Mitsubishi Electric FR-A840-00380 (15K) User Manual (English)

Questions and Answers:

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Tom GregoryAug 17, 2025
What to do if hunting occurs in Mitsubishi Electric Inverter motor?
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  Calvin ReyesAug 17, 2025
  If hunting (vibration or acoustic noise) occurs in the motor or machine connected to your Mitsubishi Electric Inverter, it might be due to a speed control gain that is too high. Try performing easy gain tuning or setting Pr.820 lower and Pr.821 higher. Alternatively, the torque control gain could be too high. In this case, set Pr.824 Torque control P gain 1 (current loop proportional gain) lower. Finally, incorrect motor wiring can also cause this issue, so ensure that the wiring is correct.
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Maria LeeAug 25, 2025
What to do if Mitsubishi Electric Inverter speed does not accelerate to the command speed?
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  Michelle AliAug 25, 2025
  If the speed of your Mitsubishi Electric Inverter does not accelerate to the command speed, it may be due to a torque shortage or the torque limit is operating. To resolve this, try raising the torque limit or increasing the capacity. Also, ensure that you are using PI control instead of only P (proportional) control.
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Arthur StewartAug 28, 2025
Why does Mitsubishi Electric FR-A840-00380 (15K) Inverter motor speed fluctuate?
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  Logan PalmerAug 28, 2025
  If the motor speed connected to your Mitsubishi Electric Inverter fluctuates, it could be due to several reasons. First, verify that the speed command sent from the controller is correct and implement EMC measures, and set Pr.72 lower. Another possible cause is a torque shortage, in which case you should raise the torque limit. If the speed control gain is not suitable for the machine, resulting in resonance, perform easy gain tuning.
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Brandi ConradSep 1, 2025
Why acceleration/deceleration time different from setting in Mitsubishi Electric Inverter?
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  Crystal IbarraSep 1, 2025
  If the acceleration or deceleration time of your Mitsubishi Electric Inverter is different from the setting, it could be due to a torque shortage, so try raising the torque limit. Alternatively, the load inertia might be too high, therefore set acceleration/deceleration time suitable for the load.
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Benjamin TaylorSep 5, 2025
Why is machine movement unstable with Mitsubishi Electric Inverter?
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  Anna BradleySep 5, 2025
  If the machine movement connected to your Mitsubishi Electric Inverter is unstable, it could be because the speed control gain is not suitable for the machine. Perform easy gain tuning to correct this. It could also be that the response is slow due to the inverter's acceleration/deceleration time setting, so set the optimum acceleration/deceleration time.
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Gloria MackSep 8, 2025
How to fix rotation ripple during low-speed operation in Mitsubishi Electric FR-A840-00380 (15K)?
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  Randall QuinnSep 8, 2025
  If rotation ripple occurs during the low-speed operation of your Mitsubishi Electric Inverter, it might be due to a high carrier frequency affecting the motor rotation. Try setting Pr.72 lower. Another possible cause is that the speed control gain is too low, so try setting Pr.820 higher.