Toshiba VF-A7 instruction manual Replacement of expendable parts

■Replacement of expendable parts

The inverter incorporates a great deal of electronic parts such as semiconductors, etc. The following parts deteriorate because of their constructions, physical characteristics and aging. If those parts are used as they have aged, it may cause the inverter to deteriorate in performance and to become faulty. Such being the case, the inverter needs periodical inspection for preventing itself from failure and deterioration.

Note: Service life of part is affected by ambient temperature and operating conditions. Service life of main parts shown below is just standard when the inverter is used in the usual environmental conditions.

1)Cooling fan

Service life of the cooling fan to cool down heat generation parts is 30000 hours (2 to 3 years under continuous operation) approximately. If it generates unusual noise or vibration, it is a sign of replacement.

2)Aluminum electrolytic capacitor

The aluminum electrolytic capacitor of the DC main circuit deteriorates in characteristic because of influence of ripple current, etc. If the inverter is used in the usual operating condition, the capacitor needs to replace every five years. For the inverter that applicable motor output is 3.7 kW or less, replace the capacitor together with the printed circuit board.

<Criteria of external inspection>

･No liquid leak

･Proper setting of safety valve

･Measurement of electrostatic capacity and insulation resistance

Aim of replacement time of each component part can be fixed by checking operation hours of the inverter. For the replacement of parts, contact Toshiba branch office printed on the back cover of this manual. (Operation hours can be known by alarm output, if it is set.)

■Standard period of years to replace main component parts

If the inverter is used under the standard operating conditions (ambient temperature: 30℃ on

average, load factor: 80 % or less, 12-hours operation a day), standard period of years to replace main component parts is as shown below. The following period does not indicate the estimated end of service life of the part but indicates the period that failure rate of the part becomes sharply high thenceforth.

Part name	Standard period	Replacement method, others
	for replacement
Cooling fan	2 to 3 years	Replace with new one.
Main circuit capacitor	5 years	Replace with new one (depending on
		inspection result).
Contactor, Relay, etc.	－	Depending on inspection result
Timer	－	Depending on operation hours
Fuse	10 years	Replace with new one.
Aluminum electrolytic capacitor	5 years	Change together with printed circuit
		board for new board (depending on
on printed circuit board
		inspection result).

Note: Service life of part differs depending on operating environment.

M-3