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2.4.2 PERIODICAL INSPECTION
Make a periodical inspection at intervals 3 or 6 months depending on the operating conditions.
k DANGER
Mandatory
•Before inspection, perform the following steps.
(1) Shut off all input power to the inverter.
(2) Wait at least ten minutes and check to make sure that the change lamp is no longer lit.
(3) Use a tester that can measure DC voltages (800V DC or more), and check that the voltage to the DC
main circuits (across PA-PC) does not exceed 45V.
Performing an inspection without carrying out these steps first could lead to electric shook.
Prohibited
•Never replace any part.
This could be a cause of electric shock, fire and bodily injury. To replace parts, call the local sales
agency.
■ Check items
1. Check to see if all screwed terminals are tightened firmly. If any screw is found loose, tighten it again with a screwdriver.
2. Check to see if all caulked terminals are fixed properly. Check them visually to see that there is no trace of overheating around
any of them.
3. Check all cables and wires for damage. Check them visually.
4. Remove dirt and dust. With a vacuum cleaner, remove dirt and dust. When cleaning, clean the vents and the printed circuit
boards. Always keep them clean to prevent an accident due to dirt or dust.
5. If no power is supplied to the inverter for a long time, the performance of its large-capacity electrolytic capacitor declines.
When leaving the inverter unused for a long time, supply it with electricity once every two years, for 5 hours or more each, to
recover the performance of the large-capacity electrolytic capacitor. And also check the function of the inverter. It is advisable
not to supply the commercial power directly to the inverter but to gradually increase the power supply voltage with a transformer,
etc.
6. If the need arises, conduct an insulation test on the main circuit terminal board only, using a 500V insulation tester. Never
conduct an insulation test on control terminals other that terminals on the printed circuit board or on control terminals. When
testing the motor for insulation performance, separate it from the inverter in advance by disconnecting the cables from the
inverter output terminals U, V and W. When conducting an insulation test on peripheral circuit other than the motor circuit,
disconnect all cables from the inverter so that no voltage is applied to the inverter during the test.
(Note) Before an insulation test, always disconnect all cables from the main circuit terminal board and test the inverter
separately from other equipment.
7. Never test the inverter for pressure. A pressure test may cause damage to its components.
8. Voltage and temperature check
Recommended voltmeter: Input side … Moving-iron type voltmeter (
)
Output side … Rectifier type voltmeter (
)
It will be very helpful for detecting a defect if you always measure and record the ambient temperature before, during and after
the operation.
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