Section IV
Multiple UPS Configurations
006-0007068 UPS-1500-S-2S Guide
Rev E
32 of 60
09/10/20
Expanded Paralleling -R Option
The “R” option adds an electronic breaker to the AC output of the UPS to provide fault-tolerant,
glitch-free parallel operation. Should one unit experience a fault that could otherwise cause the
AC output to collapse, the breaker disconnects the failed unit from the AC bus. This allows the
remaining units to continue delivering power, provided the remaining units can support the total
load power. This allows users to create N+1 or N+M redundant systems.
Additionally, the “R” option increases the total number of units in a multi-unit system to 32.
These units can be arranged to form single-phase, Split Phase, and 3-Phase systems. Systems
with multiple phases will be N+1 or N+M redundant on each phase.
A failed unit can be removed and replaced while the system AC output is active. Special
consideration must be taken when connecting the outputs to avoid electric shock. It is strongly
recommended that the system AC output be disabled before a unit is removed or replaced.
CONFIGURATION cables for two unit and three unit single-phase systems are offered as standard
products. See the following pages for details. These cables are unique to the –R paralleling option,
and cannot be used with –F paralleling option units. Contact the SynQor factory for Single Phase
systems larger than 3 UPS units, or for Split Phase and 3-Phase systems.
Systems created using expanded parallel UPS units will be fault-tolerant to the following events:
• Complete loss of power source (AC INPUT, DC INPUT, BATTERY)
• Hardware failure of the AC input stage
• Hardware failure of the AC output stage
The enable and disable behavior of systems using expanded paralleling is different from systems
using standard paralleling. For expanded paralleling, all UPS units will be enabled if one UPS is
enabled. Units can be enabled by actuating their front-panel “on” switches or by sending the
appropriate signal over their USER I/O cables.
Sending a “OUTPUT DISABLE” command to a UPS will cause only that UPS to be disabled. Other
UPS units in the system will continue running. Sending a “SYSTEM DISABLE” command over the
RS-232 interface will cause all UPS units in a system to turn off simultaneously.
For a detailed description of the terminal interface see the SynQor website at:
http://www.SynQor.com/UPS/documents/UPS_User_Commands.pdf
