ABB DCS880 series, Service Manual

Page: 33 / 128

33
Exchange thyristors sizes H1 … H4
3ADW000488R0101 DCS880 Service manual e a
Install new thyristor modules
1. Ensure that the new thyristor module is of the correct type (see Appendix of this manual).
2. Remove old heat-conducting compound (grease) from the heat sink. Clean the mounting surfaces (heat
sink and thyristor module) with an appropriate solvent (e.g. ethanol) by means of tissue paper. When the
heat sink is clean, spread out the heat-conducting compound with a rubber spatula or by hand.
3. Apply a thin layer of heat-conducting
compound to the new thyristor module.
4. Spread the heat-conducting compound evenly by moving the thyristor module forward and backward on
the heat sink.
5. Tighten all clamping screws by hand until the screw heads touch the bottom of the thyristor module. Then
pre-torque the screws to 2.0 Nm.
Note :
If the thyristor module is mounted by means of four screws, tighten the screws crosswise.
6. Tighten the screws to nominal torque according to table
Nominal mounting torque for thyristor modules
and SDCS-BAB-F0x .
Thyristor modules and SDCS-BAB-F0x Nominal mounting torque
Size (width) Type Electrical connections Thyristor module to heat sink
20 mm block SKKT27, 57, 106 2.6 … 3.4 Nm 4.25 … 5.75 Nm
20 mm block MCC26, 56, 95 2.5 … 4 Nm 2.5 … 4 Nm
34 mm block MCC162, 200 4.5 … 5.5 Nm 2.25 … 2.75 Nm
50 mm block MCC255, 312 11 … 13 Nm 4.5 … 7 Nm
50 mm block TT250 10.8 … 13.2 Nm 4.25 … 5.75 Nm
60 mm block MCC501 10.2 … 13.8 Nm 4.25 … 5.75 Nm
60 mm block MT3 10.8 … 13.2 Nm 5.1 … 6.9 Nm
60 mm block TT425 10.8 … 12.6 Nm 5.1 … 6.9 Nm
- SDCS-BAB-F01 - 2.7 … 3.3 Nm
- SDCS-BAB-F02 1.9 … 2.1 Nm 2.7 … 3.3 Nm
7. Reinstall the current transformer. Make sure, its position and direction is correct.
8. Reinstall the busbars. Make sure, the correct torque is applied according to table
Nominal mounting
torque for for thyristor modules and SDCS-BAB-F0x .
9. Reconnect all gate leads to the thyristor module.
10. Perform an OHM test to make sure the thyristor is ok.
11. Reinstall the SDCS-PIN-H01 board.
12. Reconnect all cables and plugs at the SDCS-PIN-H01:
− X22 temperature sensor.
− X3 … X5 current transformers.
− X15 … X18 gate leads.
− X11 firing pulses for SDCS-BAB-F0x.
− X1, X2, X7 line voltage for SDCS-BAB-F0x.