What it means
F34850 means the Voltage Sensing Module (VSM) has detected an internal software error. The manual describes the fault identically for the infeed and vector drive objects: the error lies in the VSM itself, not in the motor or the power cables. The specific error is identified by the fault value that the drive stores in r0949, which must be read as a decimal number. Because the acknowledgement requires a power-on, the drive must be switched off and on again before it will run again.
Why it appears
- An internal software error in the Voltage Sensing Module (VSM) has occurred.
- Which of the two internal errors occurred is recorded as a decimal fault value in r0949.
What to check
- Read the fault value in r0949, interpreting it as a decimal number, to see which internal error the VSM reported.
- If required, upgrade the firmware in the Voltage Sensing Module (VSM).
- Replace the Voltage Sensing Module (VSM).
- If the fault cannot be cleared by these steps, contact Technical Support.
Reading the message value
- The drive stores the fault value in r0949; interpret it as a decimal number.
- 1: Background time slice is blocked.
- 2: Checksum over the code memory is not OK.
Parameters the manual names
- r0949 — read it here as a decimal fault value: 1 means the background time slice is blocked, 2 means the checksum over the code memory is not OK.
Acknowledging and restarting
This fault is acknowledged by switching the drive off and on again (POWER ON). Since the error is inside the VSM software, it may return after restart; in that case a firmware upgrade or replacement of the Voltage Sensing Module is the remedy the manual gives.
What differs between the drive families
Straight from the manuals' own fields — F34850 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | Infeed: OFF1 (NONE, OFF2) Vector: OFF1 (NONE, OFF2, OFF3) | POWER ON | Hardware/software error (1) | Voltage Sensing Module (VSM) | SINAMICS S120, S150 List Manual · p. 3189 |
| G130, G150 | Vector: OFF1 (NONE, OFF2, OFF3) Infeed: OFF1 (NONE, OFF2) | POWER ON | Hardware/software error (1) | Voltage Sensing Module (VSM) | SINAMICS G130, G150 List Manual · p. 1859 |
The drives this code lives on
F34850 is described for G130, G150, S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does fault F34850 on a SINAMICS drive mean?
It means the Voltage Sensing Module (VSM) has detected an internal software error. The fault value in r0949, read as a decimal number, tells you which of two internal errors occurred.
What do the fault values 1 and 2 of F34850 mean?
Value 1 means the background time slice is blocked. Value 2 means the checksum over the code memory is not OK.
How do I clear fault F34850?
Upgrade the VSM firmware if required, replace the Voltage Sensing Module, and contact Technical Support if the fault cannot be cleared. The fault is acknowledged by a POWER ON, so the drive must be switched off and on again.
Codes next to this one
Source
Written from Siemens' own List Manuals and operating instructions; every number, designation and parameter on this page is checked against them before publication.
All SINAMICS codes: fault and alarm codes · the F34xxx group · SINAMICS manuals · Siemens manuals