Hitachi SJ700-2 Series service manual Replacing Parts

5.6Replacing 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 and maintenance
	replacement	methods
	interval
Cooling fan	10 years	Replace with a new part.
DC bus capacitors of	10 years	Replace with a new part. (Decide
main circuit		whether to replace after
		examination.)
Electrolytic capacitors	10 years	Replace with a new part. (Decide
on the board		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.

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