Precautions For Maintenance And Inspection; Inspection Items; Daily Inspection; Periodic Inspection - Mitsubishi Electric FR-D720-0.2K-G Instruction Manual

Inspection items

The drive unit 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.
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
drive unit for inspection, wait for at least 10 minutes after the power supply has been switched OFF, and then make sure that
the voltage across the main circuit terminals P/+ and N/- of the drive unit is not more than 30VDC using a tester, etc.
6.1 Inspection items
6.1.1

Daily inspection

Basically, check for the following faults during operation.
(1) Motor operation fault
(2) Improper installation environment
(3) Cooling system fault
(4) Abnormal vibration, abnormal noise
(5) Abnormal overheat, discoloration
6.1.2

Periodic inspection

Check the areas inaccessible during operation and requiring periodic inspection.
For a periodic inspection, contact your sales representative.
(1) Check for 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,
(3) Check the conductors and insulating materials for corrosion and damage.
(4) Measure insulation resistance.
(5) Check and change the cooling fan and relay.
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etc. Check and tighten them.
Tighten them according to the specified tightening torque (refer to page 16).