What it means
The HF Damping Module raises A37502 when the damping voltage exceeds the alarm threshold. The voltage that occurred is recorded in r2124, and the current damping voltage can be watched in r5171. If the damping voltage exceeds an inadmissibly high value, the drive outputs the fault F37002. Depending on the drive's configuration, this same condition can also be issued as a fault rather than as an alarm.
Why it appears
- A motor harmonic with a high amplitude has coincided with the resonance frequency of the output filter.
- The current controller excessively excites the resonance of the output filter.
What to check
- Reduce the motor power in the proximity of the fault-generating frequency.
- Check the current controller and, if required, adapt it.
- If required, use another motor.
Reading the message value
- The alarm value is stored in r2124 and must be interpreted as a decimal number: it is the damping voltage in the case of the fault, given in mV.
Parameters the manual names
- r2124 — alarm value: read here as a decimal number to see the damping voltage (in mV) that was present when the alarm came.
- r5171 — CO: HF damping voltage actual value: use it to watch the damping voltage currently present at the HF Damping Module.
Acknowledging and restarting
As an alarm, A37502 requires no acknowledgement and the drive does not execute an automatic shutdown response. If the drive is configured to issue the same condition as a fault instead, the reaction is NONE (OFF1, OFF2, OFF3)
and it must be acknowledged IMMEDIATELY.
The same on every family
Every manual that describes A37502 gives it the same reaction, acknowledgement and message class.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | NONE | NONE | General drive fault (19) | None | SINAMICS S120, S150 List Manual · p. 3268 |
The drives this code lives on
A37502 is described for S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does SINAMICS alarm A37502 mean?
The HF Damping Module has measured a damping voltage above the alarm threshold. The voltage at that moment is stored in r2124 as a decimal value in mV, while r5171 shows the current HF damping voltage.
Why does A37502 occur?
Either a motor harmonic with a high amplitude coincided with the resonance frequency of the output filter, or the current controller excites the resonance of the output filter excessively. If the damping voltage becomes inadmissibly high, the drive outputs fault F37002 instead.
How do I fix alarm A37502?
Reduce the motor power in the proximity of the fault-generating frequency, check the current controller and adapt it if required, or use another motor if required.
Does A37502 have to be acknowledged?
As an alarm, no acknowledgement is required. If the drive is configured to issue the condition as a fault, it must be acknowledged IMMEDIATELY.
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 A37xxx group · SINAMICS manuals · Siemens manuals