Rant: The manual said a certain wire gauge was rated for 400 degrees, but my thermal camera told a different story

I was working on a harness replacement in a Citation last week, following the standard manual. It listed a specific 20-gauge wire as good for 400 degrees Fahrenheit continuous. Out of habit, I checked a repaired section with my Fluke thermal camera after a ground run. The reading showed it hitting 450 degrees at a splice point under normal load. I double-checked with a second probe and got the same number. It makes you wonder how often we just trust the book without a real-world check. Has anyone else caught a spec like this being off in practice?

3 comments

3 Comments

wilson.kelly28d ago

Totally believe it. Saw something similar with a supposed high-temp connector that got way too hot during a taxi test. The book is a good start, but it's just paper. Real heat and vibration don't care about the manual. Makes you check everything twice now.

bethperez28d ago

Exactly. The book is more than just paper though, it's based on real tests. Those tests just can't catch every single weird thing that happens out there. Still, it's the best map we've got for a tricky road.

ray_miller4128d ago

My old shop had a manual that swore black insulation was fine, but it melted every time.