Instruction manual

Check items
97
PRECAUTIONS FOR MAINTENANCE AND INSPECTION
7
* Values in parentheses indicate those for 400V class.
*Consult us for periodic inspection.
Main circuit
General
(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, U,
V, W and earth
(ground) terminal
with megger.
(2) Retighten.
(3) Visual check.
(1) 5M
Ω or more.
(2), (3) No fault.
500VDC
class megger
Conductors,
cables
(1) Check conductors
for distortion.
(2) Check cable
sheaths for
breakage.
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(1), (2) Visual check. (1), (2) No fault.
Terminal block Check for damage.
{ Visual check No fault
Relay
(1) Check for chatter
during operation.
(2) Check for rough
surface on contacts.
{
{
(1) Auditory check.
(2) Visual check.
(1), (2) No fault.
Resistor
(1) Check for crack in
resistor insulation.
(2) Check for break in
the cable.
{
{
(1) Visual check.
Cement resistance,
wire-wound resistor.
(2) Disconnect one end
and measure with
tester.
(1) No fault.
(2) Indication
Control
circuit
Protective
circuit
Operation
check
(1) Check balance of
output voltages
across phases with
the inverter
operated alone.
(2) Perform sequence
protective operation
test to ensure no
fault in protective
and display circuits.
{
{
(1) Measure voltages
across the inverter
output terminals U-V-
W.
(2) Simulatively short or
open the protective
circuit output
terminals of the
inverter.
(1) Phase-to-phase
voltage balance
within 4V (8V) for
200V (400V).
(2) Fault must occur
because of
sequence.
Digital
multimeter,
rectifier type
voltmeter
Cooling
system
Cooling fan
(1) Check for unusual
vibration and noise.
(2) Check for loose
connection.
{
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(1) Turn by hand with
power off.
(2) Visual check.
No unusual vibration
and noise.
Display
Display
(1) Check for LED lamp
blown.
(2) Clean.
{
{
(1) Lamps indicate
indicator lamps on
panel.
(2) Clean with rag.
(1) Check that lamps
are lit.
Meter
Check that reading is
normal.
{
Check the readings of
the meters on the panel.
Must satisfy
specified and
management
values.
Voltmeter,
ammeter, etc.
Motor
General
(1) Check for unusual
vibration and noise.
(2) Check for unusual
odor.
{
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(1) Auditory, sensory,
visual checks.
(2) Check for unusual
odor due to
overheat, damage,
etc.
(1), (2) No fault.
Insulation
resistance
Check with megger
(across terminals and
earth (ground)
terminal).
{
Disconnect cables from
U, V, W (including motor
cables).
5M
Ω or more. 500V megger
Area of
Inspection
Inspection
Item
Description
Interval
Method Criterion Instrument
Customer’s
check
Daily
Periodic*
1 year 2 years