A SERVICE OF

logo

Open as PDF
next previous
211
PRECAUTIONS FOR MAINTENANCE AND INSPECTION
6
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-
tion
Inspec
tion
Item
Description
Interval
Method Criterion Instrument
Cus-
tomers
check
Daily
Periodic
1
year
2
year
General
Sur-
round-
ing
environ-
ment
Check ambient
temperature, humidity,
dust, dirt, etc.
{ (Refer to page 10)
Ambient
temperature:
(constant torque)
-10°C to +50°C,
non-freezing.
(Variable torque)
-10°C to +40°C,
non-freezing
Ambient humidity:
90% or less,
non-condensing.
Thermometer,
hygrometer,
recorder
Overall
unit
Check for unusual
vibration and noise.
{
Visual and
auditory checks.
No fault.
Power
supply
voltage
Check that the main
circuit voltages are
normal.
{
Measure voltages
across the inverter
terminal block R-
S-T phases.
Within
permissible AC
voltage fluctuation
(Refer to page
220.)
Tester, digital
multimeter
Main
circuit
Gen-
eral
(1) Check with megger
(across main circuit
terminals and earth
(ground) terminal).
(2) Check for loose
screws and bolts.
(3) Check for overheat
traces on the parts.
(4) Clean.
{
{
{
{ (1) Disconnect all
cables from the
inverter and
measure
across
terminals R, S,
T, V, W and
earth (ground)
terminal with
megger.
(2) Re-tighten.
(3) Visual check.
(1) 5M Ω or
more.
(2), (3) No fault.
500VDC
class megger
Conduc-
tors,
cables
(1) Check conductors
for distortion.
(2) Check cable
sheaths for
breakage.
{
{
(1), (2) Visual
check.
(1), (2) No fault.
Term i-
nal
block
Check for damage. { Visual check. No fault
U
V
W
IM
Inverter
Motor
Power
supply
500VDC
megger
Earth (ground) terminal
R
S
T