If the drive has recently experienced a minor fault that was cleared but not fully reset, the drive may remain in a "Trip" state.
DC Bus / Rectifier Issues
Load Related (High inertia + short decel)
The drive has calculated that the motor current has exceeded the safe limit for a specific amount of time. The electronic thermal overload protection function has triggered a warning.
This is distinct from code A920 (Overload Trip), which actually stops the drive. A910 is a predictive warning telling you that a trip is imminent if the load does not decrease.
In very rare cases, if the cause is a momentary input power dip, the alarm may self-clear after a few power cycles. However, Yaskawa’s technical manuals explicitly state that A910 is a “fault” not an “alarm” – meaning the drive will not attempt to run. For 95% of field cases, the drive requires repair or replacement.
In the world of industrial automation, Yaskawa drives (specifically the GA800, GA700, A1000, and U1000 series) are known for their reliability. However, when an error code appears, it demands immediate attention. Among the various alarms, Error Code A910 stands out as particularly “exclusive” due to its specific cause: it is a hardware-exclusive alarm related to the drive’s charging circuit.
Yaskawa error code A910 is not a death sentence for your drive. However, treating it like a simple loose connection will lead to repeated downtime and unnecessary replacements. The exclusive insights in this guide—from capacitor ripple testing to FFC wiggling and ghost firmware bugs—equip you to diagnose with surgeon-like precision.
Remember the golden rule of A910: The operator is usually a victim, not the culprit. The drive’s control board, power supply, or interconnects are the true sources 80% of the time.
By applying this long-form, exclusive troubleshooting methodology, you will reduce mean-time-to-repair (MTTR) from hours to minutes and extend the service life of your Yaskawa automation assets.
Next Steps:
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In the world of high-precision industrial automation, encountering a fault can bring productivity to a grinding halt. If your Yaskawa Sigma-7 Go to product viewer dialog for this item. or Go to product viewer dialog for this item.
series servo drive is displaying A.910, you are seeing an Overload Warning.
While this isn't a hard "fault" that will immediately trip the drive, it is an urgent alert that the system is operating dangerously close to its thermal or mechanical limits. Ignoring an A.910 warning typically leads to an A.710 (Overload: High Load) or A.720 (Overload: Low Load) fault, which will shut down your motor to prevent permanent damage. What Does the A.910 Error Code Mean?
The A.910 code indicates that the drive's internal algorithms have detected an operation that exceeds the rated overload protection characteristics of the motor. Essentially, the drive is "warning" you that if current conditions continue, the motor or the SERVOPACK will overheat. Common Causes of the A.910 Alarm
Understanding why this warning appears is the first step toward a permanent fix. Common culprits include:
Excessive Mechanical Load: Friction in the bearings, a jammed conveyor, or a misaligned gearbox can force the motor to draw more current than intended.
Aggressive Motion Profiles: Rapid acceleration and deceleration cycles that exceed the motor's duty cycle will trigger this warning.
Wiring Issues: Poor contact or incorrect wiring between the SERVOPACK and the motor or encoder can cause erratic readings or inefficient power delivery.
Incorrect Parameter Settings: The overload warning level is defined by parameter Pn52B. If this is set too low for your specific application, you may get "nuisance" alarms. yaskawa error code a910 exclusive
Ambient Temperature: High temperatures inside the electrical panel (above
) reduce the drive's ability to dissipate heat, leading to premature overload warnings. Step-by-Step Troubleshooting Guide
If you are facing an A.910 error, follow these steps to diagnose and resolve the issue: 1. Inspect the Mechanical System
Before diving into software, check the hardware. Disconnect the motor from the load and rotate the shaft by hand. If you feel resistance or "binding," the problem is mechanical. Lubricate joints, check belt tension, and ensure there are no obstructions in the machinery. 2. Verify Wiring Integrity
Ensure all connections at the U, V, and W terminals are tight. Check the encoder cable for any signs of damage or interference. Poor encoder signals can cause the drive to "hunt" for position, increasing the current draw and triggering an overload. 3. Adjust Operating Conditions
If the mechanical system is clear, look at your cycle times. Try reducing the acceleration/deceleration rates or the total duty cycle. You can use the Yaskawa SigmaWin+ software to monitor the Effective Torque Reference to see exactly how hard the motor is working. 4. Check Parameter Pn52B
By default, the A.910 warning is often set to trigger when the load reaches 20% of the maximum overload capacity. If your application naturally runs "hot" but within safe limits, you may need to increase the value of Pn52B (Overload Warning Level) to a more suitable percentage. 5. Environmental Control
Ensure your control cabinet has proper ventilation. If the drive's internal fan has failed, you will see a FAn alarm or an A.910 warning as the heatsink temperature rises. If the fan is clogged, use compressed air to clean the heatsink fins. When to Replace the Hardware
If you have verified the wiring, parameters, and mechanical load, and the A.910 warning persists even when the motor is disconnected, the Go to product viewer dialog for this item.
itself may have a faulty current detection circuit. In these cases, the internal board may require repair or replacement from an authorized center like Precision Zone. Yaskawa GA700 Manual Fault Codes Explained & Solutions If the drive has recently experienced a minor
In the context of Yaskawa servo drives (such as the Sigma-7, Sigma-5, and Sigma-3 series), error code A.910 is a warning indicating an Overload condition.
This code is distinct from a hard "alarm" (which would stop the motor); instead, it serves as a preemptive alert that the system is approaching the thresholds for more severe overload alarms, specifically A.710 (Instantaneous Maximum Load) or A.720 (Continuous Maximum Load). Root Causes of A.910
The warning is typically triggered when the drive detects the motor is working harder than its rated capacity. Common reasons include:
Mechanical Resistance: Excessive friction or a jam in the connected machinery that forces the motor to draw more current to maintain speed.
Operating Conditions: High-frequency acceleration/deceleration cycles or a load inertia that exceeds the motor’s design limits.
Parameter Settings: The overload warning level (parameter Pn52B) may be set too low for the specific application.
Wiring Issues: Incorrect or loose contact in the servomotor or encoder wiring can lead to inefficient operation and false load readings.
Environmental Factors: High ambient temperatures (exceeding 40–55°C) within the control panel can reduce the drive's thermal overhead. Troubleshooting & Solutions Yaskawa Servo Drive Alarm Codes Guide | PDF - Scribd
The Yaskawa error code A910 (often displayed as A.910) indicates a "Momentary Power Loss" or "Undervoltage during Run" fault on Yaskawa AC drives (e.g., A1000, V1000, J1000, GA500, GA800 series).
If you encounter A910, follow this logical flow to restore operation: DC Bus / Rectifier Issues