Hitachi WJ Series

Chapter 16 Maintenance and Inspection
16-2-3
16.2.2 Megger® Test
 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.
 In the control circuit carry out a conduction test, use a tester (with high resistance range), do
not use a megger® or buzzer/continuity tester.
 Use a 500 VDC megger® for the megger® test.
 For the megger® test of the inverter main circuit, short-circuit the terminals [R/L1], [S/L2],
[T/L3], [U/T1], [V/T2], [W/T3], [P/+], [PD/+1], [N/-], and [RB] with wires as shown in the figure
below.
 As a result of the megger® test, if the resistance value is 5 MΩ or higher, it is normal.
16.2.3 Withstand Voltage Test
 Do not carry out a withstand voltage test for the inverter.
 The test may damage its internal parts, deteriorating the inverter.
M
R/L1
T/L3
U/T1
V/T2
W/T3
P/+
PD/+1
N/-
RB
Power
supply
Motor
500 VDC megger®
Do not connect
power supply
wires.
Do not connect wires to
the motor.
Ground
S/L2