YASKAWA A1000 Technical Manual page 19

• 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 times 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.
When attaching an encoder to an explosion-proof motor, make sure the encoder is also explosion-proof. Use an insulating
signal converter to connect the encoder signal lines to the speed feedback option card.
Geared Motor
Make sure that the gear and the lubricant are rated for the desired speed range to avoid gear damage when operating at low
speeds or very high speeds. 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 to operate 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 burn out the starter coils because
the internal centrifugal switch is not activated. The drive is for use with three-phase motors only.
Motor with Brake
Take caution when using the 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, so be sure to install a separate power supply for the motor
brake. Note that motors with built-in brakes tend to generate a fair amount of noise when running at low speeds.
n Notes on Power Transmission Machinery
Installing an AC drive in machinery that was previously connected directly to the power supply will allow the machine to
operate at variable speeds. Continuous operation outside of the rated speeds can wear on lubrication material in gear boxes
and other power transmission parts. Make sure that lubrication is sufficient within the entire speed range to avoid machine
damage. Note that operation above the rated speed can increase the noise generated by the machine.
YASKAWA ELECTRIC TOEP C710616 41B YASKAWA AC Drive - A1000 Quick Start Guide
i.2 General Safety
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