Triac(BTA12800) failing(Short) when driving 1 ph Ind. motor

[GM2009]

In one of my application for driving single phase induction motor, I am using BTA12800 ST make Triac(two for reversing direction).But with this Triac is getting failed (shorted).What could be the possible reason that causing Triac fail?
Please reply anyone knows the reason.

 

[pranam77]

You'll find ample sub quality, sub-standared components pushed in the name of reputed brands. Confirm that your device is an original ST make with a laser engraved markings on it.
Also it is mandatory to provide sufficient heatsink to the device when connecting such loads. Also give details about how the "gate" is driven? Also curious to know wether the said circuit is a newly designed/ constucted one or the commercial make which has failed now?
Cheers

 

[FvM]

If it's a capcitor motor, turning both triacs simultaneously on (= not keeping a switchover time) is a nice way to cause pretty high currents and possbly damage the triacs. The current is at least sufficient to cause contactor welding, I've already tried. If you're sure to avoid this particular issue, the regular motor inrush current can be still too high for the part.