Chapter 7 - Exchange of Thyristors for Size C4
DCS 500 / DCS 600 Service Manual
VI A
7 - 1
Installation of "Disc
Type" thyristor in con-
verters size C4
(2050...5150 A)
All DCS 500 and DCS 600 converters sizes A5/C3/C4 are equipped
with disk type thyristors.
The structure of the "Disc type" semiconductor component is such
that it requires a certain compression force to operate. The preven-
tion of overheating of the component essentially depends on a well
heat dissipation between the semiconductor and the conducted
heat sink. It is thus important that all joints have good thermal and
electrical conduction.
Required Tools
Special tools or material needed in addition to standard tools for the
exchange of thyristor modules:
-
Torque spanner for electrical connections:
13 Nm (M8)
25 Nm (M10)
50 Nm (M12)
-
Screws are metric type; use appropriate nuts.
-
17 mm ring spanner for fuse and busbar connections.
-
24 mm ring spanner for press clamp.
-
Tissue paper / solvent (e.g. ethanol).
-
Thermal joint compound:
type
BECHEM-RHUS SU 2
(grease)
Manufacturer:
Carl Bechem GmbH, 58089 Hagen
ABB Service:
GHSN 390 001 P 0001
-
Disassembly tool:
DCF 1066721 P1
Note:
For more detailed information about the wiring of
the power part, see publication
Technical Data.
Therefore strict observance of the build in instructions given below
is of utmost importance. Make sure that the new component can
replace the old one in accordance with the spare part list (see
Ap-
pendix A).
Thyristors are always mounted in the same direction, independent
of current, voltage, number of quadrants (2-Q or 4-Q) version or left
or right side connection. Semiconductors and heat sinks are to be
handled carefully to avoid scratches and other damage. Avoid
touching the contact surfaces. Do not lift the semiconductor with the
gate wire. Do not lift the semiconductor unit by touching the current
contact surfaces. Do not damage the welding flange or the contact
surface.
Before you start work, disconnect the converter
completly from the power supply then check the
voltage free condition and make sure, everything
is located in an electrically and mechanically safe
condition!
3ADW000093R0601_DCS500B/DCS600_Service Manual_e_f
