Alternator temperatures

[Hayden Watson]

TICs (thermal imaging cameras) are notorious for being way off on the temps represented by the cross hairs. Follow up your concerns with a quality infrared heat gun and follow the directions on accuracy and distance from the target. I’m not saying yours is wrong (Flir is a good one) but confirm your concerns. I would never jump to a final conclusion with one but I would further investigate with more accurate equipment.

If I am not mistaken, the infrared heat guns only tell you the surface temperature which I will be getting from a thermistor mounted directly to the stator ring. The reason I wanted to follow up with the Flir is to see the temperature deeper inside the stator which will bu much hotter than the surface temperatures. Maine Sail has said before that the Ample Power alternators can be run with a case temperature of 100ºC and I am looking to veryify that at 100ºC at the case, I am not more than 140ºC in the core. My goal is to find a case temperature that will keep my "hot spot temperature" below the rated average temperature to give me some headroom.

 

[danooxnard]

The FLIR and infrared heat guns only see the surface temperature. They do not seen inside things or get core temperatures. The image is simply infrared heat that is radiated through the surface material. They do a great job of showing hot spots in electrical connections, wires bearings etc., but they are not seeing the inside temperature. They only see what radiates through, things like insulation and wood panels can slow down radiation and hide heat that is on the other side of an object. They also don’t give the true temperature of things that are shiny like stainless surfaces and metal coffee pots. What you see on those surfaces are reflected background temperatures. To see the true temp of a shiny metal surface you can put a small piece of electrical tape on the surface and the heat will radiate through the tape, and the tape spot will have the true temperature. There are lots of tricks to properly interpret images on infrared cameras and how to use them. I learned all of this in a two week course on Infrared Thermography. Flir should have some good videos on this stuff and other manufacturers too. Be careful youtube can be a friend or an enemy. Dano

 

[MikeHoncho]

Surface temps of the surface they are reflecting off of only. A further example is they do not register heat signatures on very shiny ( polished SS or aluminum) surfaces or through windows on a house.