6
1.2.4 Motor heat and noise
The output of the AC drive is pulse width modulation (PWM) wave with certain
harmonic
frequencies, and therefore, the motor temperature, noise, and
vibration are slightly
greater than those when the AC drive runs at power
frequency (50Hz).
1.2.5 Voltage-sensitive device or capacitor on output side of the AC drive
Do not install the capacitor for improving power factor or lightning protection
voltage sensitive resistor on the output side of the AC drive because the output
of the AC drive
is PWM wave. Otherwise, the AC drive may suffer transient
overcurrent or even be
damaged.
1.2.6 Contactor at the I/O terminal of the AC drive
When a contactor is installed between the input side of the AC drive and the
power
supply, the AC drive must not be started or stopped by switching the
contactor on or
off. If the AC drive has to be operated by the contactor, ensure
that the time interval
between switching is at least one hour since frequent
charge and discharge will shorten
the service life of the capacitor inside the
AC drive.
When a contactor is installed between the output side of the AC drive and the
motor,do not turn off the contactor when the AC drive is active. Otherwise,
modules inside theAC drive may be damaged.
1.2.7 When External Voltage is Out of Rated Voltage Range
The AC drive must not be used outside the allowable voltage range specified in
this manual. Otherwise, the AC drive may be damaged . If required, use a
corresponding voltage step-up or step-down device.
Safety and Cautions
