Rockwell Automation 1557 MEDIUM VOLTAGE AC DRIVE - Manual (Page 260)

10-18 TROUBLESHOOTING
1557-UM050F-EN-P – June 2013
The gate-cathode voltage during gating of a 3000A GTO
All Voltages have a tolerance
of +/- 1V. +7V
+0.6V
-20V
-22V
GTO GATE
CATHODE
(TB9-2,TB9-3)
-Test point in bold
connects positive lead.
0V
-10V
200uS

20uS
OFF ON
GTO GTO
Actual waveforms at different time bases.