Yaskawa DR2 Sigma Servo - Manual (Page 258)

SERVO SELECTION AND DATA SHEETS
5.3.6 Overhanging Loads
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2) An overvoltage alarm is likely during deceleration if the load inertia exceeds the range of
the diagrams. Take one of the countermeasures below.
a) Reduce the torque limit value.
b) Reduce the deceleration rate.
c) Reduce the maximum speed used.
d) Add a regenerative unit (applicable to 200V 30W to 200W) or external regenerative
resistor (applicable to 100V 200W, 300W or 200V 400W, 750W).
5.3.6 Overhanging Loads
1) A Servomotor may not be operated under an overhanging load, that is a load which tends
to continually rotate the motor.
Under an overhanging load (e.g. when the direction of the torque applied by the motor is
opposite from the direction of shaft rotation), the Servopack regenerative brake is applied
continuously and the regenerative energy of the load may exceed the allowable range
and damage the Servopack.
The regenerative brake capacity of the DR2 Servopack is rated for short-time operation,
approximately equivalent to the deceleration stopping time.
• Overhanging Load Example 1: Motor drive for vertical axis, using no counterweight
Motor
• Overhanging Load Example 2: Tension control drive
Tension
Motor subject to be rotated from feed
motor to keep applied tension.
Motor
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