Chapter 4 Preventive Maintenance; Necessity Of Preventive Maintenance; Maintenance And Inspection; Precautions For Maintenance And Inspection - Mitsubishi Electric FATEC FR-A800 Manual

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PREVENTIVE MAINTENANCE

CHAPTER 4 PREVENTIVE MAINTENANCE

Preventive maintenance consists of daily maintenance and periodic maintenance.
4.1

Necessity of preventive maintenance

It is inefficient to repair the production system after failures occur.
The primary goal is to avoid failures and equipment suspension. Preventive maintenance prevents
critical failures, as well as leading to fast repair in case of failure.
4.2

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.
4.2.1

Precautions for maintenance and inspection

When accessing the inverter for inspection, the smoothing capacitor voltage remains high for a while
after the power supply has been switched OFF. Therefore, wait until the charge lamp turns off and
then make sure that the voltage across the main circuit terminals P/+ and N/- of the inverter is not
more than 30 VDC using a tester.
4.2.2

Inspection items

(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) Abnormal overheat and discoloration
(2) Periodic inspection
● Check the areas inaccessible during operation and requiring periodic inspection.
1) Check for cooling system fault. ............................. Clean the air filter, etc.
2) Check the tightening and retighten the screws. .... The screws and bolts may become loose
3) Check the conductors and insulating materials for corrosion and damage.
4) Measure the insulation resistance.
5) Check and change the cooling fan and relay.
4.1 Necessity of preventive maintenance
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due to vibration, temperature changes,
etc. Check and tighten them.