What it means
A07908 is an alarm titled Internal armature short-circuit active. It tells you that the internal armature short-circuit is selected (p1231 = 4) and that the Motor Module signals the motor is short-circuited through the power semiconductors (r1239.5 = 1). While this state is present, the pulses cannot be enabled. The G130/G150 and S120/S150 manuals describe this alarm identically, so everything on this page applies to both.
Why it appears
- The internal armature short-circuit is selected (p1231 = 4).
- The Motor Module signals that the motor is short-circuited through the power semiconductors (r1239.5 = 1).
- As long as this state is present, the pulses cannot be enabled.
What to check
- Check the selection in p1231: the alarm is issued because the internal armature short-circuit is selected there with the value 4, so confirm this matches the braking function you intend for the connected motor.
- For synchronous motors, activate the armature short-circuit braking with the binector input signal p1230 = 1.
- For the activation and configuration of the function, the manuals refer you to p1230 (Armature short-circuit / DC braking activation, ASC/DC brk act) and p1231 (Armature short-circuit / DC braking configuration, ASC/DCBRK config).
Parameters the manual names
- p1230 (BI: Armature short-circuit / DC braking activation / ASC/DC brk act) — for synchronous motors, set this binector input signal to 1 to activate the armature short-circuit braking.
- p1231 (Armature short-circuit / DC braking configuration / ASC/DCBRK config) — the value 4 selects the internal armature short-circuit; this selection is the condition under which A07908 appears.
Acknowledging and restarting
No acknowledgement is required for this alarm, and the manuals give no separate reset step. The alarm accompanies the active internal armature short-circuit — the selection p1231 = 4 with r1239.5 = 1 — and the only action the manuals describe is activating the armature short-circuit braking for synchronous motors with the signal p1230 = 1.
The same on every family
Every manual that describes A07908 gives it the same reaction, acknowledgement and message class.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | NONE | NONE | Application/technological function faulted (17) | Power Module | SINAMICS S120, S150 List Manual · p. 2880 |
| G130, G150 | NONE | NONE | Application/technological function faulted (17) | Power Module | SINAMICS G130, G150 List Manual · p. 1609 |
The drives this code lives on
A07908 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 A07908 mean?
It reports that the internal armature short-circuit is active: the Motor Module signals the motor is short-circuited through the power semiconductors (r1239.5 = 1) and the pulses cannot be enabled. The internal armature short-circuit is selected with p1231 = 4.
Does A07908 have to be acknowledged?
No. The manuals list no acknowledgement for this alarm and give no separate reset step; it accompanies the active armature short-circuit state.
How do I activate armature short-circuit braking?
For synchronous motors, apply the signal 1 to binector input p1230. The function itself is configured in p1231, where the value 4 selects the internal armature short-circuit.
Is A07908 a fault or an alarm?
A07908 appears as an alarm titled Internal armature short-circuit active, and it is described identically for the G130/G150 and S120/S150 families.
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 A07xxx group · SINAMICS manuals · Siemens manuals