F30080 — Power unit: Current increasing too quickly

F30080 is raised by the Power Module when the current in the power unit rises too quickly: The power unit has detected an excessive rate of rise in the overvoltage range. The drive switches off immediately and the motor coasts down. Before the drive can run again, the cause must be removed and the fault acknowledged.

• The closed-loop control is parameterized incorrectly.
• The motor has a short-circuit or a fault to ground (frame).
• In U/f operation, the up ramp is set too low.
• In U/f operation, the rated current of the motor is much greater than that of the power unit.
• On an infeed: high discharge and post-charging currents after a line voltage dip.
• On an infeed: high post-charging currents when motoring with an overloaded motor and a DC link voltage dip.
• On an infeed: short-circuit currents at switch-on because there is no commutating reactor.
• The power cables are not correctly connected.
• The power cables exceed the maximum permissible length.
• The power unit is defective.

Two further causes apply only on a parallel switching device (r0108.15 = 1); the manuals print them for the modular converters, while the G120 and G120XA manuals confine themselves to the causes above:

• A power unit has tripped (switched off) due to a ground fault.
• The closed-loop circulating current control is either too slow or has been set too fast.

1. Check the motor data and, if required, carry out commissioning again.
2. Check the motor circuit configuration (star-delta).
3. In U/f operation, increase the up ramp.
4. In U/f operation, check the assignment of rated currents of motor and power unit.
5. On an infeed: check the line supply quality, reduce the motor load and verify that the line reactor is correctly connected.
6. Check the power cable connections.
7. Check the power cables for short-circuit or ground fault.
8. Check the length of the power cables.
9. Replace the power unit.
10. On a parallel switching device (r0108.15 = 1), additionally check the ground fault monitoring thresholds (p0287) and the setting of the closed-loop circulating current control (p7036, p7037).

The drive stores the fault cause in r0949 as a binary value. Interpret the value bitwise to find the affected phase:

• Bit 0: Phase U
• Bit 1: Phase V
• Bit 2: Phase W

• r0949 — read the fault value here and interpret it bitwise: bit 0 phase U, bit 1 phase V, bit 2 phase W.
• r0108 — bit 15 shows whether the converter is a parallel switching device; only then do the additional ground-fault and circulating-current causes and checks apply.
• p0287 — ground fault monitoring threshold; check this setting when a power unit in a parallel switching device has tripped due to a ground fault.
• p7036 — proportional gain of the closed-loop circulating current control; check it on a parallel switching device whose control reacts too slowly or too quickly.
• p7037 — integral time of the closed-loop circulating current control; check it together with p7036 on a parallel switching device.

The power unit switches off immediately and the motor coasts down. Remove the cause first, then acknowledge the fault immediately — the drive will not start again until F30080 has been acknowledged.