Motor Application Precautions - YASKAWA L1000A Technical Manual

i.2 General Safety

◆ Motor Application Precautions

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Standard Induction Motors
Insulation Tolerance
NOTICE: Consider motor voltage tolerance levels and motor insulation in applications with an input voltage of over 440 V or particularly
long wiring distances.
NOTICE: Ensure that the motor is suitable for inverter duty and/or the motor service factor is adequate to accommodate the additional
heating with the intended operating conditions. A motor connected to a PWM drive may operate at a higher temperature than a utility-
fed motor and the operating speed range may reduce motor cooling capacity.
High-Speed Operation
NOTICE: Mechanical 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.
Low-Speed Range
The cooling fan of a standard motor should 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. Reduce the load
torque as the motor slows to prevent motor damage from overheat. Use a motor designed specifically for operation with a
drive when 100% continuous torque is needed at low speeds.
Torque Characteristics
Torque characteristics differ compared to operating the motor directly from line power. The user should have a full
understanding of the load torque characteristics for the application.
Vibration and Shock
The drive allows selection of high carrier PWM control and low carrier PWM control. Selecting high carrier PWM can
help reduce motor oscillation.
If resonance occurs, install shock-absorbing rubber around the base of the motor and enable the Jump frequency selection
to prevent continuous operation in the resonant frequency range.
Audible Noise
Noise created during run varies by the carrier frequency setting. When using a high carrier frequency, audible noise from
the motor is comparable to the motor noise generated when running from line power. Operating above the rated r/min,
however, can create unpleasant motor noise.
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Precautions for PM Motors
NOTICE: Damage to Equipment. Improper sequencing of output motor circuits could result in damage to the drive. Do not connect
electromagnetic switches or magnetic contactors to the output motor circuits without proper sequencing. Do not open the main circuit
between the drive and the motor while the PM motor is rotating.
• Contact Yaskawa or your Yaskawa agent if you plan to use any PM motor not endorsed by Yaskawa.
• When using a holding brake, release the brake prior to starting the motor. Failure to set the proper timing can result in
speed loss.
WARNING! Sudden Movement Hazard. Use the Initial Pole Search Status Signal (H2-
brake is not released before the Initial Magnetic Pole Search is completed. Failure to comply may cause inadvertent elevator
movement resulting in serious injury.
This safety message is applicable under these conditions:
• When applying a PM motor, with an external brake sequence, and the PG-F3 option is not being used.
WARNING! Electrical Shock Hazard. The motor must be at a complete stop before performing any maintenance, inspection, or wiring.
• With a PM motor, drive output must be fully interrupted when the power is shut off and the motor is still rotating.
Failure to comply can result in personal injury from electrical shock.
22 YASKAWA ELECTRIC SIEP C710616 38A YASKAWA AC Drive L1000A Technical Manual
= 61) to interlock the brake to ensure the