Hitachi NES1-002LB, Quick Reference Manual

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Chapter 11 Maintenance and Inspection
11 - 1
11.1 Precautions for Maintenance and Inspection
WARNING
- Before inspecting the inverter, be sure to turn off the power supply and wait for 10 minutes or more.
Otherwise, you run the risk of electric shock.
(Before inspection, confirm that the Charge lamp on the inverter is off.)
In case the power indication of the operator does not turn ON after power-up, inverter may be
damaged. In that case, the inspection must be done after waiting 2 hours or more of the power OFF.
Otherwise there is a danger of electric shock and/or injury.
- Commit only a designated person to maintenance, inspection, and the replacement of parts.
(Be sure to remove wristwatches and metal accessories, e.g., bracelets, before maintenance and
inspection work and to use insulated tools for the work.) Otherwise, you run the risk of electric shock
and injury.
- Never modify the inverter. Otherwise, you run the risk of electric shock and injury.
(A) Daily inspection
Basically check your system during the inverter operation to confirm that:
1) the motor is operating according to the settings on the inverter,
2) the installation environment is normal,
3) the cooling system is normal,
4) no abnormal vibrations and noise are generated,
5) no equipment overheating and discoloration are found, and
6) there are no unusual smells.
While the inverter is operating, measure the inverter input power voltage with a multimeter to confirm that:
1) the power supply voltage does not fluctuate often
2) the voltages between the power supply wires are balanced.
(B) Cleaning
Always keep the inverter clean. When cleaning the inverter, wipe off dirt and stains on the inverter surface
lightly with a soft cloth dipped in a neutral detergent solution.
Note:
Do not use solvents such as acetone, benzene, toluene, and alcohol for cleaning. These solvents cause
the inverter surface to dissolve or the coating on the surface to peel off. In particular, never use a detergent
or alcohol to clean the monitor of the digital operator.
(C) Periodic inspection
Check those inverter sections and parts which are accessible only while the inverter is power off and which
should be inspected regularly. When you intend to carry out a periodic inspection, contact your local
Hitachi Distributor.
During a periodic inspection, perform the following:
1) Check that the cooling system is normal. Clean the air filter as needed.
2) Check the screws and bolts for tightness, and retighten them. Screws and bolts may have loosened
because of vibrations and temperature changes. Check them carefully.
3) Check to ensure conductors and insulators are not corroded or damaged.
4) Measure the dielectric breakdown voltage of insulators.
5) Check the cooling fan, smoothing capacitors, and relays, and replace them if necessary.
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