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cdru
.75mm is inbetween 18 and 19 AWG and would be right at the very edge which what you should use. They likely are getting warm if you're running them non stop.Quote
ianmcmill
I am using ordinary ceiling lamp wires (german ones with 3 braided wire). They are 0.75mm² which is like something inbetween AWG 20-21. Maybe they are too thin ?
What is the resistance of your bed? The specs claim 1.4-1.6ohms configured for 12v, which is on the higher side for heated beds. That translate into lower power requirements and less heat given off. That, combined with the Al core means the less heat it does produce gets spread around a lot more, as well as radiated more. The metal core is nice as it helps keep even heat and can temper any minor momentary fluctuations in heat...however it takes and more to heat up and to maintain that heat.
Oh yeah I mistook diameter for area.
Okay so after 25 minutes it reached 100°C. The heatbed has 1.9 ohm resistance. 0.3 more than they say in the datasheet.