Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - Classic Control - Manual (Page 321)

Component Definition and Maintenance 6-31
7000 “B” Frame 7000-UM150I-EN-P – June 2013
The method for replacing the Silicon Controlled Rectifier (SCR) is
almost identical to that of the SGCT. The one exception is that the
SCR and circuit board can be replaced independently of one another.
1. Ensure there is no power to the equipment.
A T T E N T I O N A T T E N T I O N To prevent electrical shock, ensure the main
power has been disconnected before working on
the drive. Verify that all circuits are voltage free
using a hot stick or appropriate voltage-
measuring device. Failure to do so may result in
injury or death.
2. Note the position of the Fiber Optic Cables for reassembly.
3. To Remove the SCR and SCR SPGD Board, it is necessary to
remove the Gate Driver Power Supply connector (from snubber
circuit), the fiber optic cable, and the SCR gate-cathode
connection. Exceeding the minimum bend radius (50 mm/2 in.)
of the fiber optic cables may result in damage.
A T T E N T I O N A T T E N T I O N The fiber optic cables can be damaged if struck
or bent sharply. The minimum bend radius is 50
mm (2 inches). The connector has a locking
feature that requires pinching the tab and gently
pulling straight out. The component on the
printed circuit board should be held to prevent
damage.
4. Remove the load on the clamp head assembly as described under
„Checking Clamping Pressure‟ on page 6-23.
5. Loosen the 2 captive screws with a long Phillips screwdriver
until the circuit board is free. It may be necessary to adjust the
position of the heatsinks to allow free movement of the SCR.
6. Slide the SCR and SCR SPGD Board straight out.
7. While grounded, unplug the Gate-Cathode phoenix connector
from the SCR SPGD Board.
Silicon Controlled Rectifier
and SCR Self-Powered Gate
Driver Board Replacement