3.2 Specifications and Ratings
3.2.6 Allowable Load Moment of Inertia Scaling Factor for SERVOPACKs without Built-in Regenerative Resistors
3
Specifications, Ratings, and Exter
nal Dimensions of SGMMV Servomotors
3-7
3.2.6
Allowable Load Moment of Inertia Scaling Factor for
SERVOPACKs without Built-in Regenerative Resistors
The following graphs show the allowable load moment of inertia scaling factor of the motor
speed for SERVOPACKs
*
without built-in regenerative resistors when an External Regenerative
Resistor is not connected.
If the Servomotor exceeds the allowable load moment of inertia, an overvoltage alarm may
occur in the SERVOPACK.
These graphs provide reference data for deceleration at the rated torque or higher.
*
Applicable SERVOPACK models: SGD7S-R90A, -1R6A, -R90F, and -2R1F
3.2.7
Servomotor Heat Dissipation Conditions
The Servomotor ratings are the continuous allowable values when a heat sink is installed on the
Servomotor. If the Servomotor is mounted on a small device component, the Servomotor tem-
perature may rise considerably because the surface for heat dissipation becomes smaller.
Refer to the following graphs for the relation between the heat sink size and derating rate.
When using Servomotors with derating, change the overload warning and overload alarm
detection timing in advance based on the overload detection level of the motor. Refer to the fol-
lowing section for the overload detection level of the motor.
3.2.4 Servomotor Overload Protection Characteristics
Note: The derating rates are applicable only when the average motor speed is less than or equal to the rated motor
speed. If the average motor speed exceeds the rated motor speed, consult with your Yaskawa representa-
tive.
0
1000
2000
3000
4000
5000
6000
7000
0
35
30
25
20
15
10
5
Allowable load moment of inertia
scaling factor (times)
Motor speed (min
-1
)
SGMMV-A1A, -A2A, -A3A
The actual temperature rise depends on how the heat sink (i.e., the Servomotor mounting sec-
tion) is attached to the installation surface, what material is used for the Servomotor mounting
section, and the motor speed. Always check the Servomotor temperature with the actual equip-
ment.
Important
90
150
120
60
30
0
150
250
200
100
50
0
100
80
60
40
20
100
80
60
40
20
SGMMV-A1
，
-A2
SGMMV-A3
Derating rate (%)
Heat sink size (mm)
Derating rate (%)
Heat sink size (mm)
