Section IV
Multiple UPS Configurations
006-0006504 02/27/18
Rev R
36 of 56
UPS-3000 Guide
www.synqor.com
3-Phase Connection of AC Outputs
Three UPS units can have their AC OUTPUTs connected such that they share a common “neutral”
and then controlled such that their output voltages are phased by 120 degrees (one- third cycle)
from each other. This creates a three-phase output where the line-to-neutral voltage is the rated
voltage of the individual UPS units (e.g. 115Vac or 230Vac line-to-neutral) and the line-to-line
voltage is 1.73 times higher (e.g. 200Vac or 400Vac line-to-line).
The wiring diagram for the AC OUTPUT cables and the CONFIGURATION cables for the 3-Phase
configuration is shown below:
L2
N
PEGND
L1
N
PEGND
L3
N
PEGND
Line 2
Line 1
Line 3
L3 N
L2 L1
PEGND
CONFIGURATION cable SYN-9317
AC OUTPUT
AC OUTPUT
AC OUTPUT
If the user is providing the AC OUTPUT cable, all the cable sections should have the
following minimum wire size, depending on whether the AC OUTPUT of the individual UPS
units is 115 Vac or 230 Vac.
UPS AC Output Voltage
Cable Minimum Wire Size
115 Vac
#10AWG (6mm
2
)
230 Vac
#12AWG (4mm
2
)
The “neutral” wire of the 3-Phase AC OUTPUT should be kept at a potential close to Protective
Earth Ground (PEGND).
When ordering, select the “F: Floating” option for UPS units configured in this manner.
Contact the factory for N+1 redundant 3-phase systems.
Note: The three connectors of the SYN-9317 CONFIGURATION CABLE are labeled “Line 1”, “Line
2” and “Line 3”. The UPS unit that receives the “Line 1” connector will have an AC OUTPUT that is
phased 120 degrees (one-third cycle) ahead of the UPS unit that receives the “Line 2” connector,
which in turn will have an AC OUTPUT that is phased 120 degrees (one-third cycle) ahead of the
UPS unit that receives the “Line 3” connector. Connecting the three AC OUTPUTs to the three
line wires of the AC OUTPUT cable in the proper order may be important for some loads, such
as motors.
