ABB DCT880 - Exchanging Thyristors (Sizes T1-T4); Thyristor module installation (T1-T4); Required tools for thyristor exchange

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Exchange thyristors sizes T1 … T4
Installation of thyristor modules in thyristor power controllers size T1 …
T4 (20 A ... 740 A)
All DCT880 size T1 … T4 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
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 thyristor power controller 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 sizes T1 … T4
3ADW000449R0101 DCT880 Service Manual e a