YASKAWA A1000 Series Quick Start Manual page 14

i Preface & General Safety
• To restart a coasting motor rotating at over 200 Hz while in the V/f control mode, use the Short Circuit Braking
function to first bring the motor to a stop. Short Circuit Braking requires a special braking resistor. Contact Yaskawa or
your Yaskawa agent for details.
Speed Search can be used to restart a coasting motor rotating slower than 200 Hz. If the motor cable is relatively long,
however, the motor should instead be stopped using Short Circuit Braking, which forces the motor to stop by creating a
short-circuit in the motor windings.
Applications with Specialized Motors
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Applications with Specialized Motors
Multi-Pole Motor
Because the rated current will differ from a standard motor, be sure to check the maximum current when selecting a
drive. Always stop the motor before switching between the number of motor poles. If a regen overvoltage fault occurs or
if overcurrent protection is triggered, the motor will coast to stop.
Submersible Motor
Because motor rated current is greater than a standard motor, select the drive capacity accordingly. Be sure to use a large
enough motor cable to avoid decreasing the maximum torque level on account of voltage drop caused by a long motor
cable.
Explosion-Proof Motor
Both the motor and drive need to be tested together to be certified as explosion-proof. The drive is not designed for
explosion proof areas.
Furthermore, if an encoder is attached to an explosion-proof motor make sure the encoder is explosion-proof too. Use an
insulating signal converter for connecting the encoder signal lines to the drives speed feedback option card.
Geared Motor
To avoid gear damage when operating at low speeds or very high speeds, make sure that both the gear and lubricant are
rated for the desired speed range. Consult with the manufacturer for applications that require operation outside the rated
speed range of the motor or gear box.
Single-Phase Motor
Variable speed drives are not designed for operation with single phase motors. Using capacitors to start the motor causes
excessive current to flow and can damage drive components. A split-phase start or a repulsion start can end up burning
out the starter coils because the internal centrifugal switch is not activated. A1000 is for use with three-phase motors
only.
Uras Vibrator
Uras vibrator is a vibration motor that gets power from centrifugal force by rotating unbalanced weights on both ends of
the shaft. After considering the points below, consult with a your Yaskawa representative to determine the best solution
for the application.
• Uras vibrator should be used within the drive rated frequency.
• Use V/f Control.
• Increase the acceleration time five to fifteen times longer than would normally be used due to the high amount of load
inertia of an Uras vibrator. Increase drive capacity for applications that require an acceleration time of less than 5 s.
• Drive may have trouble starting due to undertorque that results from erratic torque (static friction torque at start).
Motor with Brake
Caution should be taken when using a drive to operate a motor with a built-in holding brake. If the brake is connected to
the output side of the drive, it may not release at start due to low voltage levels. A separate power supply should be
installed for the motor brake. Motors with a built-in brake tend to generate a fair amount of noise when running at low
speeds.
Notes on Power Transmission Parts (belts, chains, gear boxes, ...)
Installing a drive in a machine that was directly connected to the power supply allows to adjust the machine speed.
Continuous operation above or below the rated speed can wear on lubrication material in gear boxes and other power
transmission parts. In order to avoid machine damage make sure lubrication is sufficient within the whole speed range.
Note that operation above the rated speed can increase the noise generated by the machine.
14 YASKAWA ELECTRIC TOEP C710616 21C YASKAWA AC Drive - A1000 Quick Start Guide