Rockwell Automation 1560E SMC Flex Smart Motor Controller - Manual (Page 131)

Troubleshooting 9-13
5. Complete heatsink assemblies with matched SCRs are available as a
renewal part (see Appendix D). In most cases, the assembly can be
dismantled to replace the SCRs.
SCR Replacement Procedure
Note: This procedure applies to 180A and 360A units < 5000V only.
Important: Refer to OEM documentation for SCR stack location in 1503E.
A. Remove SCR Stack from Unit
For all types of SMCs, the stack requiring new SCRs must first be removed
from the unit as follows:
1. Remove all power from the equipment.
To avoid shock hazard, ensure main power has been
disconnected before working on the controller, motor or
control devices. Verify that all circuits are voltage free
using a hot stick or appropriate voltage measuring
device. Failure to do so may result in burns, injury or
death.
2. Service to phase A module may require removing the medium voltage
door and swinging out the low voltage panel (for 36-inch wide, two-high
cabinet only); see the low voltage panel, Fig. 9.4.
3. Unplug all fibre-optic cables from the gate-driver board. Unplug gate
lead connectors and thermistor connectors. Remove leads from the left
side of the circuit board.
The grey fibre-optic cables can be damaged if struck or
bent sharply. They have a locking feature which requires
pinching the tab on the connector and gently pulling
straight out. The component on the printed circuit board
should be held to prevent damage.
4. Remove gate-driver board by compressing the locking tabs of the
nylon circuit board supports and carefully pulling the board off the
supports.
5. Disconnect the power cables from the terminals on the left side of the
heatsink assembly. Use care not to damage components. The sharing
resistors are fragile.
A T T E N T I O N A T T E N T I O N
S H O C K H A Z A R D S H O C K H A Z A R D