Safety and Precautions   MD280/MD280N User Manual 
When the motor is used for the first time, or when the motor is reused after 
being kept, or when periodical inspection is performed, it shall conduct 
motor insulation inspection so as to avoid damaging the inverter because 
of the insulation fault of the motor windings.  The motor wires must be 
disconnected from the inverter during the insulation inspection. It is 
recommended to use the 500V megameter, and the insulating resistance 
measured shall be at least 5Mȍ.  
1.2.2 Thermal Protection of the Motor 
If the ratings of the motor does not match those of the inverter, especially 
when the rated power of the inverter is higher than the rated power of the 
motor, the relevant motor protection parameters in the in the inverter shall 
be adjusted, or thermal relay shall be mounted to protect the motor.   
1.2.3 Running with Frequency higher than Standard Frequency 
This inverter can provide output frequency of 0Hz to 300Hz. If the user 
needs to run the inverter with frequency of more than 50Hz, please take the 
resistant pressure of the mechanical devices into consideration. 
1.2.4 Vibration of Mechanical Device 
The inverter may encounter the mechanical resonance point at certain 
output frequencies, which can be avoided by setting the skip frequency 
parameters in the inverter.   
1.2.5 Motor Heating and Noise 
Since the output voltage of inverter is PWM wave and contains certain 
harmonics, the temperature rise, noise and vibration of the motor will be 
higher than those when it runs at standard frequency.   
1.2.6 Voltage-sensitive Device or Capacitor Improving Power Factor 
at the Output Side 
Since the inverter output is PWM wave, if the capacitor for improving the 
power factor or voltage-sensitive resistor for lightning protection is mounted 
at the output side, it is easy to cause instantaneous over current in the 
inverter, which may damage the inverter. It is recommended that such 
devices not be used.   
1.2.7 Switching Devices like Contactors Used at the Input and Output 
terminal
 
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