Toshiba Tosvert VF-A5 - Manual (Page 109)

12.2 Component Replacement
The inverter is composed of various electronic components including semiconductor elements.
Periodic inspection of the following components is necessary, as their characteristics will change over time
due to their structure or material. This may cause inverter performance to"decrease and may lead to more
serious failures.
1) Cooling fan
The lifetime of the cooling fan (used to cool heat-generating components such as the main circuit
semiconductor elements) is approx. 30,000 hours (approx. 2 to 3 years of continuous operation). If
abnormal noise or vibration is detected during a periodic inspection and the fan is determined to be
the cause, it must be replaced.
2) Smoothing capacitor
Large-capacity aluminum electrolytic capacitors are used for smoothing in the main circuit DC section.
The characteristics of these capacitors will deteriorate over time due to ripple currents, etc. The time
period involved is largely dependent upon the ambient temperature and the operating conditions, but
when operated under normal conditions, replacement is required approx, every 5 years.
(On 3.7kW and smaller units, the smoothing capacitors are located on the PCS, so the PCS must also
be replaced.)
Capacitor appearance inspection and evaluation standards:
a) Is any fluid leaking?
b) Is the knob (safety valve) protruding or expanded?
c) Measure the capacitance and leakage current.
* A time guideline for the replacement period of these components can be established by checking the
cumulative run time monitor.
Table 12-1 Standard component replacement periods
Part name Standard replacement period
Cooling fan
Smoothing capacitors
2 to 3 years (Approx. 30,000 hours)
5 years
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