13
4) Turn on the input breakers of all UPSs in the parallel systems and turn on each UPS in turns. Make
sure that AC mode LED or Battery mode LED displays in each UPS. Measure the output voltage of
each UPS to check if the voltage difference is less than 2V (typical 1V) with multimeter. If the
difference is more than 2V, please check that parallel cable or share current cable are connected well.
If they are all connected well, maybe it’s UPS internal issue. Please contact your local distributor or
service center for help.
5) Turn off each UPS in turns and after all of them transfer to Bypass mode, turn on the output breaker of
each unit.
6) Turn on the UPSs in the AC mode and then the parallel system connection is complete.
2. Add one new unit into the parallel system
1) You can not 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, and follow the wiring refer to section 2-3.
3) Install the new parallel system refers to the previous section.
3. Remove one unit from the parallel system
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.
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 the input breakers and battery breakers.
3) Remove the UPS that you want.
4) Turn on the input breaker of the remaining UPSs and the system will transfer to Bypass mode.
5)
Set the maintenance switches from “BPS” to “UPS and put the maintenance bypass covers back. Turn
on the remaining UPSs and finish the parallel system connection.
Warning:
(Only for the parallel system)
● Before turning on the parallel system to activate inverter, make sure that all unit’s maintenance switch at
the same position.
● When parallel system is turned on to work through inverter, please do not operate the maintenance
switch of any unit.
