YASKAWA S Series User Manual page 91

Application
5.6.3 Regenerative Resistor Unit
5.6 Precautions
5.6.1 Overhanging Load
5.6.2 Load Inertia JL
5.6.3 Regenerative Resistor Unit
Do not allow the motor to be continuously rotated by the load while the regenerative brake is
being applied.
Example: Te n s i o n control drive
Do not use the motor for lowering objects without a counterweight.
Rated specifications for the regenerative braking capacity of the SERVOPACK is only for brief
periods while the motor is stopped. Contact your Yaskawa representative about applications with
negative load.
The allowable load inertia ,//, calculated for the motor shaft is limited to less than five times of
the motor inertia (Jm). If the load inertia exceeds this value, an overvoltage alarm may occur dur-
ing deceleration. If this occurs, take one of the following actions. Contact our sales representative
for further details.
• Reduce the torque limit.
• Reduce the deceleration rate.
• Reduce the maximum rotation speed.
A regenerative resistor unit is used as an SGDB SERVOPACK peripheral device with 6.0 kW
or higher capacity. Externally connect a Regenerative resistor unit to 6.0 kW or higher capacity
SERVOPACKS because they do not have built-in regenerative resistors.
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