Hitachi SJ700-2 Series, Service Manual

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5.6 Replacing Parts
The inverter consists of many parts and it functions normally only when all the parts operate normally.
The table below lists the parts that may be subject to changes in characteristics and malfunctions after long-time use,
even normally, over a specified number of years.
Each part should be replaced at specified intervals to prevent inverter faults and changes in inverter characteristics.
Be sure to periodically replace the parts for preventive maintenance.
Part name Standard
replacement
interval
Replacement and maintenance
methods
Cooling fan 10 years Replace with a new part.
DC bus capacitors of
main circuit
10 years Replace with a new part. (Decide
whether to replace after
examination.)
Electrolytic capacitors
on the board
10 years Replace with a new part. (Decide
whether to replace after
examination.)
Relay - Inspect the part after examination.
(1) Cooling fans
The inverter has cooling fans to cool the internal heat-generating parts. The service life of each cooling-fan bearing
is assumed to be about 100,000 hours, though it may vary depending on the inverter operating environment.
On an inverter being run continuously, the cooling-fan unit must usually be replaced at 10-year intervals. Even
during the expected 10-year lifespan, the cooling-fan unit must be immediately replaced in case any abnormal
vibrations or sounds are detected when inspecting the inverter.
1) Removing the molded-case type of cooling-fan unit
<1> Remove the terminal block cover and front cover.
<2> Confirm that the Charge lamp goes off.
<3> While pushing in the claws of the cooling-fan mounting plate,
lift the plate to remove it from the inverter.
<4> Remove the fan connector.
<5> Remove the cooling fans from the cooling-fan mounting plate.
2) Mounting the molded-case type of cooling-fan unit
<1> Attach the cooling fans to the cooling-fan mounting plate so that
the fans are correctly oriented.
<2> Connect the fan connector to terminal J21 or J22 (depending on the
inverter model) of the main circuit board.
<3> Mount the cooling-fan mounting plate on the inverter.
<4> Mount the front cover and terminal block cover.
Position the
cooling-fan unit
so that its
nameplate faces
this side.