F30074 fault in Siemens V70 Drive indicates a Communication error between the Control Unit and Power Module. This means the data link between the drive’s logic board and its power stages is broken, possibly because the module was improperly seated or removed during operation.
Cause:
Communications between the Control Unit (CU) and Power Unit (PU) via the interface no longer possible. The CU may have been withdrawn or is incorrectly inserted.
Fault value (r0949, interpret hexadecimal):
- 0 hex: a Control Unit with external 24 V supply was withdrawn from the Power Unit during operation; or with the Power Unit switched off, the external 24 V supply for the Control unit was interrupted for some time.
- 1 hex: The Control Unit was withdrawn from the Power Unit during operation, although the encoderless safe motion monitoring functions are enabled (not supported).
- 20A hex: The Control Unit was inserted on a Power Unit, which has another code number.
- 20B hex: The Control Unit was inserted on a Power Unit, which although it has the same code number, has a different serial number.
- 601 hex: The Control Unit was inserted on a Power Unit, whose power/performance class (chassis unit) is not supported.
Remedy:
Reinsert the Control Unit (CU) or the Control Unit adapter (CUAxx) onto the original Power Unit (PU) and continue operation. If required, carry out a POWER ON for the CU and/or the CUA.
