4. Reattach the cables. Adhere to the markings. Do not interchange the cables.
5. Re-connect the protective circuit after replacing a contactor. Refer to the circuit diagrams to
help you. You will find these in the section headed "Overview diagram, circuit diagram,
terminal diagram" in the "Power Unit Circuit Manual".
9.7.7
Replacing the current transformer
Removing the current transformer
To remove the current transformer, proceed as follows:
1. Observe the five safety rules.
2. Switch off the power supply for the current transformer.
3. If the cores do not have core end markings, mark the connecting point.
4. Disconnect the 3-pole shielded cables for the measuring signal.
5. Remove the fixing screws from the busbar and transformer.
6. Remove the current transformer from the cabinet.
See also
Installing the current transformer
To install the current transformer, proceed as follows:
1. Carry out the removal steps in reverse order.
2. Screw the screws into the busbars with a tightening torque of 25 Nm.
3. After installing the current transformer, check that it works properly.
9.7.8
Replacing the thyristor electronics and thyristors
9.7.8.1
Check components of the thyristor assembly
In the event of a thyristor assembly failing, establish which component has failed:
● Thyristor (by resistance measurement)
When a thyristor fault message is output, the fault value indicates which thyristor is affected.
Check the thyristor resistance while it is installed.
● Thyristor electronics (by replacement)
Send the replaced thyristor electronic boards to the manufacturer for testing.
Maintenance
9.7 Repairs
SINAMICS GL150 6SL38502UM114PA0Z
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Operating Instructions Rev.201910281441 EXAMPLE
