Insulation Resistance Test Using Megger; Pressure Test - Mitsubishi Electric FR-A520-0.4K -55K 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 be deteriorated if
a pressure test is made.
Area of
Inspection
Inspec- Description
Item
tion
Check ambient
Surrounding
temperature, humidity,
environment
dust, dirt, etc.
General
Check for unusual
Overall unit
vibration and noise.
Power
Check that main circuit
supply
voltage is normal.
voltage
(1) Check with megger
(across main circuit
terminals and
ground terminal).
(2) Check for loose
General screws and bolts.
(3) Check for overheat-
ing of each part.
(4) Clean.
Main
circuit
(1) Check conductors
for distortion.
Conductors,
(2) Check cable
cables
sheaths for
breakage.
Terminal
Check for damage.
block
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R 〈L 〉
Inverter
U
1
Power
S 〈L 〉
V
2
supply
T 〈L 〉
M
3
DC500V
megger
Ground terminal
Daily and Periodic Inspection
Interval
Periodic
Daily 1 2
year years
{
(Refer to page 7)
{
Visual and auditory
checks.
Measure voltage
{
across inverter
terminals R-S-T
〈L
1
{ {
(1) Disconnect all
{
{
(2) Re-tighten.
(3) Visual check.
{
(1), (2) Visual check.
{
{
183
PROTECTIVE FUNCTIONS
Motor
IM
Method Criterion
Ambient
temperature:
(constant torque)
−10ºC to +50ºC,
non-freezing.
(Variable torque)
−10ºC to +40ºC,
non-freezing
Ambient humidity:
90% or less,
non-condensing.
No fault.
Within permissible
AC voltage
fluctuation
(Refer to page
〉.
-L -L
2 3
190)
(1) 5M Ω or more.
cables from (2), (3) No fault.
inverter and
measure across
terminals R, S, T,
V, W 〈L
, L , L ,
1 2 3
V, W〉 and ground
terminal with
megger.
(1), (2) No fault.
Visual check. No fault
Instrument
Thermometer,
hygrometer,
recorder
Meter, digital
multimeter
500VDC class
megger