Xtreme Power Conversion Corporation
NXTi 3P-3P User’s Manual
Page 15
Uninterruptible Power Supply
2.
Calibrate the output voltage measurement by configuring output voltage calibration in LCD setting to make
sure the difference between real output voltage and detected value of UPS is less than 1V.
3. Turn off each UPS.
4. Remove the cover of parallel share current cable port on the UPS, connect each UPS one by one with the
parallel cable and share current cable, and then screw the cover back.
5. Turn on the parallel system 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. Turn on the output breaker of each UPS.
c.
Turn on each UPS in turns. After a while, the UPSs will enter to AC mode synchronously and then,
the parallel system is completed.
6. Turn on the parallel system in Battery mode
a.
Turn on the battery breaker (only available in long-run model) and output breaker of each UPS.
NOTE:
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.
If more detailed information is needed, please contact supplier or service center for parallel operation instruc
-
tion.
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.
3. After it shuts down, you can turn off the battery breaker (for long-run model) and remove the parallel and
share current cables. And then remove the unit from the parallel system.
Second method:
1.
If the bypass is abnormal, you can not remove the UPS without interruption. You must cut off the load and
shut down the system first.
2.
Make sure the bypass setting is enabled in each UPS and then turn off the running system. All UPSs will
transfer to Bypass mode. Remove all the maintenance bypass covers and set the maintenance switches
from “UPS” to “BPS”. Turn off all the input breakers and battery breakers in parallel system.
3. Turn off the output breaker and remove the parallel cable and share current cable of the UPS which you
want to remove. Then, remove it from parallel system.
4. Turn on the input breaker of the remaining UPS and the system will transfer to Bypass mode. Set the main-
tenance switches from “BPS” to “UPS and put the maintenance bypass covers back.
5.
Turn on the remaining UPS according to the previous section.
