Siemens F71 fault code meaning
Siemens / F71
Series: 6RA28
Single-quadrant rectifier: Thyristor cannot turn off (gate G11
DC drive
Meaning: Four-quadrant rectifier: Thyristor cannot turn off (gate G11 or G21)
Possible causes
Source: 6RA28 Chinese Manual P87
Series: V20
USS setpoint fault
converter
Meaning: (On RS232) No setpoint from USS (on RS232) during the telegram interruption.
Possible causes
Source: SINAMICS V20 Converter P414