Loading…
0
Old tech's grounding trick kept my bench tester from lying
Honestly, a senior guy at my last outfit in Tucson told me to run a dedicated ground wire from the test jig straight to the aircraft's static ground, not the bench's outlet. I thought he was being paranoid, but after I wired it his way, my resistance readings stopped drifting by 15 ohms on the same connector. That loose neutral in the building was throwing everything off, and I didn't catch it for two days. Anyone else fought phantom readings from a shared ground loop on a harness tester?
1 comments
Log in to join the discussion
Log In1 Comment
shane_morgan17d ago
Yeah, the "dedicated ground wire" thing is real. I've seen the same kind of crap with my own multimeter at the shop when I'm testing a car's resistance and the building's AC kicks on. The voltage just shifts and suddenly my readings are off by 10 or 20 ohms for no reason. It's like the whole building's wiring is one big messy net and everything bleeds into everything else. That's why I keep a separate ground wire tied to a real earth rod outside now, not the outlet. It's the same story with home audio gear, people plugging a guitar amp and a computer into different wall sockets and getting a nasty hum. You just can't trust the outlet as a true zero, you always need a solid reference point that's actually tied to the dirt.
6