What it means
A34903 is issued by the Voltage Sensing Module (VSM). The manual states the cause as: An error has occurred when accessing the module-internal I2C bus.
Depending on the drive's configuration, the same condition can also be issued as a fault (F) or as a message with no reaction (N).
Why it appears
- An error occurred when the drive accessed the I2C bus inside the Voltage Sensing Module (VSM).
What to check
- For the drive objects configured as VECTOR, the manual's remedy is to replace the Terminal Module.
- For the remaining drive objects, the manual's remedy is to replace the Voltage Sensing Module (VSM) itself.
Acknowledging and restarting
While A34903 is present as an alarm, no acknowledgement is needed. When the same condition is issued as a fault, it is acknowledged immediately by POWER ON.
The same on every family
Every manual that describes A34903 gives it the same reaction, acknowledgement and message class.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | NONE | NONE | Hardware/software error (1) | Voltage Sensing Module (VSM) | SINAMICS S120, S150 List Manual · p. 3194 |
| G130, G150 | NONE | NONE | Hardware/software error (1) | Voltage Sensing Module (VSM) | SINAMICS G130, G150 List Manual · p. 1864 |
| S120, S150 | NONE | NONE | Hardware/software error (1) | Voltage Sensing Module (VSM) | SINAMICS S120, S150 List Manual · p. 3194 |
| G130, G150 | NONE | NONE | Hardware/software error (1) | Voltage Sensing Module (VSM) | SINAMICS G130, G150 List Manual · p. 1864 |
The drives this code lives on
A34903 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 SINAMICS alarm A34903 mean?
It reports an error that occurred when accessing the module-internal I2C bus of the Voltage Sensing Module (VSM).
How do I clear SINAMICS A34903?
The manual's only remedy is to replace the module named for the drive object: the Voltage Sensing Module (VSM), or the Terminal Module on the VECTOR drive objects.
Does alarm A34903 need an acknowledgement?
Not as an alarm. If the condition is issued as a fault, it is acknowledged immediately by POWER ON.
Can A34903 appear as something other than an alarm?
Yes. Depending on the drive configuration, the same condition can also be issued as a fault (F) or as a message with no reaction (N).
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 A34xxx group · SINAMICS manuals · Siemens manuals