YASKAWA SGMAH, User Manual

Page: 170 / 488

Sigma II User’s Manual Chapter 5: Parameter Settings and Functions
5-86
Connect the servo amplifier and regenerative resistor unit as shown in the following
diagram.
Note: Adequate cooling must be provided for regenerative resistors because they reach very high
temperatures. Also use heat-resistant, non-flammable wire and make sure that the wiring does not
come into contact with the resistors.
5.6.2 Calculating the Regenerative Power Capacity
Simple Calculation Method
When driving a servomotor normally along the horizontal axis, check the external
regenerative resistor requirements using the calculation method shown below.
Servo Amplifiers with Capacity of 400W or Less
Servo amplifiers with a capacity of 400W or less do not have built-in regenerative
resistors. The energy that can be absorbed by capacitors is shown in the following
table. If the rotational energy in the servo system exceeds these values, then connect
a regenerative resistor externally.
Calculate the rotational energy in the servo system using the following equation:
Where: J = J
M
+ J
L
J
M
:
Servomotor rotor inertia (kg-m
2
)
J
L
:
Motor axis conversion load inertia (kg-m
2
)
N
M
: Rotation speed of the servomotor (rpm)
Voltage
Applicable Servo
Amplifiers
Regenerative Energy
that Can be Processed
(joules)
Comments
100V
SGDH-A3BE 7.8
Value when the input voltage is 100V
AC
SGDH-A5BE to -02BE 15.7
200V
SGDH-A3AE, -A5AE 18.5
Value when the input voltage is 200V
AC
SGDH-01AE to -04AE 37.1
Servo amplifier Regenerative
*The user must provide the regenerative resistor.
B3
B2
B1
resistor unit*
R2
R1
E
S
=
J x (N
M
)
2
182
Joules