Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - Classic Control - Manual (Page 275)

Functional Description 5-21
7000 “B” Frame 7000-UM150I-EN-P – June 2013
Diagnostic
feedback high
Diagnostic
feedback low
Voltage across a thyristor when medium voltage is applied
Diagnostic feedback for a healthy SCR
Diagnostic feedback for a shorted SCR
Diagnostic
feedback high
Diagnostic
feedback low
Voltage across a thyristor when medium voltage is applied
Diagnostic feedback for a healthy SCR
Diagnostic feedback for a shorted SCR
Figure 5.9 – Voltage across a thyristor when MV is applied
Typical SGCT Gating pattern
Healthy Diagnostic Feedback
Gate Cathode shorted or PS problem
1
0
0
0
0
0
LIGHT NO LIGHT
NO LIGHT LIGHT
LIGHT NO LIGHT
LIGHT
NO LIGHT
No gating received
No diagnostic feedback
1
1
1
1
Typical SGCT Gating pattern
Healthy Diagnostic Feedback
Gate Cathode shorted or PS problem
1
0
0
0
0
0
LIGHT NO LIGHT
NO LIGHT LIGHT
LIGHT NO LIGHT
LIGHT
NO LIGHT
No gating received
No diagnostic feedback
1
1
1
1
Figure 5.10 – SGCT diagnostics