3-8
Caution
Do not install two or more different cables or control wires in one pipe or
duct.
(4) Limit the fluctuations of the supply voltage within ±10% of the rated voltage, and also limit the
fluctuations of the frequency between –5% and +3% of the rated value. Although you can run the
pump in these ranges, avoid continuous operation if the voltage is not within ±5% of the rated
value or if the frequency is not within ±2% of the rated value.
Even if the power fluctuations fall within the allowable ranges, the pump characteristics, motor
characteristics, and the temperature rise of the motor may differ from those at the rated voltage
and frequency.
(5) Precautions for using the inverter drive
• Ensure that the electric current during operation does not exceed 90% of the rated value.
• Ensure that the minimum frequency is set to 20Hz.
(Contact us if you need to run the drive at 20Hz or lower.)
• Do not use the inverter to drive a motor equipped with a self-protecting device.
• When driving a 400V-class motor, contact your nearest office of Teral. In some cases it might
be necessary to take measures for inverter surge.
• An inverter-driven motor generates a magnetic sound which may be annoying compared with
the drives using commercial power supply.
• Although this magnetic sound does not adversely affect the quality of the motor, some
inverters allow the user to adjust the tone by changing the carrier frequency. However,
changing the frequency may reduce the allowable output of the inverter. Pay particular
attention when selecting the inverter.
• If the pump and motor produce resonance during normal operation, do not run them in the
range of the rotation speed.
Caution
Do not run the pump at a frequency exceeding 60 Hz (50 Hz for models
dedicated to 50Hz). Failure to observe this may overload the motor,
causing it to burnout. If the models dedicated to 60Hz are run at 50Hz, the
performance will deteriorate.
