Triac problem - Can you spot a problem in my design?

[baba_sanfur]

Triac problem

Hi all,
I am working on a circuit needed to be operate by triac. The current suppose to be around 16A (AC).
I build the following circuit (attached), to test the heat produce by the triac.
The triac rated as 25A(Q4025R5, littlefuse), and I tested it with ~7A. the triac got very hot!

The prosuct I'm working on will switch appliance on and off, at current of ~16A. Is it feasible to use triac?
Can you spot a problem in my design?

Thanks,
Nir

 

[umery2k75]

Re: Triac problem

There are number of good possibilites.You triac is not getting 100% turned On.Let's say 50-80%. It's juction would be getting severly hot, just because of this. You need to apply ample amount of current, see it's datasheet for the requirement of gate current.You need to apply the correct amount of gate current for the correct amount of TIME, for it's proper operation or else it will start getting heat up. Another reason, See if your load is being operated in a right quadrant I,II,III,IV. Check if interchanging Phase and neutral doesn't disturb your load.If it distrubs, then check if you are appling single phase AC voltage by keeping in mind the phase and neutral are correctly installed into the correct position into your system.

An advise:
Mostly such circuit's are used with zero cross detection. You will not be knowing at what part of the cycle you just turn on your TRIAC. It's not good for it's health.Still your TRIAC won't get heat up. It would bring spikes into your line.