Tescom DS300SHPA Series User Manual Download

Page: 50 / 71

The AC inputs of all UPSs in the parallel system are connected to the same mains, and all the AC

outputs are connected to each other. Each UPS has its own battery group. The critical load is connected to
the common output of the parallel system. There are also some signal cable connections between the UPS
units necessary for parallel operation, and will be described later.

5.2

Parallel Operation Mode settings of DS300SHPA Series UPSs

NOTE: Parallel operation hardware (parallel communication board) are not installed in a
standard DS300SHPA series UPS, but parallel operation option is available and can easily
be added to all UPSs.

N+1 REDUNDANT parallel operation

For parallel operation some parameters must be given by the service personnel these are:

1- Select Parallel mode must be selected from ADJUST MENU (ADJUST MENU/INV FACTORY

OPTIONS/OPERATING MODE:)

2- A unique UPS network no must be given from ADJUST MENU(ADJUST MENU/INV FACTORY

OPTIONS/UPS NO:) (each UPS must be assigned a unique UPS number)

3- Minimum UPS quantity requirement must be given from ADJUST MENU (ADJUST MENU/INV

FACTORY OPTIONS/N+1 MINIMUM:) (N number in the system)

Shown parameters can not be adjust by the user, these parameters are located on ADJUST MENU also
adjust menu is password protected only authorized service personnel can access this menu.

PARALLEL mode

This  mode  is  used  for  operation  of  at  least  two  (1+1  configuration)  UPS  units  connected  in  parallel  for
increased  reliability.  If  this  mode  is  selected,  the  load  is  shared  equally  by  each  UPS  available  in  the
parallel system (N+1 numbers of UPS units), during normal operation.

    In case of a failure of any one of the UPS units, the faulty UPS is isolated from the parallel system and
the  critical  load  is  supplied  by  the  remaining  N  number  of  UPSs.  If  any  one  of  those  UPS  units  fails  too,
then the critical load is transferred to bypass supply via the static bypass switches of the parallel connected
UPSs. If the faulty UPS returns to normal operation, it joins the parallel system again and starts sharing the
load.

In parallel mode, the total VA rating of the parallel system is equal to the VA rating of a single UPS
multiplied by N.

In  parallel  mode,  you  will  see  ‘’PARALLEL  MODE  /MS’’(master  UPS)    or  ‘’PARALLEL  MODE  /sl’’  (slave
UPS) message on the LCD panels of all the all UPS units.

   More  detailed  diagrams  for  two  (or  more)  DS300SHPA  series  UPSs  connected  in  parallel  are  given  in
Figures 4.2 and 4.3

Communication between parallel UPSs are provided over one pair cable (PCC06). The length of the cable
is limited up to six meters.
A  link  cable  is  used  for  connecting  the  first  UPS  to  the  last  UPS  ,this  cable  is  redundant  for  normal
communication cables.
If communication is lost on SLAVE UPS the UPS will shutdown but the MASTER UPS will go on running if
the communication is provided at SLAVE UPS it will start automatically again.