Insulation Resistance Test Using Megger; Pressure Test; Daily And Periodic Inspection - Mitsubishi Electric FR-A500 Instruction Manual

6.1.4

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.)
6.1.5

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.
6.1.6

Daily and periodic inspection

Area of
Inspec-
Inspec- Description
tion Item
tion
Surround-
Check ambient
ing
temperature, humidity,
environ-
dust, dirt, etc.
ment
General
Overall Check for unusual
unit vibration and noise.
Power Check that the main
supply circuit voltages are
voltage normal.
(1) Check with megger
(across main circuit
terminals and earth
(ground) terminal).
(2) Check for loose
screws and bolts.
General (3) Check for overheat
traces on the parts.
(4) Clean.
Main
circuit
(1) Check conductors
Conduc- for distortion.
tors, (2) Check cable
cables sheaths for
breakage.
R 〈 L 〉 Inverter
1
Power
S 〈 L 〉
2
supply
T 〈 L 〉
3
500VDC
megger
Earth (ground) terminal
Interval
Periodic
Daily
1 2
year year
(Refer to page 10)
Visual and auditory
checks.
Measure voltages
across the inverter
terminal block R-S-
T <L1-L2-L3>
phases.
(1) Disconnect all
(2) Re-tighten.
(3) Visual check.
(1), (2) Visual
check.
207
PRECAUTIONS FOR MAINTENANCE AND INSPECTION
Motor
U
V IM
W
Method Criterion
Ambient
temperature:
(constant torque)
-10 C to +50 C
(14 F to 122 F),
non-freezing.
(Variable torque)
-10 C to +40 C
(14 F to 104 F),
non-freezing
Ambient humidity:
90% or less,
non-condensing.
No fault.
Within permissible
AC voltage
fluctuation (Refer
to page 216)
(1) 5M or more.
cables from the
inverter and
measure across
terminals R, S,
T, U, V, W <L ,
1
L , L , U, V,
2 3
W> and earth
(ground)
terminal with (2), (3) No fault.
megger.
(1), (2) No fault.
Cus-
Instrument tomers
check
Thermo-
meter,
hygrometer,
recorder
Tester,
digital
multimeter
6
500VDC
class
megger