My kayak project is coming together and undergoing testing. Running at 16V and almost 20A, the wire from the thruster gets much hotter than I expected. 90°C! This happens to both thrusters. Is that normal? The wires are only hot where they are insulated. The small amount exposed at the connector to the esc is not hot at all.
Yes, this is normal, all cables will heat up from current passing through them.
In most applications using our thrusters, the cable is either fully immersed in water, or the thruster is not used at such a high duty cycle for extended periods. In either case, the cable does not heat up as much, running them as you are on a kayak will result in the highest cable temperatures.
Depending on your design, this is fine and will not result in cable or thruster damage at 16 v. However, if there is a risk of accidentally touching the cable while it is hot or overheating other components around it, I would recommend at least tucking it away or putting a cover over it. You could also cut it short and splice on a thicker lower gauge cable as well to reduce the heating significantly if you wish.
Thanks Adam. That puts my mind at ease. The cable is inside an aluminum tube which is good because the kayak is a Hobie inflatable. I’m not sure how well the pvc hull would hold up with sustained temps that high.
I may shorten the cable like you suggested but I’m inclined to keep them longer for any future projects that may benefit from the length.