NVF5 Series User Manual         Chapter 1 Safety Information
 
1.3 Precautions for Users 
 
 The inverter must be covered with the cover plate before power on in case of the 
danger of electric shock and explosion! 
 The inverters which have been stored for more than 2 years must been done 
experiment. When energized, the voltage regulator is used to slowly increase the 
voltage in case of the danger of electric shock and explosion
!
 
 During power-on, it is not allowed to touch the terminals by hand in case of the danger 
of electric shock! 
 
It is not permitted to operate the inverter with a damp hand in case of the danger of 
electric shock! 
 After replacing control boar
ds,the inverter will begin running after parameters are 
correctly set in case of the danger of equipment damage! 
 The products is intended for qualified personnel to test during running in case of the 
danger of personal injury or equipment damage!   
 Please don’t change original factory parameters in case of the danger of equipment 
damage
!
 
  Attention
 Please ensure the power phase and rated voltage are consistent with the nameplate of 
the product in case of the danger of equipment damage! 
 
Check connection of the main circuit of the inverter to ensure disappearance of short 
circuit and fastened conenction in case of the danger of equipment damage! 
 It is not permitted to control the inverter start and stop frequently in a power-
on and 
power-off mode in case of the danger of equipment damage! 
Description 
Compared with 
power frequency 
running 
The inverter is a voltage source type machine and the output 
voltage is PWM waves including harmonics. Therefore, the 
temperature rise, noise and vibration of the motor will slightly 
increase compared with power frequency running.   
Constant-torque 
low-speed 
running   
When the inverter drives common AC induction motor to run at a 
low speed for a long term, the output torque maybe reduced due to 
the heat dissipation effect of the motor. If it is required to run at a 
low speed and constant-torque for a long term, a variable frequency 
Electronic thermal 
protection value 
of motor   
When using an adaptive motor, the inverter could perform thermal 
protection on the motor. In case that the motor is not matched with 
the inverter in rated capacity, the protection threshold value must be 
adjusted or other protection must be taken for guaranteeing safe 
Running over 
In case that the motor runs at the frequency over 50Hz, in addition 
to increase of the vibration and noise of the motor, the applied 
- 3 -