What the Er.234 alarm means
The drive detected the motor accelerating without a matching command — a runaway condition — and shut down immediately. This is one of the faults our repair team handles on INOVANCE IRCB500 / IRCB501 + SV660 servo systems — the cause is usually identifiable within the first on-site inspection.
Most common causes
- Motor power phases U/V/W wired in the wrong order
- Encoder signal wrong or disconnected
- Wrong encoder resolution or motor model parameter
- Drive control board fault
Step-by-step field fix
- Check the U/V/W phase order first — wrong phasing is the classic cause after cable replacement
- Verify the encoder connector is fully seated
- Confirm the motor model and encoder parameters match the nameplate
- Test at minimum speed after correction
- Replace the drive if wiring and parameters are proven correct
Still stuck? Get an engineer on the phone — right now
Tell us the alarm code, the robot model and what was happening when the alarm came up. Our engineers run these diagnostics every day, and remote diagnosis by phone or video call is free.
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Related Motion & Path alarms
Er.630 — Motor Stall (Blocked Rotor)Frequently asked questions
QWhat does the INOVANCE Er.234 alarm mean?
The drive detected the motor accelerating without a matching command — a runaway condition — and shut down immediately. In field practice it belongs to the motion & path family of faults.
QCan I clear a INOVANCE Er.234 alarm myself?
Sometimes. Work through the step-by-step checks on this page — the first listed cause is what we find most often in the field. If the alarm returns after two attempts, or the fault involves power, brakes or safety circuits, stop and call a qualified robot service engineer.
QHow fast can a Henghuan engineer help?
On-site response in the Pearl River Delta within 30 minutes to 3 hours, across mainland China in 1-3 business days, and worldwide within 2-5 business days. Remote diagnosis by phone/WhatsApp/video is available immediately.
Written by the Henghuan Robotics repair team from field service experience. Alarm descriptions are our own summary for troubleshooting reference and may vary by controller and software version — when in doubt, check your INOVANCE documentation or contact us. Henghuan is an independent service provider, not affiliated with or endorsed by INOVANCE.