What it means
F37950 means that an internal software error has occurred in the HF Damping Module. The drive coasts down (OFF2) and cannot restart until the fault has been acknowledged by switching the power supply off and on again. The fault value stored in r0949 contains information about the fault source; the manual notes that it is only for internal Siemens troubleshooting, so no further user-level decoding is given.
Why it appears
- An internal software error has occurred in the HF Damping Module.
What to check
- Read the fault value in r0949, interpreting it as a decimal number — it identifies the fault source and is meant for internal Siemens troubleshooting, so have it ready when contacting Technical Support.
- If necessary, upgrade the firmware in the HF Damping Module to a later version.
- Contact Technical Support.
Reading the message value
- The drive stores the fault value in r0949; interpret the value as a decimal number.
- The value contains information about the fault source — the manual states it is only for internal Siemens troubleshooting and provides no decoding for the user.
Parameters the manual names
- r0949 — fault value of the drive; for F37950 it holds the fault source information, to be read as a decimal number and quoted to Technical Support.
Acknowledging and restarting
The fault is acknowledged by a POWER ON: the drive's power supply must be switched off and then on again before the drive will restart. If F37950 reappears after this, follow the remedy above — upgrade the firmware in the HF Damping Module to a later version or contact Technical Support.
The same on every family
Every manual that describes F37950 gives it the same reaction, acknowledgement and message class.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | OFF2 | POWER ON | Hardware/software error (1) | None | SINAMICS S120, S150 List Manual · p. 3278 |
The drives this code lives on
F37950 is described for S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does fault F37950 mean on a SINAMICS drive?
It reports that the HF Damping Module has detected an internal software error. The drive coasts down and can only be restarted after the power supply has been switched off and on again.
How do I reset fault F37950?
Acknowledgement requires a POWER ON: switch the drive's power supply off and then on again. If the fault comes back, upgrade the HF Damping Module firmware to a later version or contact Technical Support.
What is stored in the fault value r0949 for F37950?
Information about the fault source, to be interpreted as a decimal number. The manual states it is only for internal Siemens troubleshooting, so pass it on when contacting Technical Support.
Why does F37950 keep recurring?
The manual names only an internal software error as the cause. If the fault returns after a POWER ON, upgrade the firmware in the HF Damping Module to a later version and, if necessary, contact Technical Support.
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 F37xxx group · SINAMICS manuals · Siemens manuals