Tescom T-300P Series, User Manual

Page: 22 / 45

18
The general diagram of parallel connection is shown below:
Figure 3-1 Parallel connected UPS’s
The inputs of two UPS’s are connected to mains; outputs of two UPS’s are connected to each other. There are two
battery groups.
SB1 and SB3 static bypass switches work always together. They turn on/off together. If these static switches are
conducting the load is connected to mains directly.
SB2 and SB4 static switches work always together. If these static switches are conducting, the load is connected to
inverter. In this position current sharing is active.
If a failure occurs in one UPS, bypass system transfers the load to bypass.
At this mode, power capacity is higher than only one UPS.
3.2.2 Redundant Parallel Mode
At this mode if one of the UPS’s fails the other UPS continues to supply the load.
Assume that UPS1 on figure 3-1 is failed,SB1 and SB2 static switches will turn off and the UPS 1 is isolated from
load. The SB4 static switch of the UPS 2 will stay in conducted position and it continues to supply the load.
If UPS 1 is okay after a delay this UPS will join the system.
If two UPS’s are in failure SB1 and SB3 static switches will turn on and load is transferred to bypass
This is a 3 level redundancy UPS1+UPS2,UPS2,mains
Current sharing is active in this mode.
In this mode the power of load must be lower than or equal to 1 UPS power.
In this mode, on the LCD panel of both UPS’s you will see the message “REDUNDANT MODE”.
MB1
SB1
UPS1
CB1
AC/DC -1
BATT.1
INVERTER 1
SB2 CB2
MB2
SB3
UPS2
CB3
AC/DC -2
BATT.2
INVERTER 2
SB4 CB4
OUTPUT
LINE
S1
S2
S3
S4
S1
S2
S3
S4