YASKAWA AC Drive-A1000 Technical Manual page 23

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.
High-Speed Operation
NOTICE: 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.
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. Selecting high carrier PWM can help reduce
motor oscillation.
Take particular caution when adding a variable speed drive to an application running a motor from line power at a constant
speed. 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 motor speed can
create unpleasant motor noise.
n Synchronous Motors
• Contact Yaskawa or a Yaskawa agent when planning to use a synchronous motor not endorsed by Yaskawa.
• Use a standard induction motor when running multiple synchronous motors simultaneously. A single drive does not have
this capability.
• A synchronous motor may rotate slightly in the opposite direction of the Run command at start depending on parameter
settings and rotor position.
• The amount of generated starting torque differs depending on the control mode and motor type. Set up the motor with the
drive after verifying the starting torque, allowable load characteristics, impact load tolerance, and speed control range.
Contact Yaskawa or a Yaskawa agent when planning to use a motor that does not fall within these specifications:
• In Open Loop Vector Control for PM motors, braking torque is less than 125% when running between 20% and 100% speed,
even with a braking resistor. Braking torque drops to less than 50% when running at less than 20% speed.
• In Open Loop Vector Control for PM motors, the allowable load inertia moment is approximately 50× higher than the motor
inertia moment.
Contact Yaskawa or a Yaskawa agent for questions concerning applications with a larger inertia moment.
• When using a holding brake in Open Loop Vector Control for PM motors, release the brake prior to starting the motor.
Failure to set the proper timing can cause speed loss.
• To restart a coasting motor rotating over 200 Hz while in V/f Control, first use the Short Circuit Braking function to bring
the motor to a stop. Short Circuit Braking requires a special braking resistor. Contact Yaskawa or a Yaskawa agent for
details.
• To restart a coasting motor rotating below 200 Hz, use the Speed Search function if the motor cable is not too long. If the
motor cable is relatively long, stop the motor using Short Circuit Braking.
n Specialized Motors
Multi-Pole Motor
The rated current of a multi-pole motor differs from that of a standard motor, so be sure to check the maximum current when
selecting a drive. Always stop the motor before switching between the number of motor poles. The motor will coast to stop if
a regen overvoltage (ov) fault occurs or if overcurrent (oC) protection is triggered.
Submersible Motor
The rated current of a submersible motor is greater than that of a standard motor, so select the drive capacity accordingly. Use
a motor cable large enough to avoid decreasing the maximum torque level from voltage drop caused by a long motor cable.
Explosion-Proof Motor
The motor and the drive must be tested together to be certified as explosion-proof. The drive is not designed for explosion-
proof areas.
YASKAWA ELECTRIC SIEP C710616 31B YASKAWA AC Drive – A1000 Technical Manual
i.2 General Safety
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