Yaskawa J1000 Compact Vector Control Drive - Manual (Page 22)

u Notes on Motor Operation
n Using a Standard Motor
Low Speed Range
The cooling fan of a standard motor is usually designed to sufficiently cool the motor at the
rated speed. As the self-cooling capability of such a motor reduces with the speed, applying
full torque at low speed will possibly damage the motor. To prevent motor damage from
overheat, reduce the load torque as the motor slows. Figure i.4 shows the allowable load
characteristics for a Yaskawa standard motor. A motor designed specifically for operation
with a drive should be used when 100% continuous torque is needed at low speeds.
50
3 6 60
60
70
80
90
100
25% ED (or 15 min)
40% ED (or 20 min)
60% ED (or 40 min)
Frequency (Hz)
Continuous operation
Torque
(%)
20
Figure i.4 Allowable Load Characteristics for a Yaskawa Motor
Insulation Tolerance
Consider motor voltage tolerance levels and motor insulation in applications with an input
voltage of over 440 V or particularly long wiring distances. Contact Yaskawa or your Yaskawa
agent for consultation.
High Speed Operation
Problems may occur with the motor bearings and dynamic balance of the machine when
operating a motor beyond its rated speed. Contact the motor or machine manufacturer.
i.3 Application Precautions
22 YASKAWA ELECTRIC TOEP C710606 47C YASKAWA AC Drive – V1000 Quick Start Guide