YASKAWA SGM7J-A5A, Technical Supplement

Page: 213 / 622

Direct Drive Servo Motors
SGM7F (With Core, Inner Rotor)
195
Direct Drive Servo Motors
Allowable Load Moment of Inertia
The allowable load moment s of inertia (motor moment of inertia ratio s ) for the Servomotor s are given in the
Rating s (page 192). The value s are determined by the regenerative energy proce ss ing capacity of the
SERVOPACK and are al s o affected by the drive condition s of the Servomotor. Perform the required Step s for
each of the following ca s e s .
U s e the Si AC Servo Drive Capacity Selection Program to check the driving condition s . Contact
your Ya s kawa repre s entative for information on thi s program.

Excee d ing the Allowa b le Loa d Moment of Inertia
U s e one of the following mea s ure s to adju s t the load moment of inertia to within the allowable value.
•
Reduce the torque limit.
•
Reduce the deceleration rate.
•
Reduce the maximum motor s peed.
If the above s tep s i s not po ss ible, in s tall an external regenerative re s i s tor.

S ERVOPACKs without Built-in Regenerative Resistors
The following graph s how s the allowable load moment of inertia s caling factor of the motor s peed (reference
value s for deceleration operation at or above the rated torque). Application i s po ss ible without an external
regenerative re s i s tor within the allowable value. However, an External Regenerative Re s i s tor i s required in
the s haded area s of the graph s .
Note: Applicable SERVOPACK model s : SGD7S-2R8A and -2R8F

When an External Regenerative Resistor Is Re q uire d
In s tall the External Regenerative Re s i s tor. Refer to the following s ection for the recommended product s .
External Regenerative Resistors (200 V Mo d els) (page 565)
An Overvoltage Alarm (A.400) i s likely to occur during deceleration if the load moment of iner-
tia exceed s the allowable load moment of inertia. SERVOPACK s with a built-in regenerative
re s i s tor may generate a Regenerative Overload Alarm (A.320). Refer to External Regenerative
Re s i s tor s (200 V Model s ) (page 565) for the regenerative power (W) that can be proce ss ed by
the SERVOPACK s .
In s tall an External Regenerative Re s i s tor when the built-in regenerative re s i s tor cannot pro-
ce ss all of the regenerative power.
Information
0
5
10
15
20
25
30
0 100 200 300 400 500 600 700 0 100 200 300 400 500 600 700 0 100 200 300 400 500 600 700
SGM7F-04B
0
2
4
6
8
10
12
14
16
SGM7F-08C
0
5
10
15
20
25
30
35
40
45
SGM7F-10B
Motor speed (min
-1
)
Allowable load moment of inertia
scaling factor (times)
Allowable load moment of inertia
scaling factor (times)
Allowable load moment of inertia
scaling factor (times)
Allowable load moment of inertia
scaling factor (times)
Motor speed (min
-1
)
Allowable load moment of inertia
scaling factor (times)
Motor speed (min
-1
)
Allowable load moment of inertia
scaling factor (times)
0
5
10
15
20
25
30
0 100 200 300 400 500 600 700 0 100 200 300 400 500 600 700
SGM7F-02A
0
5
10
15
20
25
30
35
40
SGM7F-05A
0 100 200 300 400 500 600 700
0
5
10
15
20
25
30
35
40
SGM7F-07A
Motor speed (min
-1
) Motor speed (min
-1
) Motor speed (min
-1
)