there is a difference between phase currents values ia, ib, & ic due to the currents which coming from current transformers through PRP PROTECTION RELAY PANEL TO DIODE RECTIFIER MODULE WHERE PHASE CURRENT C LESS THAN PHASE CURRENT A & PHASE CURRENT B around 1500-2500 amp. & we changed two of a DIODE RECTIFIER MODULE. then the value of the currents is corrected & the difference is canceled for three days after that it returns. when we check the value with a clamp meter we find drop of the value of phase C Before a DIODE RECTIFIER MODULE. I WANT ANY DATA ABOUT a DIODE RECTIFIER MODULE & THE ISOLATOR BREAKER INSIDE THE MARK V CONTROL CABINET.

 

Arafatco… 3-phase diode rectifiers, if uncontrolled and not fitted with a load inductor, will result in some unbalance of its supply line-
currents.

Unbalance magnitude is very dependent on the degree of source voltage variation, resulting in a significant third harmonic! The harmonic content may increase the RMS value, thus damaging the diodes. What are your generator's Ph-Ph voltages?

I suggest you check Control.Com Archives for Bruce Durdle's comments on a like topic!

Regards, Phil Corso