Siemens 6SL38503UM114PA0Z, Operating Instructions & Installation Instructions

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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.
● Fiber-optic cables
Replace the fiber-optic cables according to the instructions for laying fiber-optic cables.
● Opto-transmitter / opto-receiver
● Suppressor capacitors
Defective snubber circuit capacitors may only be replaced on inserted thyristor electronics.
WARNING
Electric shock hazard
The snubber circuit capacitors are not equipped with discharge resistors. The energy
stored in the capacitors is discharged via a circuit in the thyristor electronics. This circuit is
interrupted when the thyristor electronics are withdrawn.
Voltages of up to several 1000 V can occur and cause an electric shock. This can result in
death, severe injuries and significant material damage.
● In this case you should treat the capacitors as if they were charged.
● Discharge the snubber circuit capacitors. Short-circuit the snubber circuit capacitors
before you withdraw the thyristor electronics.
Figure 9-7 Thyristor rack position
Maintenance
9.7 Repairs
SINAMICS GL150 6SL38503UM114PA0Z
Operating Instructions Rev.201910301420 MUSTER
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