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8. APPENDIX A : UPS Installation for Parallel System
(part numbers with parallel option only)
8-1. Paralleling UPS Devices
Make sure all of the UPSs are parallel models.
A maximum of three Sinergy III UPSs can be connected in parallel. The units to be connected in parallel must be
of the same type and rating and the settings of these devices must be identical.
Before connecting the parallel cable(s) and the current share cable(s) between the UPSs in the parallel system
make sure that each UPS has the same configuration, including the following parameters:
a) output voltage
b) output frequency
c) bypass voltage range
d) bypass frequency range
e) converter enable or disable
f) bypass enable or disable
g) bypass open or forbidden
h) frequency auto detect enable or disable
i) inverter short clear enable or disable
8-2. Output voltage calibration
Before connecting the parallel cable(s) and the share current cable(s) between the UPSs in the parallel system,
turn on each UPS into the line mode or into the battery mode respectively. Using a multimeter measure the output
voltage of each UPS. Make sure that the difference in the output voltage amoung the UPSs is less than 1.0V. If
not the output voltage can be adjusted from the front panel LCD as shown below.
After adjusting the inverter voltage, confirm that the difference between the displayed value and the voltage meas-
ured by a multimeter is no more than 1V. If the voltage difference is more than 1V, please adjust the output volt-
age via the LCD so that the difference is not more than 1V. Then, shut down the UPS to save this setting into
EEPROM.