I use the TEC modules to heat a plate.
Temperature is controled by PID control, and the temp is set at 149 F.
When the temp reached 149, the current is reversed.
But I just measured a few times, TEC modules is broken without reason
Look forward to your advice from the forum.
Thanks!

 

Welcome to the AAC forum.

No one can answer your question without more data. What was the current, and what is the max current spec of the TEC? These devices are vulnerable to thermal shock. Perhaps reversing the current caused a thermal change in excess of what the TEC could tolerate. Or maybe it overheated due to inadequate heatsink?

 

Thermal shock is also what I think would cause the failure.

TEC's will rapidly fail if you subject them to sudden reversal of current flow.