● 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interrupted when the thyristor electronics are withdrawn.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 9-3
Thyristor rack position
9.6.4.2
Replacing thyristor electronics
DANGER
Danger when not complying with the five safety rules
Non-observance of the five safety rules can cause death or serious injury. Serious material
damage can also result.
● Observe the five safety rules.
● Work must only be performed on adequately grounded power circuitry.
Maintenance
9.6 Repairs
SINAMICS SL150 6SL38655UM427AA02
Operating Instructions Rev.201910281507 EXAMPLE
77
