21. Brief IntroductionThe Online EX Series is an uninterruptible power supply incorporatingdouble-conversion technology, optional EPO and maintenance switch,parallel redundancy. It provides perfect protection specifically for computerequipment, communication systems and computerized instruments.Its true online double-conversion design eliminates all mains powerdisturbances. A rectifier converts the alternating current from the utilitypower to direct current. This direct current charges the batteries andpowers the inverter. On the basis of this DC voltage, the invertergenerates a pure sinusoidal AC voltage, which is constantly powering theloads.In the event of power failure, the maintenance-free batteries power theinverter. If overload or inverter failure, UPS will work on bypass mode topower with mains power. After load become normal, it will still work onbattery mode.This manual is applicable to the following models:l EX6K: Standard model with built-in batteries.l EX6KL: Long backup time model, it is able to connect with theexternal battery bank.l EX10K: Standard model with built-in batteries.l EX10KL: Long backup time model, it is able to connect with theexternal battery bank.l EX3110KL: three-phase input and single-phase output, long backuptime models, it is able to connect with the external battery bank.l EX3115KL: three-phase input and single-phase output, long backuptime models, it is able to connect with the external battery bank.l EX3120KL: three-phase input and single-phase output, long backuptime models, it is able to connect with the external battery bank.Above all models contain standard rev and professional rev, User canselect corresponding model by its requirement, compared with standardrev, professional rev (Model number with “P”) has EPO switch and bypassmaintenance switch built-in, about the function of EPO and bypassmaintenance switch please refer to 2.8 and 2.9.