Managed to get my hands on a awesome tool, which also just so happens to be my new phone.
Got the new Cat phone, mainly for its FLIR Lepton 3 sensor, and what a cool (pun intended) tool this is, especially for any electrical or solar work, or even just for playing around with electrical motors, like I do.
Very first scan was of my solar panels, checking for any hot spots. Luckily none found, but will keep checking every year, just to be sure.
What is extremely handy is you can take the thermal picture and later edit and add multiple measurement points, as the image is saved with the full thermal gradient information, You can also vary the opacity of the background, to make the outlines of the objects in the photo stand out.
I saw your first photo’s, and immediately was going to tell you tho check your heavier current connections on your batteries.
But I see you got there ahead of me.
My guys are equipped with a flir as part of their standard tools for this exact reason.
Interesting. Currently I’m busy with construction at my house (while living here with a 1 year old, she was 6 months old when it started - not recommended) so the electricians are just completely messing up my insulation. I’m not going into the ceiling anymore, because I just get worked up. When this is done, I’m going to see if I can borrow something like that and identify the rooms that need some work.
Question: In the summer, the hot spots are probably an issue, but in the winter, wouldn’t the cold spots be the issue? Wouldn’t that indicate where the cold air from outside penetrates the insulation and cools the ceiling board itself (subsequently cooling the air close to the ceiling which then drops down and makes your feet cold!)?
Conversely, the hot spots are good because that indicates your room heating up but not losing that heat through the insulation in the ceiling?
Yes, I agree, was more referring to the picture that indicates spots of “goodness” while most of the ceiling seems “bad”. I would’ve expected it to be the other way around (unless there literally isn’t any worthwhile insulation).
DC wires running between MPPT and batteries can quickly reach 50deg…
In the mines we started looking at Temps above 60deg, we did Thermal surveys on a yearly basis and the reports flagged connections or wires above 60… From there my reference points.
Your experience please?
EdIt: I just Google the temp rating of common cables and the general max rating is 90deg with some cables rated at 60deg. I guess that was where the 60deg standard in the mines came from. Personally I have seen that just about every single Flir image has got “hot spots”, I am normally not really worried about anything below 50deg. I will however do a thorough check and try to rectify anything above 50 on a solar system.
I have busbars, considering just the positive busbar I have :
2* 25mm cables to 2 80A MPPT’s
2 16mm cables to 2* 60A MPPT’s
3 * 50mm cables to a 5kVA Phoenix ( used to be 24V, and I used the same cabling)
4* 50mm cables to 2 * 8KVA Quattros
16 * 25mm cables to batteries.
Various 50mm loops as the busbar is in 3 sections.
All of these cables are lugs and on studs with washers and bolts. Anyway you get the gist, plenty of connections.
My experience is that a poor lug ( originally I didn’t have a hydraulic crimper) or a not tight enough nut isn’t picked up visually, but over time with 300A+ on those busbars, it certainly makes itself known. My busbars are on insulating posts and these melted once before (So, not 26 degrees no).
I suppose it isn’t about what the absolute temperature is (within reason), but what the relative temperature of the connections are. A connection that is way hotter than the norm would identify a potential issue.
As a matter of interest, overhead power lines are load-rated to a theoretical 95 deg C. ( I think a 5km/h breeze is assumed).