PV inverters are composed of structural parts, circuit boards, power switching tubes, capacitors, LCD displays and fans. String inverters are generally designed for 15 years of life if there are no special requirements. The actual service life, on the other hand, is related to the design, material and installation environment of the inverter, which is generally 8 to 15 years. (1) Electrolytic capacitors are indeed one of the most failure-prone devices of inverters, NCC capacitors are currently one of the best capacitors, and its capacitor specification clearly states: "Please note that the projected result is not a guaranteed value, and when designing the life of the equipment, please review the capacitor life margin, and also, if the projected life exceeds 15 years, please take 15 years is the upper limit".
(2) In addition to electrolytic capacitors, there are many components that have a life span of less than 25 years, such as liquid crystal displays, connectors, cables, terminals, and thermally conductive silicone grease.
Air conditioners, refrigerators, televisions and other home appliances are civilian products, the service life is about 8 years, the whole warranty is generally 1 year, while the PV inverter is an industrial-grade product, the service life is 15 years, taking into account the special nature of the inverter, only the manufacturer can repair, so most manufacturers are using a 5-year warranty.
Why few manufacturers have a 10-year warranty, because the PV inverter is a new thing, in addition to the domestic sunlight power, no manufacturer has had 10 years of experience in the operation of the product, the life of the enterprise are not 10 years, but let the product warranty of 10 years, hard to believe.
The inverter is not very mature technically compared to home appliances such as TVs, and it is high temperature and high voltage with high current. 10 years warranty is not just a slogan, it requires a lot of additional costs, such as the inverter needs more derating design, and the after-sales service personnel should be increased a lot, and the service cost will be very high.
In the past, there were 2, 3, 5, 8, 10 years warranties for grid-connected inverter manufacturers. 2 and 3 years warranties are because customers think that the quality of the manufacturers is not up to par and do not go to buy and go out of business, 8 and 10 years warranties for manufacturers, because of high after-sales costs and low profits and bankruptcy, so finally only manufacturers with 5 years warranties are left alive.
