bar, but a bus bar can have multiple lugs stacked. If they were pinched together under the same screw, then yeah that's a real problem with the bond. But if they were just on the same bus bar, that's usually fine as long as the bar itself is bonded right. Honestly, I've had to chase voltage potential between two separate bus bars before, that was a nightmare.