Yaskawa Error Code A910 Exclusive
The RJ45-style or 14-pin connector between the operator and drive is not gold-plated on standard models. In environments with even trace levels of hydrogen sulfide (paper mills, wastewater treatment), microscopic corrosion increases contact resistance. The drive senses this increased resistance as a "disconnected operator" even though the clip feels tight.
| Step | Action | Expected Result | | :--- | :--- | :--- | | 1 | Monitor U1-07 (DC Bus Voltage) during normal run. | Should be ~1.35x input voltage (e.g., 540-620VDC for 400V class, 270-310VDC for 200V class). | | 2 | Check L2-05 (Undervoltage detection level). Factory default is usually 380VDC (400V class). If set too high, nuisance A910 occurs. | Lower L2-05 by 5-10% only if power supply is truly unstable. | | 3 | Check L2-01 (Momentary Power Loss Ride-Thru Time). Default = 1.0 sec. | Increase to 2.0 seconds if utility sags are common. | | 4 | Measure input voltage while running at 100% load. | Voltage drop should not exceed 10% from no-load to full-load. |
Attempt a controlled release
Use the Yaskawa engineering tool
Check network and bus settings
Inspect safety/interlock devices
Resolve lingering logical locks
Firmware and parameter checks
Log and monitor
Title: Overload Warning (Electronic Thermal O/L) Severity: Warning / Alarm (The drive will typically continue to operate unless parameter settings force a stop, but the fault must be cleared to reset the monitor).