A frequency converter consists of various components. The performance of some components will gradually degrade and age after long-term operation, which is the primary cause of frequency converter failures. To ensure long-term stable equipment operation, the following components shall be replaced regularly:

(1) Cooling Fan The power module of the frequency converter generates the most heat. Heat produced during continuous operation must be dissipated in a timely manner. Generally, the service life of a cooling fan ranges from 10,000 hours to 40,000 hours. For continuously running frequency converters, the fan needs replacement every 2 to 3 years. Direct cooling fans are available in 2-wire and 3-wire types. For 2-wire fans, one wire serves as the positive pole and the other as the negative pole; avoid incorrect wiring during replacement. Apart from positive and negative poles, 3-wire fans are equipped with an additional detection wire. Special attention must be paid during replacement, otherwise an overheating alarm of the frequency converter will be triggered. AC fans are divided into 220V and 380V types; ensure the correct voltage rating during replacement.

(2) Filter Capacitor The filter capacitor in the intermediate DC circuit, also known as the electrolytic capacitor, mainly smooths DC voltage and absorbs low-frequency harmonics in direct current. Heat generated by continuous operation of the capacitor, together with heat from the frequency converter itself, accelerates the drying of electrolyte, which directly affects capacitance. Under normal conditions, the service life of the capacitor is approximately 5 years. It is recommended to inspect the capacitance once every year. A new filter capacitor should be replaced if the capacitance decreases by more than 20%.