MY-A Series (10kVA-20kVA) UPS
User Manual
2 Overview
19
AC
DC
DC
AC
Bypass input
Mains input
Battery input
Bypass static switch
Charge
Rectifier
Inverter
Maintenance bypass
Output
DC
DC
Discharge
Figure2-8
Work principle diagram
The MY series UPS includes rectifier/PFC, inverter, charger, bypass static switch etc function module,
the input power includes mains input, bypass input, battery input, the output mode includes inverter
output, bypass output and maintenance bypass output (if equipped).
When mains is normal, the rectifier starts and the charger charges the battery at the same time. When
UPS off, if bypass is normal, the system turns to bypass output; when UPS on, the mains boosts by
rectifier/PFC and output DC bus voltage, and then go through inverter and output pure sine-wave AC
power, the output turns to inverter output to load from bypass output (if equipped).
When mains is abnormal, the battery voltage boosts by rectifier/PFC and output DC bus voltage, and
then go through inverter and output pure sine-wave AC power to load. When mains recover normal,
the UPS turns to mains mode from battery mode automatically.
2.2.2 Work Mode
There are 5 work modes of the UPS: normal mains power supply mode, battery inverter mode,
bypass power supply mode, ECO power supply mode and maintenance bypass power supply mode.
Normal mains power supply mode
When mains power is normal, the UPS works in mains inverter status and charge the battery at the
same time. The work mode is as shown in Figure2-9.
