7.2 Specifications and Ratings
7.2.9 Allowable Load Moment of Inertia
7-14
7.2.9
Allowable Load Moment of Inertia
The allowable load moments of inertia (motor moment of inertia ratios) for the Servomotors are
given in the
7.2.2 Small-Capacity, Coreless Servomotors: Ratings
Medium-Capacity Servomotors, with Cores: Ratings
on page 7-11. The values are determined
by the regenerative energy processing capacity of the SERVOPACK and are also affected by
the drive conditions of the Servomotor. Perform the required Steps for each of the following
cases.
Exceeding the Allowable Load Moment of Inertia
Use one of the following measures to adjust the load moment of inertia to within the allowable
value.
•
Reduce the torque limit.
•
Reduce the deceleration rate.
•
Reduce the maximum motor speed.
If the above steps is not possible, install an external regenerative resistor.
An Overvoltage Alarm (A.400) is likely to occur during deceleration if the load moment of iner-
tia exceeds the allowable load moment of inertia. SERVOPACKs with a built-in regenerative
resistor may generate a Regenerative Overload Alarm (A.320).
Install an External Regenerative Resistor when the built-in regenerative resistor cannot pro-
cess all of the regenerative power.
Refer to the following catalog for the regenerative power (W) that can be processed by the
SERVOPACKs.
AC Servo Drives
Σ
-7 Series (Manual No.: KAEP S800001 23)
Information
