Appendix1 Precautions For Use Of The Mm-Gkr Motor (Precautions When Replacing Servo) - Mitsubishi Electric FR-E700EX Instruction Manual

Appendix1 Precautions for use of the MM-GKR motor (Precautions
when replacing servo)
The control method is PM sensorless vector control. Several restrictions are applied because the encoder is not provided
among other reasons.
When using this drive unit and a sensorless PM motor, always check the machine operation in the actual system.
Restrictions
 In positioning operation, the home position is cleared at servo-OFF or power-OFF because no sensor (encoder) is
provided. Always perform the home position return again.
 In a low-speed operation or at a stop, torque ripples or uneven rotation occur. (The operating conditions and parameter
setting affect these.)
 The positioning accuracy is 1.8°, and the speed control range is 1:1000. However, a slight vibration at a stop or uneven
rotation may occur due to torque ripples. In such a case, 1.8° is the average positioning accuracy, and 1:1000 is the
average speed control range.
The maximum wiring length to the motor is 30m. However, to ensure the positioning accuracy of 1.8°, the wiring length
must be within 5m and the power supply voltage must be between 200 and 220V.
 The best response level in the middle-speed range or higher is 100Hz, but the response level is decreased (to about 50Hz)
in the low-speed range (0.1kW: 600r/min or lower or 0.2 to 0.75kW: 300r/min or lower).
 Sensors such as an encoder are not provided. When mechanical protection related to positioning is necessary, install such
protection externally.
 No dynamic brake circuit is built in. Prepare a dynamic brake externally if needed.
 Position deviation or an error may occur due to sudden deceleration of about 0.05 second or lower (3000r/min  0r/min) or
the impact torque exceeding 100% around the zero speed. Check the operation, and adjust the deceleration time, speed
response level, and model adaptive control gain as necessary to prevent position deviation or errors.
Motor structure (compared with the servo motor HG-KR)
 The bracket at the non-load side of MM-GKR13 is larger. (Servo motor: 40, MM-GKR: 43)
 [Reduction gear equipped model] The lengths of the installation bolts are different.
 [Reduction gear equipped model] The shapes of the gear heads are different.
Motor specifications (compared with the servo motor HG-KR)
 The 50W capacity model is not available.
 The continuous rated torque is 90% at 750r/min or lower of MM-GKR13.
 The maximum torque is smaller. (Servo motor: 350%, MM-GKR: 200%)
 The maximum rotation speed is slower. (Servo motor: 6000r/min, MM-GKR: 3000r/min)
 The moment of inertia is different. (For the model without a reduction gear, the moment of inertia is lower by 0 to 16%.
 The recommended load inertia moment ratio (under position control) is lower. (Servo motor: 17 to 26 times or lower, MM-
GKR: 10 times or lower)
 Although no sensor (encoder) is provided, the IP rating and environment conditions are the same.
 Note that problems related to the sensor (encoder) do not occur.
 [Reduction gear equipped model] Reduction gear equipped model has the IP rating of IP44.
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