Applicable Systems
IRC5
Symptoms
DC link overvoltage. The drive unit DC link voltage exceeds the maximum allowed value.
Possible Causes
- Regenerative energy from decelerating robot axes
- Brake chopper resistor not connected or open circuit
- Mains voltage too high
- DC link voltage measurement circuit fault
Troubleshooting Steps
- Step 1: Check the equipment status and fault indicators to confirm the active fault code
Fault indicator or HMI displays code 34400 as active - Step 2: Verify all electrical connections, wiring harnesses, and connector seating
All connections secure, no corrosion, loose pins, or damaged wires - Step 3: Check the communication cable continuity and connector seating at both ends
Cable continuity confirmed, connectors fully seated with locking tabs engaged - Step 4: Verify communication parameters (baud rate, node address, protocol) match network configuration
All communication parameters match the network setup - 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 - Step 6: Check terminating resistors at bus endpoints if applicable (e.g., PROFIBUS, CANopen)
Terminating resistors installed at both bus ends - 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 34400 mean on the ABB IRC5?
Fault 34400 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 34400 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.
Source: ABB IRC5 Controller Operating Manual, ABB Robotics Documentation
Category: Robot