ABB DCT880, Service Manual

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Exchange thyristors size T5
Installation of thyristor modules in thyristor power controllers size T5
(890 A … 960 A)
All DCS800 size T5 are equipped with thyristor modules. In order to keep the operating temperature of the
semiconductor module low, the joint between the heat sink and the module should have a good heat
conducting ability. The electrical conductivity of the connectors must also be good. For this reason, the
following instructions must be observed with particular care.
Required tools
Special tools or material needed in addition to standard tools for the exchange of thyristor modules:
− Torx screwdrivers:
TX10, TX20, TX25
− Torque spanner:
Mounting torques for the thyristor modules to heat sink and
electrical connections see table Nominal mounting torque for T5
thyristor modules .
− Torque spanner for electrical
connections.
13 Nm (M8)
25 Nm (M10)
50 Nm (M12)
− Screws are metric type; use
appropriate nuts.
− Tissue paper.
− Solvent (e.g. ethanol).
− Thermal joint compound (grease): Type Berulub FZ1 E3
Manufacturer: Carl Bechem GmbH, 58089 Hagen
ABB Service: GHSN 390 011 P 0051
or
− Thermal joint compound:
Type WLPF 20 (10 ml)
ABB Service: GHSN 390 011 P 10
Before the work is started, disconnect the converter completely from the power
supply, then check the voltage free condition and make sure, everything is located in
an electrical and mechanical safe condition!
Find faulty thyristor modules
See Fault Tracing Thyristors of this publication.
Exchange thyristors size T5
3ADW000449R0101 DCT880 Service Manual e a