YASKAWA V1000 Quick Start Manual page 24

i.3 Application Precautions
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.
n 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 (oV) fault occurs or if overcurrent protection (oC) 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 gauge 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
also explosion-proof. 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 AC 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. The drive is for use with 3-phase
motors only.
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.
24 YASKAWA ELECTRIC TOEP C710606 47A YASKAWA AC Drive – V1000 Quick Start Guide