OPTI-UPS DS120KC33 - Manual (Page 18)

2-4-5 EPO switch (fig. 2-4-5)
Load
Battery
Pack
+ -
Utility
S3
Input
protection
Input
switch
Manual bypass switch
S6
S.T.S. Rectifier
S4
Battery
switch
Inverter Transformer
S5
Output
switch
S1
Battery
auxility
switch
AC choke DC choke
Fig 2-4-5
Be sure the to check if the EPO is switch otherwise it will not be possible to start up the UPS and no
voltage will be supplied to the output load.