What it means
A06905 is the Braking Module internal I2t shutdown alarm. The internal Braking Module outputs it when its I2t value becomes high — exactly when 80% of the maximum switch-on duration of the braking resistor has been reached. The drive raises this condition as an alarm without any automatic response; the G130/G150 and the S120/S150 list manuals describe it with identical wording. The manual also notes that the message is displayed via the BO p3685 and cross-references r3685 (Digital Braking Module: Pre-alarm I2t shutdown).
Why it appears
- The internal Braking Module outputs the alarm because of its high I2t value.
- The reported level: 80% of the maximum switch-on duration of the braking resistor has been reached.
What to check
- Reduce the number of braking operations — this is the remedy the manual gives for the high I2t value.
Parameters the manual names
- r3685 — BO: Digital Braking Module: Pre-alarm I2t shutdown: the signal the manual cross-references for this alarm; read it to see the Braking Module's I2t shutdown pre-alarm.
Acknowledging and restarting
No acknowledgement is required for A06905 — the drive does not demand a reset. Address the reported condition with the remedy above, by reducing the number of braking operations.
The same on every family
Every manual that describes A06905 gives it the same reaction, acknowledgement and message class.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| G130, G150 | NONE | NONE | Braking Module faulted (14) | None | SINAMICS G130, G150 List Manual · p. 1531 |
| S120, S150 | NONE | NONE | Braking Module faulted (14) | None | SINAMICS S120, S150 List Manual · p. 2774 |
The drives this code lives on
A06905 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 A06905 mean?
It is the Braking Module internal I2t shutdown alarm: the internal Braking Module outputs it because 80% of the maximum switch-on duration of the braking resistor has been reached. The G130/G150 and S120/S150 manuals describe it identically.
How do I acknowledge or reset A06905?
No acknowledgement is required. The manual's remedy is to reduce the number of braking operations.
Does A06905 trip the drive?
No automatic response is triggered. The alarm only reports that the braking resistor's 80% switch-on duration level has been reached and needs no acknowledgement.
Which parameters belong to A06905?
The message is also displayed via BO p3685, and the manual cross-references r3685 (Digital Braking Module: Pre-alarm I2t shutdown).
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