F006: DC-Link Overvoltage

Fault significance

F006 means that the DC-link voltage exceeded the permitted shutdown level. Siemens documentation states that the fault value records the DC-link voltage at the fault occurrence and directs attention to line or DC input voltage. In heavy machinery, however, the operating condition is often just as important as the measured supply.

A trip during rapid deceleration, lowering, unwinding or coupled-axis operation suggests energy is being returned into the DC link faster than the system can absorb or regenerate it. The correct investigation is not simply “replace the inverter”; it is to determine how energy enters and leaves the bus.

System-level questions for F006

A line-fed standalone converter, a drive linked to a braking arrangement and a multi-inverter common DC system can all produce F006 through different paths. Record whether the equipment uses a rectifier/regenerative unit, AFE, braking hardware or peer axes on a common bus. Confirm whether the trip is reproducible only during a particular machine movement.

The uploaded Siemens training material explicitly identifies regenerative operation and common DC-bus systems as MASTERDRIVES configurations. This makes a structured energy-path page more useful than a generic overvoltage definition.

Safe response and service path

Do not repeatedly run an inertial or regenerative machine into the same overvoltage event. Preserve fault values, operating state and parameter context, then evaluate whether the energy-path hardware and control sequence are functioning as designed. A repair request without motion context is incomplete.

Where replacement hardware is restricted or a legacy regenerative topology has become unreliable, modernization assessment may be justified; that decision should follow evidence about the bus and application rather than a single fault-code appearance.

Regeneration and common-bus reasoning

In a motor-driven process with inertia, stopping can turn the motor into an energy source. In a common-DC-bus line, one axis can return energy while another consumes it; if the consuming path is insufficient or the regenerative path is unavailable, bus voltage rises. This system behaviour is especially relevant to MASTERDRIVES applications such as winders, hoists and coordinated lines.

The investigation must capture whether the trip occurs with a particular speed command, descending load, emergency stop, loss of another axis or regenerative-unit status. A DC-link overvoltage that is reproducible only on a motion event is qualitatively different from excessive incoming supply measured while idle.

Repair boundary versus application correction

Some F006 cases are corrected through application settings, deceleration strategy or restoration of the braking/regenerative path; others expose failed hardware or incorrect cabinet-system integration. IndustrialDriveData should not prescribe parameter changes without the machine context because a faster production cycle, safety stop requirement or shared-bus control scheme may constrain what is acceptable.

A commercially useful enquiry therefore includes machine function, event sequence, connected regenerative or braking assemblies, topology and fault value. That record can be routed to commissioning support, hardware diagnosis or modernization rather than an indiscriminate replacement quote.

Evidence needed for a regenerative trip

Overvoltage enquiries must contain motion context: commanded stop time, load inertia or lowering condition, whether the trip happens only in one direction, and whether a rectifier/regenerative unit, brake path or common DC system is present. Without these facts, a board-level answer may be technically irrelevant.

Where F006 becomes recurrent, the record should compare fault occurrence before and after the proposed correction under equivalent operating events. This is necessary because a drive that runs idle or at constant speed has not proven that regenerative energy can be controlled during the critical production cycle.

• Fault value and event timing
• Machine motion/loading description
• Regenerative/braking/common-bus configuration
• Any line-voltage evidence
• Repeat verification under triggering event