What the 1011 alarm means

DC bus voltage fell below the lower limit; the drive cannot hold axis torque and trips out. This is one of the faults our repair team handles on EFORT EC2-S controller + TSINO drives systems — the cause is usually identifiable within the first on-site inspection.

Most common causes

  • Supply voltage low or momentary dip
  • Blown input fuse or missing phase
  • Loose main terminals
  • Inrush resistor damaged by frequent power cycling
Field note: the first item on this list is what we find most often on real machines. Check it before you go deeper.

Step-by-step field fix

  1. Measure supply voltage under load
  2. Check all three phases and fuses
  3. Tighten main terminals and inspect for heat discoloration
  4. Reduce ON/OFF cycling frequency
  5. If the supply is clean, replace the drive
Safety first: never bypass safety circuits or force contactors closed. If the alarm involves E-stop chains, brakes or drive power, and you are not a trained robot technician, contact a professional — wrong moves here can cost you a robot or an injury.

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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Hotline: +86-20-39029800 · WhatsApp: +86-188-1886-2860

Related Drive & Power Stage alarms

1001 — Drive Overcurrent (TSINO Servo) 1010 — Drive DC Bus Overvoltage (TSINO) 1020 — Motor Overload (TSINO)
Other brands: we also keep field-fix libraries for JAKA · AUBO · ROKAE and more — see the complete alarm code hub.

Frequently asked questions

QWhat does the EFORT 1011 alarm mean?

DC bus voltage fell below the lower limit; the drive cannot hold axis torque and trips out. In field practice it belongs to the drive & power stage family of faults.

QCan I clear a EFORT 1011 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 EFORT documentation or contact us. Henghuan is an independent service provider, not affiliated with or endorsed by EFORT.