Chapter 8 - Changing Diodes and IGCTs in 7/9 MVA Phase Modules
ABB
8-10 (18)
3BHS202077 ZAB E01 Rev. C
ACS 6000 Maintenance Manual
8
By adjusting the spreader tool push up the cooler above the diode
until the diode is free.
Remove the lower clamp diode, the isolator disc and the perforated
busbar.
Figure 8-13
Lower Clamp Diode Removed
9
Prepare the components for reassembly.
Check the contact surfaces of the new diode, the coolers and the
isolator disc for any dirt. If necessary, clean the contact surfaces with
an appropriate solvent (e. g. alcohol). Using a fluff-free cloth wipe the
surfaces paying attention not to scratch the surfaces.
Note: Do not use any grease or any electrical joint compound.
10
Put the isolator disk, the perforated busbar and the new diode on top
of each other (mind the correct order) and center them before
inserting the parts into the stack.
Pay attention to the correct polarity particularly when exchanging
diodes from different suppliers. Always verify the polarity with the
corresponding wiring diagram.
When inserting the components be careful to keep them centered.
Figure 8-14
Inserting the Diode
11
Continue with section
8.4.4 Finishing Steps.
