you need to use interlocks to prevent invalid states

Can you explain more, or suggest an example to prevent simultaneous activation of two triacs when connecting and disconnecting a phase (380V)?
I will be very grateful to you

 

Back up a bit. You said it blew up without a motor attached. The devices are being turned on somehow and trying to connect 2 phase lines directly together, with nothing to limit the current, which is disastrous. There are either electrical leakage issues, or maybe even light leakage issues.

 

The explosions are probably due to excessively fast dV/dT causing a turn on when it should not happen. That is an old problem, I am not aware of the solution. My fix is simple but really hokey: use three triacs for RUN/STOP control, and a 2-pole mechanical contactor for reversing. The reversing contactor does not ever make or break current and so it is cheaper by quite a bit. Not a good scheme but it works reliably. Unless the power fails and the reverse contactor drops out while running.

 

Bro what watts is 510 ohms resitor

 

10nf what voltage?

 

Can you explain more, or suggest an example to prevent simultaneous activation of two triacs when connecting and disconnecting a phase (380V)?
I will be very grateful to you

Hi dears

I wanna control the direction of a 3 phase AC motor. there are two types of circuits for it.
View attachment 244147
and
View attachment 244148

the lines voltages are 400 volts and I choose BTA12-600CW.

1. The 600 volts for BTA12 is enough or do I need a higher voltage TRIAC for the purpose?
2. It used 5 TIRACs in image 1 and 4 TRIACs in image 2. is the TRIAC 1 necessary in the first image?
3. I choose the second schematic for lower component reasons. But I have some heavy crush in the test circuit. the burnt TRIACs are No one and three (from top to end) or No two and four. It's not always happening but it happens anyway. why?
4. I use a 100 ohms resistor and 100nf capacitor as a snubber network. Is it proper?

thank you for your suggestion.

What watts 510 resistance u sed and what voltage rating for 10nf sir?

 

Any circuit plz

 

Let's talk about your 380 Volts. Is that source a Y or Delta? Is that the voltage line-to-line, or line-to-ground? Is that 380 RMS or Peak-to-Peak?

 

You do know the thread is 18months old ??

 

No. Just received the notification and ASSumed it was current. Wonder how it worked out?