CHINT NVF5 Series User Instructions page 8

NVF5 Series User Manual
Lubrication of
mechanical
devices
Negative torque
load
Mechanical
resonance point
of load
Occasion of
frequently start
and stop
Motor insulation
check before
connection to
inverter
Capacitor or
voltage
dependent
component for
improving power
factors
Contactor and
switching devices
installed on the
output of the
inverter
Outside rated
voltage
Lightening surge
protection
Altitude and
speed range of motor bearings and mechanical devices must be
ensured, please inquiry in advance if having questions.
The gearbox, gears and other mechanical devices needing
lubrication probably be damaged when running at a low speed for a
long term , please inquiry in advance if having questions.
For lift load , negative torque is often generated, the inverter may
trip due to overcurrent or overvoltage, and then a appropriate brake
assembly should be selected.
Within the output frequency range, the inverter may encounter the
mechanical resonance point of the load, now the skip frequency
shold be selected.
Selecting DI terminals to control the start/stop of the inverter. It is
prohibited to use contactors and other switching devices at the input
side of the inverter for direct and frequent start/stop in case of
equipment damage.
When the motor is used for the first time or before the motor is used
again after being placed for a long time, insulation check shall be
conducted to prevent the effectiveness of insulation of a motor
winding in case of the damage to the inverter. Wiring is shown in the
following figure. In the testing process, it is supposed to adopt a
500V voltage type megger and guarantee that the insulation
resistance is not less than 5MΩ.
Since the inverter PWM output waveform, fault trip of the inverter or
damage to devices may be caused if a capacitor or an anti-thunder
piezoresistor installed at the inverter output must be removed.
If a contactor and other switching devices will be used between the
output of the inverter and the motor, please ensure that switch
operation is performed on the inverter whitout running; otherwise,
the inverter may be damaged.
It is not suggested to use the inverter beyond the allowable
operating voltage range, and please use a corresponding voltage
increasing/decreasing device for voltage transformation if needed.
A surge protection device installed in the inverter.The inverter has
certain self-protection ability to inductive thunder.
In the areas at the altitude exceeding 1000 meters, The inverter can
Chapter 1 Safety Information
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