What it means
A07401 reports that the Vdc_max controller has been switched out (disabled) because it could no longer maintain the DC link voltage (r0070) below the limit value (r1242, r1282). The manuals for the G120, G120XA, G130, G150, S120 and S150 describe this message identically. Depending on the drive's configuration, the same condition can also be output with no reaction (N). The message carries no message value.
Why it appears
- The line supply voltage is permanently above the level specified for the power unit.
- The motor is permanently in the regenerative mode because the connected load drives the motor.
What to check
- Check that the input voltage lies within the permissible range — where required, increase the value in p0210.
- Check that the load duty cycle and the load limits are within the permissible limits.
Parameters the manual names
- r0070 — CO: Valve position voltage setpoint before inversion / U_set before inv; in this message it is the DC link voltage the Vdc_max controller tries to hold below the limit value.
- r1242 — Vdc_max controller switch-in level (Vdc_max on_level); one of the two limit values named in the cause.
- r1282 — Vdc_max controller switch-in level (U/f) (Vdc_max on_level); the second limit value named in the cause.
- p0210 — Drive unit line supply voltage (U_connect); the value to increase when the input voltage is outside the permissible range.
Acknowledging and restarting
No acknowledgement is required, and the drive is not shut down by this message, so no reset or restart step is needed. What counts is the remedy above: keep the input voltage within the permissible range (adjusting p0210 where required) and keep the load duty cycle and load limits within their permissible limits, so that the condition which switched the Vdc_max controller out no longer applies.
What differs between the drive families
Straight from the manuals' own fields — A07401 is not described identically everywhere.
| Drive family | Reaction | Acknowledge | Message class | Component | Manual |
|---|---|---|---|---|---|
| S120, S150 | NONE | NONE | Application/technological function faulted (17) | None | SINAMICS S120, S150 List Manual · p. 2798 |
| G130, G150 | NONE | NONE | Application/technological function faulted (17) | None | SINAMICS G130, G150 List Manual · p. 1544 |
| G120 | NONE | NONE | Application/technological function faulted (17) | — | SINAMICS G120 · p. 876 |
| G120XA | NONE | NONE | — | — | SINAMICS G120XA PN converter · p. 1127 |
The drives this code lives on
A07401 is described for G120, G120XA, G130, G150, S120, S150. These are the converters of those families in our catalogue — price on request.
Questions technicians ask
What does alarm A07401 mean on a SINAMICS drive?
It reports that the Vdc_max controller was switched out (disabled) because it could no longer keep the DC link voltage (r0070) below the limit value (r1242, r1282). Depending on the configuration, the condition can also be output with no reaction (N).
Why does A07401 occur?
The manual names two causes: the line supply voltage is permanently higher than specified for the power unit, or the motor is permanently in the regenerative mode because a load is driving the motor.
How do I clear alarm A07401?
No acknowledgement is required. Check that the input voltage is within the permissible range — increasing p0210 if required — and that the load duty cycle and load limits are within the permissible limits.
Which parameters belong to A07401?
r0070 (the DC link voltage signal), r1242 and r1282 (the Vdc_max controller switch-in levels) and p0210 (the drive unit line supply voltage).
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