Instruction manual

Check items
96
7 PRECAUTIONS FOR MAINTENANCE AND INSPECTION
The inverter is a static unit mainly consisting of semiconductor devices. Daily inspection must be performed to
prevent any fault from occurring due to the adverse effects of the operating environment, such as temperature,
humidity, dust, dirt and vibration, changes in the parts with time, service life, and other factors.
z Precautions for maintenance and inspection
For some short time after the power is switched off, a high voltage remains in the smoothing capacitor. When
accessing the inverter for inspection, switch power off, wait for more than 10 minutes, and then make sure that the
voltage across the main circuit terminals P-N of the inverter is not more than 30VDC using a tester, etc.
7.1 Check items
7.1.1 Daily inspection
Basically, check for the following faults during operation.
1) Motor operation fault
2) Improper installation environment
3) Cooling system fault
4) Unusual vibration and noise
5) Unusual overheat and discoloration
During operation, check the inverter input voltages using a tester.
7.1.2 Periodic inspection
Check the areas inaccessible during operation and requiring periodic inspection. For periodic inspection, consult us.
1) Cooling system fault : Clean the air filter, etc.
2) Tightening check and retightening : The screws and bolts may become loose due to vibration, temperature
changes, etc. Check and tighten them.
Tighten them according to the specified tightening torque. (Refer to
page 11.)
3) Check the conductors and insulating materials for corrosion and damage.
4) Measure insulation resistance.
5) Check and change the cooling fan and relay.
z Daily and periodic inspection
Area of
Inspection
Inspection
Item
Description
Interval
Method Criterion Instrument
Customer’s
check
Daily
Periodic*
1 year 2 years
General
Surrounding
environment
Check ambient
temperature, humidity,
dust, dirt, etc.
{
Measure 5cm away from
the inverter.
(Refer to page 6.)
Ambient
temperature: -10°C
to +50°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 and
T phases.
Within permissible
AC (DC) voltage
fluctuation (refer to
page 103)
Tester, digital
multimeter