Yaskawa Z1000U - Manual (Page 20)

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. Selecting Closed Loop Vector control 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.
• Mechanical resonance can occur with long motor shafts and in applications such as turbines, blowers, and fans with high
inertia loads.
Audible Noise
The audible noise of the motor varies based on the carrier frequency setting. However, drive current derating may be required.
When using a high carrier frequency, audible noise from the motor is comparable to the motor noise generated when running
from line power.
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, 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.
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 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.
i.2 General Safety
20 YASKAWA ELECTRIC TOEP C710636 10B Z1000U HVAC MATRIX Drive User Manual