What it means
F34920 is raised by the Voltage Sensing Module (VSM) when the resistance it evaluates at the connected temperature sensor lies outside the permissible range for that sensor type. The fault value stored in r0949 tells you whether the resistance was too high or too low. Depending on the drive's configuration, the same condition can also be issued as an alarm (A) or as a message without reaction (N) instead of a fault.
Why it appears
- When evaluating the temperature sensor, the VSM detected a resistance value outside the permissible range. The manuals describe this identically for all listed drive objects, so there is one cause.
What to check
- Make sure that the temperature sensor is connected correctly.
- Replace the sensor.
- Allow the unit to cool down, then check the ambient conditions, the load cycle and the cooling (fan fuse).
- Check the temperature sensor type setting (p3665). This step is named in the manual's remedy for the infeed drive objects; the entries for the vector drive objects do not list it.
- Infeed: check the line filter type setting (p0220). Like the previous step, this belongs to the infeed remedy only.
Reading the message value
The drive writes the fault value into r0949; interpret it as a decimal number:
- 1 — overtemperature, wire breakage or sensor not connected. KTY: R > 1630 Ohm, PT1000: R > 1720 Ohm.
- 2 — measured resistance too low. PTC: R < 20 Ohm, KTY: R < 50 Ohm, PT1000: R < 723 Ohm.
Parameters the manual names
- r0949 — holds the fault value of this message; read it as a decimal number to distinguish overtemperature or wire breakage (1) from a resistance that is too low (2).
- p3665 — the sensor type setting of the VSM temperature evaluation; check that it matches the temperature sensor actually connected.
- p0220 — for an infeed, check the line filter type setting here as part of the remedy.
Acknowledging and restarting
F34920 carries no automatic shutdown reaction. Acknowledge the fault immediately; a POWER ON also clears it. Where the drive's configuration issues the condition only as an alarm or as a message without reaction, neither a reaction nor an acknowledgement applies.
What differs between the drive families
Straight from the manuals' own fields — F34920 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | NONE (OFF1, OFF2) | IMMEDIATELY (POWER ON) | External measured value / signal state outside the permissible range (16) | Voltage Sensing Module (VSM) | SINAMICS S120, S150 List Manual · p. 3195 |
| G130, G150 | NONE (OFF1, OFF2) | IMMEDIATELY (POWER ON) | External measured value / signal state outside the permissible range (16) | Voltage Sensing Module (VSM) | SINAMICS G130, G150 List Manual · p. 1865 |
| S120, S150 | NONE | IMMEDIATELY (POWER ON) | External measured value / signal state outside the permissible range (16) | Voltage Sensing Module (VSM) | SINAMICS S120, S150 List Manual · p. 3196 |
| G130, G150 | NONE | IMMEDIATELY (POWER ON) | External measured value / signal state outside the permissible range (16) | Voltage Sensing Module (VSM) | SINAMICS G130, G150 List Manual · p. 1865 |
The drives this code lives on
F34920 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 value 1 in r0949 mean for F34920?
It means overtemperature, wire breakage or a sensor that is not connected: a KTY sensor then reads above 1630 Ohm and a PT1000 above 1720 Ohm.
What does fault value 2 of F34920 mean?
The measured resistance is too low: below 20 Ohm for a PTC, below 50 Ohm for a KTY and below 723 Ohm for a PT1000.
How is F34920 cleared?
Acknowledge the fault immediately after fixing the cause; a POWER ON also clears it. If the drive is configured to issue the condition only as an alarm or a no-reaction message, no acknowledgement is required.
Which parameter sets the temperature sensor type for the VSM?
p3665 — check that it matches the sensor actually connected. For an infeed, the remedy additionally says to check the line filter type setting in p0220.
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