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NE Series (20-30kVA)
User Manual
Chapter 2 Overview
AC
Figure2-2 The basic work principle block diagram of NE Series (20-30kVA)
2.3.2
Work Mode
NE Series (20-30kVA) UPS has 4 work modes: mains mode, battery mode, bypass mode, and
maintenance bypass mode.
Mains mode
When mains are normal, the rectifier converts AC power to DC power, and then charges the battery. It
also supplies power for load.
Battery Mode
When mains are abnormal, the rectifier will automatically turn to battery input and supply power to
inverter after battery boosting so as to protect output loads from AC power interruptions.
Bypass Mode
When the inverter is abnormal (such as over-temperature, short circuit, output voltage abnormal,
overload and surpasses the power range that the inverter can withstand), the inverter will shut down
automatically to prevent damage. If the mains are still normal at this moment, the static switch will
turn to bypass to supply AC power directly to the load.
Maintenances Bypass Mode
When UPS needs to be maintained or change the battery, and the power must not be interrupted at the
same time, users can first shut down the inverter switch, and then turn on the maintenance bypass
switch, then turn off the battery, mains and bypass switches. Under the mode, AC power goes through
maintenance bypass switch to supply power to load. At this time, there is no electricity inside the UPS
(except N), and the maintainer can perform the maintenance safely.
Maintenance
switch
Bypass
input
Mains SCR
PFC
DC/DC
DC/AC
Load
Mains
Battery
SCR
Battery
input
Charger
