YASKAWA U1000 Quick Start Manual page 11

• In Open Loop Vector Control for PM motors, the allowable load inertia is approximately 50 times higher than the motor
inertia.
Contact Yaskawa or a Yaskawa agent for questions concerning applications with larger inertia.
• 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.
• Use the Speed Search function to restart a coasting motor rotating over 200 Hz while in V/f Control.
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 regenerative 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 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 a high-
frequency current to flow to the capacitors and can damage the capacitors. 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.
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 out 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 C710636 04D U1000 Industrial MATRIX Drive Quick Start Guide
i.1 Preface
11