What it means
A06351 is output by the infeed when the actual line frequency f_line that it measures is lower than the parameterized alarm threshold: f_line < p0211 * p0285. Depending on how the drive is configured, the same condition can also be signalled as a fault instead of an alarm. The line frequency the infeed determined is stored as the alarm value in r2124 and is shown in the message value.
Why it appears
- The actual line frequency f_line is lower than the parameterized alarm threshold: f_line < p0211 * p0285.
- The alarm can be output in two operating states. During the switch-on phase of the infeed unit, synchronization of the infeed to the line supply is interrupted and is restarted; the alarm is reissued if the line frequency remains less than the parameterized alarm threshold.
- While the infeed is operational, the infeed remains in the "operating" (run) state and alarm A06351 is output — the manual calls this a
critical operational fault
.
What to check
- Check the parameterized line frequency and change it if required (p0211).
- Check the alarm threshold (p0285).
- Check the line supply.
- Check the line supply quality.
Reading the message value
- The message value carries the measured frequency: the drive enters the actual line frequency it has determined, as a floating point value, into the alarm value r2124 (the manual prints the value as "Line frequency: %1").
Parameters the manual names
- p0211 — the parameterized line frequency: it forms the alarm threshold together with p0285 (f_line < p0211 * p0285); check it and change it if it does not match the actual line supply.
- p0285 — line supply frequency undershot alarm threshold: the threshold the measured line frequency is compared against; check its setting.
- r2124 — alarm value: contains the actual line frequency determined (floating point); read it to see the frequency the infeed measured.
Acknowledging and restarting
As an alarm, A06351 leaves the infeed in operation. During the switch-on phase of the infeed unit, synchronization to the line supply is interrupted and is restarted; the alarm is reissued as long as the line frequency remains less than the parameterized threshold. While the infeed is operational, it remains in the "operating" (run) state. If the drive is configured to signal the condition as a fault instead, that fault must be acknowledged — immediately or via POWER ON — before the drive will start again.
The same on every family
Every manual that describes A06351 gives it the same reaction, acknowledgement and message class.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | — | — | Network fault (2) | None | SINAMICS S120, S150 List Manual · p. 2766 |
The drives this code lives on
A06351 is described for S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does alarm A06351 mean on a SINAMICS infeed?
The infeed has measured a line frequency that is lower than the parameterized alarm threshold, f_line < p0211 * p0285. The measured value is stored in r2124.
How do I fix alarm A06351?
Check the parameterized line frequency (p0211) and the alarm threshold (p0285), then check the line supply and the line supply quality.
Why does A06351 appear during switch-on?
During the switch-on phase of the infeed unit the low line frequency interrupts synchronization to the line supply; the infeed restarts synchronization and reissues the alarm if the frequency remains below the threshold.
Can A06351 also be output as a fault?
Yes — depending on the drive's configuration the same condition can be signalled as a fault; the fault must then be acknowledged, immediately or via POWER ON, before the drive starts 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 A06xxx group · SINAMICS manuals · Siemens manuals