Rockwell Automation 1560E SMC Flex Smart Motor Controller - Manual (Page 132)

9-14 Troubleshooting
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SCR Replacement Procedure (cont.)
6. Remove two (2) nuts at bottom front of heatsink assembly so the module
can be removed using the pull handle. (Phase C requires angling the
module to clear the front cabinet flange). Position fibre-optic cables
and wiring so they will not be damaged as the module is removed from
the cabinet.
7. Pull module out slowly, and slide onto a platform lift, or lift the module
out of the cabinet.
The heatsink assembly is heavy (approx. 25 kg [55 lb]
or greater). To avoid injury, always use two people to
remove and handle the assembly. Place the heatsink on
a cart to aid in its transport.
8. Place the module on a flat surface (see Fig. 9.7, 9.10 and 9.14). When
tilting the module, ensure that wires are not damaged.
B. Replace SCRs
Note: For 600 A units, it is mandatory that the entire stack be replaced.
The high clamping force requires the factory to tighten the clamp
hardware. See Appendix D, Spare Parts section, for part numbers.
Proceed to step C.
Note: • Refer to Figures 9.5 to 9.16.
• SCR positions are numbered in succession from the top down.
• The SCR cathode is at the end with the wide flange.
The SCRs must be oriented correctly with the cathode
end either up or down, depending on the specific assem-
bly. Note the orientation before removing the SCRs, and
refer to the detail in the appropriate figure in this chapter.
1. Remove the shorting bar. Measure the resistance between adjacent
heatsinks to determine which SCR(s) is (are) shorted. Assemblies with
four or six SCRs must use matched sets. See Figures 9.8 and 9.14 for
the position of the matched sets. If an SCR from each set is shorted, all
of the SCRs in the module must be replaced. A properly functionning
SCR will measure in excess of 100 kilohms from anode to cathode,
and 10-40 ohms from gate to cathode.
Power Circuit
Troubleshooting (cont.)
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A T T E N T I O N A T T E N T I O N