Chapter 4 - Exchange of Thyristors for Sizes C1/C2/C2b
VI A
4 - 2
DCS 500 / DCS 600 Service Manual
Install new thyristor
modules
-
Remove old thermal joint compound (grease) from the heat sink.
Preparation of the heat sink: if the area is clean, spread out the
heat-conducting compound with a rubber spatula or by hand. If
the area is dirty, clean the heat sink surface with tissue paper.
Clean the mounting surfaces with an appropriate solvent (e.g.
ethanol).
-
Apply a thin coat of thermal joint compound to the new module.
Spread the thermal joint compound evenly by moving the mod-
ule forward and backward on the heat sink.
-
Tighten the clamping screws by hand until the screw heads
touch the bottom of the module. Then tighten the screws to 2.5
Nm torque. If the module is mounted using four screws, tighten
the screws crosswise.
-
Tighten the screws to nominal torque (see Table below).
-
Reinstall the busbars; make sure, the correct torque is applied
and reconnect all cables.
Thyristor module
Nominal mounting torques
Size
Type
Electrical
connections
Module to
heat sink
20 mm block
SKKT…..
3 Nm
5 Nm
34 mm block
SKKT…..
5 Nm
5 Nm
34 mm block
TT…..
6 Nm
6 Nm
50 mm block
SKKT…..
9 Nm
5 Nm
50 mm block
TT…..
12 Nm
6 Nm
50 mm block
(single thyrist.)
SKET…..
9 Nm
5 Nm
50 mm block
(single thyrist.)
TZ…..
12 Nm
6 Nm
60 mm block
TT425/TT570
12 Nm
6 Nm
Table 4-1 Nominal mounting torques for thyristor modules
3ADW000093R0601_DCS500B/DCS600_Service Manual_e_f
