5.3 Ground Resistance Test with a Megger
When testing an external circuit with a megger, disconnect all the external circuit cables from the inverter to prevent it from being exposed to the test voltage.
Use a tester (in
Apply the ground resistance test using a megger only to the main circuit of the inverter. Do not carry out the test using a megger for its control circuit.
Use a 500 VDC megger for the ground resistance test.
Before the main circuit test with a megger, remove the jumper for switching the inverter's internal filter function, and then connect terminals R, S, T, U, V, W, P, PD, N, RB, R0, and T0 by wires as shown in the figure below. Subsequently, carry out the test.
After the test using the megger, remove the wires from terminals R, S, T, U, V, W, P, PD, N, RB, R0, and T0, and connect the jumper for switching the inverter's internal filter function at the original position.
Note that only inverter models with a capacity of less than 22 kW have the RB terminal.
Power supply
Do not connect power supply cables to the inverter.
500 VDC megger 
R P P
S
TGround
R0 terminal
T0
Motor
N R U
V
IM
Ground W
terminal
Do not connect the inverter cables to the motor.
Be sure to remove the jumper for switching the internal filter function.
5.4 Withstand Voltage Test
Do not carry out a withstand voltage test for the inverter. The test may damage its internal parts or cause them to deteriorate.
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