Xtreme Power Conversion Corporation
NXTi 3P-1P User’s Manual
Page 15
Uninterruptible Power Supply
5.
Modify the battery pack for the setting number carefully. After complete it, put the cover back, switch on
the battery breaker for long-run model.
Parallel Operation
Parallel system initial startup
1.
Make sure all of the UPSs are parallel models and have the same configuration. Then, follow the wiring
steps.
2.
Turn off the input and output breakers of each UPS, and turn off the battery breaker if the UPS is long-run
model.
3. Remove the cover of parallel share current port on the UPS. Connect each UPS one by one with parallel
cable and share current cable.
4. Turn on the parallel system with utility power supply (in AC mode)
a.
Turn on the input breaker of each UPS. After all UPSs enter to bypass mode, measure the voltage
difference between the output line1 of each UPS with multimeter. If the voltage difference is less
than 1V, it means all connections are correct. If the difference is more than 1V, recheck if the wir-
ings are connected correctly.
b. After voltage difference is measured less than 1V, turn on each UPS in turns. After a while, the
UPSs will enter to AC mode synchronously. Measure the output voltage of each UPS to check if
the voltage difference is less than 1.5V (typical 1V) with multimeter. If the difference is more than
1.5V, please calibrate output voltage by configuring inverter voltage (Program 15) in LCD setting. If
voltage difference remains more than 1.5V, please contact your local distributor or service center
for help.
c.
Turn off each UPS in turns and after all of UPSs transfer to Bypass mode, turn on the output
breaker of each UPS.
d.
Turn on each UPS in turns, after a while, the UPSs will enter to AC mode synchronously and then
the parallel system installation is complete.
5.
Turn on the parallel system without utility power supply (in Battery mode)
a.
Turn on the battery breaker (only available in long-run model) and output breaker of each UPS.
NOTE 1:
The output breaker of each UPS should be turned on when turning on the parallel system
without utility power supply. Otherwise, the parallel system cannot be operated.
NOTE 2:
It’s not allowed to share one battery pack for long-run UPSs in parallel system. Each UPS
should be connected to its battery pack.
b. Turn on any one UPS. A few seconds later, the UPS will enter to battery mode.
c.
Then turn on another UPS. A few seconds later, the UPS will enter to battery mode and add to the
parallel system.
d.
If you have the third UPS, follow the same procedure of c). Then the parallel system is complete.
Add one new unit into the parallel system
1.
You cannot add one new unit into the parallel system when whole system is running. You must cut off the
load and shutdown the system.
2.
Make sure all of the UPS are the parallel models.
3. Install the new parallel system refers to the previous section.
Remove one unit from the parallel system
There are two methods to remove one unit from the parallel system:
First method:
1.
Press the “OFF” key twice and each time should be lasted for more than 0.5s. Then, the UPS will enter into
bypass mode or no output mode without output.
2.
Turn off the output breaker of this unit, and then turn off the input breaker of this unit.
