Delta Electronics ASDA-B2 series User Manual page 32

ASDA-B2
(b) With Load
When there is an external load torque, servo motor is in reverse rotation when external
load greater than motor torque. Servo motor is usually in forward rotation and the motor
torque output direction is the same as the rotation direction. However, there is still
some special condition. If the motor output torque is in the reverse direction of rotation,
the servo motor is also in the reverse direction of rotation. The external power is input
into the servo drive through servo motor. The figure below is an example. The users
can see the motor is in forward rotation at constant speed when a sudden external load
torque change and great power is transmitted to regenerative resistor rapidly.
Reverse
Rotation
External load torque in reverse direction: TL x Wr
For the safety, we strongly recommend the users should select the proper resistance
value according to the load.
For example:
When external load torque is a +70% rated torque and rotation speed reaches
3000r/min, if using 400W servo drive (rated torque: 1.27Nt-m), then the users need to
connect a external regenerative resistor which power is 2 x (0.7 x 1.27) x (3000 x 2 x π/
60) = 560W, 40.
Revision September 2013
info@varitel.com - www.varitel.com - Tel. (54) 11-4243-1171 / Fax: (54) 11-4292-7545
Manuel Baliña 456, Lomas de Zamora (B1832CCJ) Buenos Aires, Argentina.
VARITEL INGENIERIA ELECTRONICA S.A.
Motor Rotation Speed
External Load Torque
Motor Output Torque
Forward
Rotation
Chapter 2 Installation and Storage
Reverse
Forward
Rotation
Rotation
TL : External load torque
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