Siemens F72 fault code meaning
Siemens / F72
Series: 6RA28
Single-quadrant rectifier: Thyristor cannot turn off (gate G12
DC drive
Meaning: Four-quadrant rectifier: Thyristor cannot turn off (gate G12 or G22)
Possible causes
Source: 6RA28 Chinese Manual P87
Series: V20
USS/MODBUS setting value
converter
Meaning: No setpoint from USS/MODBUS (on RS485) during the telegram interruption.
Possible causes
Source: SINAMICS V20 Converter P415