Broken Triac: What Went Wrong?

Without seeing the circuit diagram, its impossible to tell. Can you post the circuit as an image?

Hi friend, Please check if triac has or needs snubber components accorded by application.

İf the load is inductive also same for the load.

Try an parallel resistor before triac in parallel with doubled source for the voltage spikes.

if necessary may be use the varistor acorded the triac catalog voltage in parallel with

A1-A2 terminals, good luck

I hope it is help you.

What has already been said is good and the following please:-

You do not mention where you are or the voltage you are using, if in a 380V/220V area of the world, also make sure that your Triac is good for working for at least 1000V. More is better for top reliability!!!

Remember peaks of mountains are pretty, peaks of voltage are not!!

According to named routine, the device should be 120A and 800V. the voltage is no problem at teh situation generally speak, the problem is current, I think you'd better check your driver to see if its soft start can work well, sometimes, when ac bounding, the driver cannt form a well trace sync pulse, at some time, the second load (capacitor) resonance with leak inductor of transformer or line or rectifier's, so that the large current occur and the triac broken instantially.

According to named routine, the device should be 120A and 800V. the voltage is no problem at teh situation generally speak, the problem is current, I think you'd better check your driver to see if its soft start can work well, sometimes, when ac bounding, the driver cannt form a well trace sync pulse, at some time, the second load (capacitor) resonance with leak inductor of transformer or line or rectifier's, so that the large current occur and the triac broken instantially.

The above comments - all good guesses - are why I asked to see the circuit. If I had to guess, I'd go with the snubbing issue. It's a very common cause of power device failure. In this case, I agree with erdinaltun - an inductive load in the circuit creating a phase shift in the current would certainly cause problems for the triac, which is trying to turn off at the zero crossing of the voltage.

As Zaneka has still not let us know exactly what the situation is with regard to mains voltage & load type (why does that happen so often on CR4???) we are all guessing in the dark.

Though he did mention voltage doubler.......if only we knew what voltage!!!!

If the Triac is as stated an 800Volt version being used on 115Volts, then it will probably not be voltage peaks on the mains as I mentioned earlier, though in a dirty supply area, it is still possible.....

I also go with a probable inductive problem....

Hi! thanks for your helps, I designed a snubber with a resistor and a capacitor parallel to triac.It will solve my problem hopefully.

Let us know what the results are please, if negative, please be so kind as to supply fuller infos so that we can actually help......

Ok. Do you know how to find the pspice model of MOC3063 (triac driver) ?

Not directly, please help.