thyristor checking

A

Thread Starter

Anonymous

How to check whether thyristor in the circuit is healthy or not?????

Please extend ur view on this.
 
T

T.N. Natarajan

Remove the Main Power from the circuit
Release Pulses from the Firing Card
Check the Firing Pulse at Gate of Thyristor with Oscilloscope.
If the Pulses are absent check pulses before Pulse Trasnformer. If the Pulse trasnformer and other circuit is OK then thyristor is defective.
If the amplitude of the pulse is more then Gate cathore resistance is weakening.

The above procedure is just to check the device without removing from the equipment.

For Proper Fool Proof method of cheking, Thyristor modules are to be removed separately and can be tested using a simple kit involving a 9v battery, a Filament Bulb(9v) and a toggle switch.
 
B
I always check thyristor by removing and checking by multimeter.

1. Resistance between anode (A) to Cathode (K) should be 13.5 ohm both directions
2. If Anode (A) to Cathode (K) do not show any value, this means good
3. If A to K shows 0.00 it means not good, i.e. blown
4. A to G should show infinity
 
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