What the 5048 alarm means

The main DC bus voltage is too high — regenerative energy is not being dissipated, so the bus pumps up during deceleration. This is one of the faults our repair team handles on Epson RC90 / RC700 (EPSON RC+) systems — the cause is usually identifiable within the first on-site inspection.

Most common causes

  • Regeneration module/resistor fault
  • Deceleration too aggressive for the load
  • Wrong weight/inertia setting making the drive misjudge regen
  • Main power voltage too high
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. Check the main power voltage
  2. Check the regeneration module and resistor
  3. Specify correct weight/inertia settings
  4. Lower speed/acceleration on the failing move
  5. Check for collision or binding that forces overhauling loads
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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Related Drive & Power Stage alarms

4152 — Relay Welding Error of Main Circuit 4154 — Regeneration Resistor Overtemperature 5040 — Motor Torque Output Failure — High Power State 5049 — Overcurrent of Motor Driver 5054 — Motor Overload (Duty)
Other brands: we also keep field-fix libraries for Nachi · Omron · ESTUN and more — see the complete alarm code hub.

Frequently asked questions

QWhat does the Epson 5048 alarm mean?

The main DC bus voltage is too high — regenerative energy is not being dissipated, so the bus pumps up during deceleration. In field practice it belongs to the drive & power stage family of faults.

QCan I clear a Epson 5048 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 Epson documentation or contact us. Henghuan is an independent service provider, not affiliated with or endorsed by Epson.