Chapter 2  Installation  ASDA-B2 
2-14     Revision May, 2018 
Servo Drive 
(kW) 
Servo Motor 
Rotor Inertia 
J (× 10
-4
kg.m
2
) 
Regenerative 
power from empty 
load 3000r/min to 
stop  
Eo (joule) 
Max. 
regenerative 
power of 
capacitance 
Ec(joule) 
Medium 
Inertia 
3.0 
ECMA-E△1830 
54.95 217.73  28 
ECMA-F△1830 
54.95 217.73  28 
ECMA-E△1835 
54.95 217.73  28 
Medium-high 
Inertia 
1.0 
ECMA-F△1308 
13.6 67.25  18 
2.0 
ECMA-F△1313 
20.0 98.90  21 
2.0 
ECMA-F△1318 
24.9 123.13  21 
3.0 
ECMA-F△1830 
54.95 217.73  28 
High 
Inertia 
0.4 
ECMA-G△1303 
8.17  40.40  8 
0.75 
ECMA-G△1306 
8.41  41.59  14 
1.0 
ECMA-G△1309 
11.18  55.29  18 
Eo = J x wr
2
/182 (joule), Wr : r/min 
Assume that the load inertia is N times to the motor inertia and the motor decelerates 
from 3000r/min to 0, its regenerative energy is (N+1) x Eo. The consumed regenerative 
resistor is (N+1) ×  Eo - Ec joule. If the cycle of back and forth operation is T sec, then 
the power of regenerative resistor it needs is 2× ((N+1) x  Eo - Ec) / T. 
Followings are the calculation procedure: 
Step  Procedure  Calculation and Setting Method 
1 
Set the capacity of regenerative 
resistor to the maximum 
Set P1-53 to the maximum value 
2 
Set T cycle of back and forth 
operation 
Enter by the user 
3  Set the rotational speed wr  Enter by the user or read via P0-02 
4  Set the load/motor inertia ratio N  Enter by the user or read via P0-02 
5 
Calculate the maximum 
regenerative energy Eo 
Eo= J * wr
2
/182 
6 
Set the absorbable regenerative 
energy Ec 
Refer to the above table 
7 
Calculate the needful capacitance 
of regenerative resistor 
2 x ((N+1) x Eo – Ec) / T 
Take 400W as the example, the cycle of back and forth operation is T = 0.4sec, the 
maximum speed is 3000r/min and the load inertia is 7 times to the motor inertia. Then, 
the needful power of regenerative resistor is 2 × ((7+1) × 1.68 – 8) / 0.4 = 27.2 W. If it is 
smaller than the built-in capacity of regenerative resistor, the built-in 60W regenerative