F07404 — Drive: DC link voltage monitoring Vdc_max

F07404 is the drive's DC link overvoltage monitoring: it reports that the DC link voltage rose to the upper threshold while that monitoring was enabled, or — in U/f control — that the Vdc_max monitoring built on p1284 responded. The manuals title the code either "Drive: Upper DC link voltage threshold reached" or "Drive: DC link voltage monitoring Vdc_max"; both describe the same condition. On the G120XA the code also fires when kinetic buffering ends and the line supply has not come back in time.

The fault trips the drive, and it must be acknowledged before the drive will start again.

• The DC link voltage monitoring is enabled (p1240, p1280 = 4 or 6) and the DC link voltage climbs to the upper threshold (r1242, r1282) while the drive is in the "Operation" state — printed for the G130, the G150 and for S120/S150 with the vector drive objects.
• On S120/S150 with the servo drive objects the same monitoring (p1240 = 4 or 6) reacts when the upper DC link voltage threshold p1244 is reached in the "Operation" state.
• In U/f control, the Vdc_max monitoring configured in p1284 responded — this is the only cause the manual prints for the G120.
• For S120/S150 vector entries, the DC link voltage control is available because the technology controller is activated, and the supply voltage (p0210, p0212) has been reduced.
• G120XA, kinetic buffering: while buffering was running, the speed dropped below the minimum speed (p1257, or p1297 for vector drives with U/f control) and the line supply stayed away.
• G120XA, kinetic buffering: the maximum buffer time (p1255, and p1295 for vector drives with U/f control) ran out before the line supply came back.

1. Check the line supply voltage — every manual that describes this code starts its remedy here.
2. Check the infeed. The G120 and G120XA remedies name the braking module; the S120/S150 servo remedy says to check the infeed unit or the Braking Module.
3. Adapt the setting for the device line supply voltage, p0210. For S120/S150 with the vector drive objects the remedy additionally sets p0212.0 = 0.
4. On S120/S150 with the servo drive objects, increase the upper DC link voltage threshold (p1244).
5. Where the monitoring is not needed, switch it off: p1240 = 0, on the G130, G150 and S120/S150 vector entries together with p1280 = 0.
6. In U/f control, adapt the Vdc_max monitoring (p1284) — the closing step for G120, G120XA, G130/G150 and S120/S150 vector.

• p0210 — the drive unit's line supply voltage setting; every remedy adapts it to the voltage actually present.
• p0212 — power unit configuration; in the S120/S150 vector remedy, bit 0 is set to 0 (p0212.0 = 0) while adapting the supply voltage.
• p1240 — configuration of the Vdc monitoring: 4 or 6 have it active for this fault, 0 deactivates it.
• p1280 — the U/f counterpart of p1240; on G130/G150 and S120/S150 vector entries it is switched off together with p1240.
• p1244 — upper DC link voltage threshold in the S120/S150 servo entries; the remedy raises it.
• p1284 — time threshold of the Vdc_max monitoring in U/f control; its response is a cause in the G120, G120XA, G130/G150 and S120/S150 vector entries and it is adapted in their remedies.
• p1257 — speed threshold of the Vdc_min controller, named in the G120XA cause when the speed falls below it during kinetic buffering.
• p1297 — the U/f variant of that speed threshold, named for vector drives with U/f control.
• p1255 — time threshold of the Vdc_min controller, i.e. the maximum buffer time in the G120XA cause.
• p1295 — U/f variant of that buffer time for vector drives with U/f control.
• r1242 — the upper threshold level (Vdc_max switch-in level) whose being reached in the "Operation" state raises the code in the vector entries.
• r1282 — the U/f counterpart of r1242.

Once the cause is removed, acknowledge the fault at the operator panel or in the commissioning tool; the drive starts again only after that acknowledgment.