Section IV
Multiple UPS Configurations
006-0007129 10/12/2018
Rev B
42 of 60
UPS-1500 3-Phase Guide
www.synqor.com
Multi-unit AC OUTPUT “ON/OFF” Control – Expanded Parallel (“R” option)
For expanded parallel multi-unit operation, any “ON” front panel switch actuation will cause
all AC outputs to turn “ON” at once. The “REMOTE-ON” rear panel signal can also be used for a
coordinated start.
Any “OFF” front panel switch actuation will cause only that specific unit to be deactivated. All
other units will continue to function, assuming the load can be supported with the remaining
active units. In addition, the “REMOTE-ON” or “REMOTE-OFF” rear panel input signal may be
utilized to enable and disable one specific unit.
For coordinated shutdown, the user must send “SYSTEM DISABLE” over RS-232. See Section VI
of the Operator’s Guide for details on the RS-232 interface. See UPS Terminal Commands
document for more information on the “SYSTEM DISABLE” command.
AC OUTPUT Neutral Grounding
UPS units combined in multi-unit configurations must have the neutral floating “F” factory
option to prevent the possibility of circulation protective earth currents. Expanded parallel
units, “R” option, come with a floating neutral wire by default. If a grounded output neutral is
required, then the output neutral should be connected to protective earth ground (PEGND) in
a single spot. The size of the neutral-to-PEGND connecting conductor must be sized to match
the largest combined AC OUTPUT neutral conductor specified in the wiring diagrams above.
Wiring Caution
WARNING: LETHAL VOLTAGES MAY BE PRESENT ON UPS AC OUTPUT
CONNECTIONS. ALWAYS REMOVE BATTERY PACKS AND INPUT POWER BEFORE
MAKING MULTI-UNIT AC OUTPUT CONNECTIONS. ALL AC OUTPUT CABLE
CONNECTORS MUST BE INSTALLED DURING OPERATION AS A DISCONNECTED
CABLE CONNECTOR MAY HAVE EXPOSED VOLTAGE PRESENT FROM ANOTHER
UNIT IN THE GROUP.
