Problem Of Charged Device Shell - INVT Goodrive300-21 Series Operation Manual

Goodrive300-21 series dual inverter integrated machine for air compressor
Solution to mal-operation of RCD (on the part of system distribution)
a) Check and confirm the power cable is not immersed in water
b) Check and confirm the cable is not broken or switched over;
c) Check and confirm if secondary grounding occurred to the null line;
d) Check and confirm if power cable terminal is in the air switch or the contactor is poorly contacted
(loose screws);
e) Check the single-phase electric equipment and confirm if the ground line is misused as null line;
f) Inverter power cable and motor cable should not be shielded ones.
Leakage protection of motor autotuning
During motor autotuning, the measurement on differing motor parameters is conducted step by step,
in which the first two steps is to measure the resistance of motor stator/rotor while the inverter will
output square wave to motor stator winding at 4kHz (default carrier frequency), as leakage current
generated by 4kHz carrier frequency against distributed capacitance between motor rotor and stator
during charging/discharging is quite obvious, which may cause mal-operation of RCD. If such
problem occurred, bypass RCD first and restore after parameter autotuning is completed.
D.5. Problem of charged device shell
The problem mainly lies in that the device shell carries detectable voltage which gives anyone who
touches it a feeling of electrical shock, however, when the inverter is powered up without running, the
shell will be uncharged (or the voltage it carries is far lower than human body safety voltage).
Solution:
a) If there is distribution grounding or ground pile on users' site, grounding the shell of inverter cabinet
by power GND or ground pile;
b) If there is no ground connection on site, it is necessary to electrically connect the motor shell to
grounding terminal PE of the inverter and confirm that the jumper in "EMC/J10" of the inverter is
short circuited (refer to chapter 2.1.2 for the position of EMC/J10 jumper).
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Appendix D