Hitachi SJ300 Series Spare parts, Capacitor Life Curve, Used, Notes, Spare, Symbol, Quantity, Part description

6–12

Maintenance and Inspection

Spare partsCapacitor Life Curve

We recommend that you stock spare parts to reduce down time, including parts listed below:

Part description	Symbol	Quantity		Notes
		Used	Spare
Cooling fan	FAN	1, 2, 3... (depends	1 or 2	Fan unit at top of housing
		on model)		in all models
Auxiliary cooling fan	FAN	0 or 1... (depends	0 or 1	–150Lxx, –185Lxx, and
		on model)		–220Lxx models
Capacitor bank	CB	1	1	All models

The DC bus inside the inverter uses a large capacitor as shown in the diagram below. The capacitor handles high voltage and current as it smooths the power for use by the inverter. So, any degradation of the capacitor will affect the performance of the inverter. The capacitor bank in SJ300 series inverters is replaceable. This section will show you how to replace it in the field.

Power				Variable-frequency Drive
Input
		Converter		Internal DC Bus				Inverter
	L1/R
										Motor
						+
	L2/S
			Rectifier		+				U/T1
	L3/T								V/T2
							–		W/T3

Troubleshooting and Maintenance

Capacitor life is reduced in higher ambient temperatures, as the graph below demonstrates. Be sure to keep the ambient temperature at acceptable levels, and perform maintenance inspections on the fan, heat sink, and other components. If the inverter is installed on a cabinet, the ambient temperature is the temperature inside the cabinet.

	Capacitor Life Curve
Ambient
temperature, °C 50	12 hrs / day operation

40

30

20

0

1 2 3 4 5 6 7 8 9 10 Years