User Manual

Chapter 11 Maintenance and Inspection
11 - 3
11.3 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 high-resistance range mode) for a conduction test on the control circuit. Do not use a
megger or buzzer for that purpose.
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, and then connect terminals R/L1, S/L2, T/L3, U/T1, V/T2, W/T3,
P/+ and PD/+1 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/L1, S/L2, T/L3, U/T1, V/T2, W/T3, P/+
and PD/+1.(Single phase input model is R/L1, S/L2, T/L3, U/T1, V/T2, W/T3, P/+ and PD/+1)
11.4 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.
Motor
R/L1 S/L2 T/L3 U/T1 V/T2 W/T3
PD/+1 P/+
G
IM
Power suppl
y
Do not connect
power supply
cables to the
inverter.
500 VDC megge
r
Be sure to remove the
j
umper for switching the
internal filter function.
Do not connect the inverter
cables to the motor.
DC500V Megger