5.3 Precautions for Maintenance and Inspection
PROTECTIVE FUNCTIONS
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5.3 Precautions for Maintenance and Inspection
The transistorized inverter is a static unit mainly consisting of semiconductor devices.
Daily inspection must be performed to prevent any fault from occurring due to adverse
influence by the operating environment, such as temperature, humidity, dust, dirt and
vibration, changes in the parts with time, service life, and other factors.
5.3.1 Precautions for maintenance and inspection
For some short time after the power is switched off, a high voltage remains in the
smoothing capacitor. Therefore, when more than 10 minutes have elapsed after
power-off, make sure that the voltage across the main circuit ter -
−
of the
inverter is 30VDC or less using a meter, etc. Then, access the inverter for inspection.
5.3.2 Check items
(1) Daily inspection
!
Check the following:
1) Motor operation fault
2) Improper installation environment
3) Cooling system fault
4) Unusual vibration and noise
5) Unusual overheating and discoloration
!
During operation, check the inverter input voltages using a meter.
(2) Cleaning
Always run the inverter in a clean state.
When cleaning the inverter, gently wipe dirty areas with a soft cloth immersed in
neutral detergent or ethanol.
Note:
Do not use solvent, such as acetone, benzene, toluene and alcohol, as they
will cause the inverter surface paint to peel off.
Do not use detergent or alcohol to clean the display and other sections of the
control panel as these sections may deform.
5.3.3 Periodic inspection
Check the areas inaccessible during operation and requiring periodic inspection.
(1) Cooling system: ......Clean the air filter, etc.
(2) Screws and bolts: ...These parts may become loose due to vibration, temperature
changes, etc. Check that they are tightened securely and
retighten as necessary.
(3) Conductors and insulating materials: Check for corrosion and damage.
(4) Insulation resistance: Measure.
(5) Cooling fan, smoothing capacitor: Check and change if necessary.
