KUKA KRC4 Error Code 123

KUKA Robot Major DC Bus

Model: KRC4 | Code: 123

Applicable Systems
KR CYBERTECH

Symptoms

Voltage too low. The DC bus voltage in the KPP/KSP drive module is below the minimum required for operation.

Possible Causes

  • Mains voltage too low or voltage sag
  • Mains contactor or breaker opened while robot running
  • DC bus capacitor degradation
  • KPP/KSP power supply module fault

Troubleshooting Steps

  1. Step 1: Check the equipment status and fault indicators to confirm the active fault code
    Fault indicator or HMI displays code 123 as active
  2. Step 2: Verify all electrical connections, wiring harnesses, and connector seating
    All connections secure, no corrosion, loose pins, or damaged wires
  3. Step 3: Check the communication cable continuity and connector seating at both ends
    Cable continuity confirmed, connectors fully seated with locking tabs engaged
  4. Step 4: Verify communication parameters (baud rate, node address, protocol) match network configuration
    All communication parameters match the network setup
  5. Step 5: Inspect cable for EMI interference: check routing away from high-voltage lines and motor cables
    Cable routed away from EMI sources, shielding intact
  6. Step 6: Check terminating resistors at bus endpoints if applicable (e.g., PROFIBUS, CANopen)
    Terminating resistors installed at both bus ends
  7. Step 7: Reset the fault after restoring communication: power-cycle the affected node
    Communication restores and fault clears

How to Reset

To reset: 1) Fix the communication cable or parameter issue. 2) Power-cycle the affected node. 3) Verify communication restores. Caution: Check all nodes on the bus.

Frequently Asked Questions

  • Q: What does fault code 123 mean on the KUKA KRC4?

    Fault 123 indicates a communication fault. The equipment has lost communication with a connected device or network. Check the communication cables, connectors, and network parameters.

  • Q: Can I continue operating the equipment with fault 123 active?

    No. The equipment has detected a fault condition and has taken protective action (typically stopping or derating). Continuing to operate without fixing the root cause may cause further damage. Always investigate and fix the fault before resuming operation.

Related KUKA Fault Codes

Source: KUKA Robot Controller KRC4 Operating Manual, KUKA Roboter GmbH Documentation

Category: Robot