Maeda MK0003, Service Manual, Page: 320 / 348

5-26
2.8.2 REGULAR MAINTENANCE
Preform periodic inspections every three to six months according to the usage frequency.
DANGER
Regulation
- Perform the following steps before starting the inspection.
(1) Cutoff “OFF” the input power.
(2) Check that the charge lamp is off after 10 minutes has elapsed.
(3) Use a tester that is capable of measuring DC high voltage (more than DC 800V), and check
that the DC main circuit voltage (between PA–PC) is under 45V.
If this step is not performed before inspection, it may lead to an electrical shock.
Prohibited
- Parts must not be replaced.
May result in electrical shock, fire, or injury. Parts replacement must be ordered to the vendor.
■ Places of inspection
1. Whether there are any loose screws on the wiring terminal. Retorque with a driver.
2. Whether there are any faulty standoffs at the wiring terminal standoff positions. Visually inspect for traces of
heat at the places of standoffs.
3. Whether there is any damage on the wiring and cables. Perform visual inspections.
4. Clean off any debris and dust. Remove the debris and dust with an electrical vacuum cleaner. Pay attention to
the ventilation ports and printed boards when cleaning. Unpredicted accidents may occur if debris or dust
accumulates. Keep clean.
5. The large capacity electrolytic capacitors used in the inverter tends to decay if left for a long period without any
electricity flowing.
If not being used for a long period, allow electricity to flow for at least five hours once in two years so that the
large capacity electrolytic capacitors recover their characteristics. Check the inverter operation at the same
time. It is recommended that commercial power shall not be directly connected to the inverter, and equipments
such as thruidakus are used, and the input voltage be raised gradually.
6. When performing insulation tests, use 500V mega, and only perform with the main circuit terminal block as the
target. Never perform insulation tests on control terminals or print boards other than the main circuit. When
performing insulation tests on the motor, disconnect the output terminal U, V, W and perform only on the motor.
When performing insulation tests on surrounding circuits other than the motor, remove all of the wires
connected to the inverter, so that no test voltage flows to the inverter.
(Note) Always remove the wires connected to the main circuit terminal block, and perform on only the inverter
itself.
7. Do not perform pressure tests since it may damage the internal parts.
8. Voltage and temperature check
Recommended amperometer:
Input side → moving iron type amperometer ( )
Output side → Rectifier type amperometer ( )
It is easier to identify abnormalities if the temperature surrounding the inverter is always measured during the
startup, operation, and stop process.