MITSUBISHI ELECTRIC FR-S520 - Manual (Page 159)

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3
3
.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.)
R
S
T
U
V
W
Inverter
Earth terminal
500VDC
megger
Power supply IM
Motor
3
.3.5 Pressure test
Do not conduct a pressure test. The inverter may be deteriorated.
3
.3.6 Daily and periodic inspection
Interval
Periodic*
Ar
e
a
o
f
In
spect
io
n
Inspection
Item
Description
D
a
ily
1 year
2 year
s Method Criterion Instrument
Surrounding
environment
Check ambient
temperature,
humidity, dust,
dirt, etc.
Make
measurement
5cm (1.97inches)
away from
inverter. Ambient
temperature:
-10ºC to +50ºC
(14ºF to 122ºF),
non-freezing.
Ambient
humidity: 90%
or less, non-
condensing. Thermo-
meter,
hygrometer,
recorder
Overall unit
Check for
unusual
vibration and
noise. Visual and
auditory checks. No fault.
Gener
al
Power
supply
voltage Check that main
circuit voltage is
normal.
Measure voltage
across inverter
terminals R-S-T Within
permissible AC
(DC) voltage
fluctuation
(Refer to page
161) Meter, digital
multimeter