Chapter 7 - Exchange of Thyristors for Size C4
DCS 500 / DCS 600 Service Manual
VI A
7 - 3
Mounting clamp
Disassembly tool
Front view
View from
the right
View from
the left
Figure 7-1
How to use the disassembly tool (at a left thyristor
stack of a converter)
Install new thyristor
-
Ensure that the new thyristor is of the correct type (see
Appen-
dix A). Keep the semiconductor and its surroundings clean. If
necessary clean them with a piece of tissue paper moistened
with solvent.
Note
: Do not touch the polished surfaces of the thyristor.
-
Clean the polished surfaces of the semiconductor with a piece of
tissue paper moistened with solvent. Dry all surfaces. Spread a
thin
layer of heat conducting paste on both sides of the thyristor,
if necessary use a rubber spatula.
-
Connect the gate leads if possible.
-
Clean all parts with tissue paper moistened with solvent, witch
have had or will have contact with the thyristor or each other
(lower / upper heat sink). Do not clean the surfaces of grease
too thoroughly, because the aluminium surfaces will oxidise in a
few seconds. Dry all surfaces.
-
Push the thyristor until it snaps into its mounting clamp.
Note
: Be sure that the thyristor is installed in the right direction.
Do not pinch or cut the gate leads or any other cable.
-
Turn the thyristor so that the gate leads point in the right direc-
tion.
3ADW000093R0601_DCS500B/DCS600_Service Manual_e_f
