Insulation Resistance Test Using Megger; Pressure Test - Mitsubishi Electric FR-E500 Instruction Manual

5.3.4 Insulation resistance test using megger

1) Before performing the insulation resistance test using a megger on the external
circuit, disconnect the cables from all terminals of the inverter so that the test voltage
is not applied to the inverter.
2) For the continuity test of the control circuit, use a meter (high resistance range) and
do not use the megger or buzzer.
3) For the inverter, conduct the insulation resistance test on the main circuit only as
shown below and do not perform the test on the control circuit. (Use a 500VDC
megger.)

5.3.5 Pressure test

Do not conduct a pressure test. The inverter's main circuit uses semiconductors, which
may deteriorate if a pressure test is made.
R (L
Power supply
S (L
T (L
500VDC
megger
Earth terminal
176
PROTECTIVE FUNCTIONS
Motor
Inverter
) U
1
IM
) V
2
) W
3
5