Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - Classic Control - Manual (Page 318)

6-28 Component Definition and Maintenance
7000-UM150I-EN-P – June 2013 7000 “B” Frame
The Symmetrical Gate Commutated Thyristor (SGCT or device)
with attached circuit board is located within the PowerCage
assembly.
SGCTs must be replaced in matched sets:
• 4160V systems use sets of 2
• 6600V systems use sets of 3
The SGCT and associated control board are a single component.
There will never be a time when the device or the circuit board will
be changed individually. There are 4 LEDs on the SGCT, and the
following table describes their functions:
LED 4 Green
Solid Green indicates that the Power Supply to the Card is
OK
LED 3 Green
Solid Green indicates that the Gate-Cathode resistance is
OK
LED 2 Yellow
LED ON indicates the gate is ON, and Flashes alternately
with LED 4 while gating
LED 1 Red
LED ON indicates the gate is OFF, and Flashes alternately
with LED 3 while gating
Do not adjust outside nut.
SGCT captive screws
Inside nut used for
loosening and applying
load to assembly
Figure 6.22 – Replacing the SGCT
Symmetrical Gate
Commutated Thyristor
Replacement