1) RCD ( residual circuit device) fixed beside the VFDs
2) High Leakage Current Warning
Earth connection must be done
3) Motor Insulation Test
When first use, reused after being stored for a long time, do motor insulation test, motor must be disconnected, in order to prevent the poor insulation of motor windings from damaging the AC drive. Install a 500-V mega-Ohm meter, the insulation resistance must not be less than 5 MΩ.
4) Thermal protection of motor
VFD rated power 〉Motor rated power
adjust the motor protection parameters on the operation panel or install thermal relay
5) Running at over 50HZ
AC drive frequency: 0-320HZ
〉300HZ if runs in CLVC( closed loop vector control)/SFVC ( senseless flux vector control)
〉50HZ, consider capacity of machine
6) Vibration of mechanical device
Set the skip frequency when output frequency reaches mechanical resonance point
7) Motor heat and noise
Output voltage is PWM(pulse width modulation) with certain harmonics,
heat, noise and vibration are slightly greater than the power frequency(50HZ).
8) Voltage-sensitive device or capacitor on output side of the AC drive
VFD output voltage is PWM wave, no use capacitor for changing power factors or lightning protection voltage sensitive resistor on AC drive output, it will cause transient over current or damage the AC drive
9) Contactor at the I/O terminal of the AC drive
I terminal: do not use contactors to switch on/off the AC drive, if it should be, intervals can be more than 1 hour. frequent charge/discharge shorten capacitor life which is installed inside the AC drive.
O terminal: do not use contactor when AC drive output has current, or it will damage the modules.
10) When external voltage is out of rated voltage range
AC drive can only be used within rated voltage, otherwise, use a corresponding voltage step up/down device.