191.5.11 Storage of the UnitThe DC bus of the KEB F5 Combivert is equipped with electrolytic capacitors.If the electrolytic capacitors are stored de-energized, the oxide film working asdielectric fluid reacts with the acidic electrolyte and destroys itself slowly. Thisaffects the dielectric strength and capacity of the unit. If the capacitors startrunning with rated voltage again, the oxide film tries to build up quickly. Thiscauses heat and gas and leads to the destruction of the capacitors.In order to avoid failures, the KEB F5 Combivert must be started up according tothe following specifi cation based on duration of storage period (powered off):Storage Period < 1 Year* Start up normally, without any additional precautionsStorage Period 1...2 Years* Power on frequency inverter for one hour without modulationStorage Period 2...3 Years* Remove all cables from power circuit, including braking resistor and GTR7 connections* Open control release* Connect variable voltage supply to inverter input* Increase voltage slowly to indicated input level and remain at for the specified time.Voltage Class Input Voltage Minimum Time230V 0...160V 15 min160...220V 15 min220...260V 1 h480V 0...280V 15 min280...400V 15 min400...500V 1 hStorage Period > 3 Years* Input voltages same as above, however double the amount of time for each additional year.Eventually consider changing capacitors.
