Finally caved and bought a thermal imager after years of guessing

I was at a supply house last Tuesday and overheard a contractor saying he never uses his multimeter for compressor checks anymore, just points his FLIR at the lines and can tell if it's a bad start cap in 5 seconds. That stuck in my head. Got a cheap 300 dollar unit off Amazon and tried it on a fridge that was cycling off too fast. Sure enough, the compressor was way hotter than the condenser outlet. Replaced the relay and it's been running fine for a week now. Anyone else ditch their clamp meter for a thermal cam on certain calls?

2 comments

2 Comments

dianab6825d agoTop Commenter

Yeah but hold on, a thermal cam won't tell you if a start cap is bad directly. You're reading the heat from the compressor struggling, not the cap itself. A bad start cap makes the compressor draw high amps and overheat, but the cam shows you the outcome, not the cause. I still grab my clamp meter to confirm the run cap is within spec and check the start cap for a bulge or use a capacitor tester. Thermal imaging is great for spotting high resistance connections in breaker panels or finding a hot neutral though. Just saying, don't toss your multimeter yet.

nelson.finley25d ago

Man, that's a really good point about still needing the clamp meter. I feel the same way, thermal imaging is just one tool in the box, not the whole answer.