What the A.510 alarm means

The servomotor speed exceeded the permitted maximum (about 1.1-1.2 x rated speed); the drive trips to prevent mechanical damage. We have built up many handled cases of this Yaskawa DX100 / DX200 / YRC1000 alarm, and usually the first on-site inspection tells us what is wrong.

Most common causes

  • Motor power wiring U/V/W phase order swapped
  • Encoder wiring error or noise-corrupted encoder signal
  • Position/speed command input too large
  • Wrong command input gain setting
  • SERVOPACK board fault
Field note: Confirm or rule out the first cause first — it is the situation we encounter most.

Step-by-step field fix

  1. Verify the U/V/W phase order at the motor connector — wrong phasing is the classic cause at first servo-on
  2. Inspect encoder cable routing; separate from power cables and check the shield grounding
  3. Review the motion command values and limits in the program
  4. Re-teach or re-limit the affected move and retest at low speed
  5. If the alarm returns at servo-on with correct wiring, replace the SERVOPACK
Safety first: For YASKAWA a-510, this alarm family points at arm motion control: after a reset the arm can move unexpectedly, and anyone inside the working envelope is at strike and pinch risk. The self-serviceable action is Verify the U/V/W phase order at the motor connector — wrong phasing is the classic cause at first servo-on; anything past that falls under the arm working envelope and needs a certified engineer.

How we diagnose motion alarms on site

YASKAWA a-510 belongs to the motion & path family. On YASKAWA a-510 the failing stage is Yaskawa Sigma-series servo drives (servo packs) assigned per axis in the cabinet on the DX100 / DX200 / YRC1000 / YRC1000micro - the gap between command and execution: trajectory planning, joint limits, singularities, following error and mechanical resistance. We start reading YASKAWA a-510 at the pendant alarm list (A / E / 4xxx segments) together with the servo drive's digit display.

The chain involved in YASKAWA a-510 runs: program command -> trajectory planner -> joint targets -> servo execution -> actual position feedback -> deviation compare.

If Motor power wiring U/V/W phase order swapped on YASKAWA a-510 comes with a feeling of drag, the direction is clear: Following error that stays high on one axis only is usually rising mechanical resistance, not a weak servo. We turn the axis by hand with the brake released to feel smoothness, and listen to the reducer for once-per-revolution knocking - a single tick per turn on an RV reducer usually means internal bearing or cycloid damage. Grease that is black, dry or carries metal powder is the plainest evidence. Left alone, this graduates from a motion alarm to a scrapped reducer.

Field notes on this page cover YASKAWA a-510 (Overspeed); written by the Henghuan repair team, updated 2026-10-01.

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Related Motion & Path alarms

4733 — Singular Posture
Same family: this code belongs to the Motion & path alarms family - the page collects all Motion & path-family codes we have handled, with the common inspection order and spares.
Other brands: we also keep field-fix libraries for Universal Robots · Kawasaki · Staubli and more — see the complete alarm code hub.

Frequently asked questions

QWhat does the YASKAWA a-510 alarm mean?

The servomotor speed exceeded the permitted maximum (about 1.1-1.2 x rated speed); the drive trips to prevent mechanical damage. We have built up many handled cases of this Yaskawa DX100 / DX200 / YRC1000 alarm, and usually the first on-site inspection tells us what is wrong. YASKAWA a-510 sits in the motion & path family; on our work orders the highest-frequency trigger for this code is "Motor power wiring U/V/W phase order swapped".

QCan I clear a YASKAWA a-510 alarm myself?

Whether YASKAWA a-510 clears on its own depends on the outcome of "Verify the U/V/W phase order at the motor connector — wrong phasing is the classic cause at first servo-on". Finish the flow with "If the alarm returns at servo-on with correct wiring, replace the SERVOPACK" to confirm YASKAWA a-510 - do not skip it. If that step is clean, the second most frequent cause on YASKAWA a-510 is "Encoder wiring error or noise-corrupted encoder signal". After clearing YASKAWA a-510, watch it for one shift. A second trip means stop and let an engineer arrive with the right test gear for the arm working envelope.

QFor motion alarms like YASKAWA a-510, can you triage remotely first?

The commonest causes we see on YASKAWA a-510 are "Motor power wiring U/V/W phase order swapped, Encoder wiring error or noise-corrupted encoder signal, Position/speed command input too large", so we stock the van against those. For YASKAWA a-510 specifically, we carry mechanical and configuration items: grease, limit switches, drag-chain segments, encoder cables and the parameter sheets for common reducers. For YASKAWA a-510, motion alarms can often be narrowed remotely first, so an on-site visit is not always immediate. Before we roll, tell us what YASKAWA a-510 shows on the pendant alarm list (A / E / 4xxx segments) together with the servo drive's digit display and what the machine was doing - phone or video triage is free.

This page on YASKAWA a-510 is based on the field experience of the Henghuan Robotics repair team. Alarm explanations are our own summary for troubleshooting reference and may differ across controller and software versions — if unsure, verify against Yaskawa documentation or reach out to us. Henghuan is an independent service provider with no affiliation or endorsement by Yaskawa.