4. Operation
4.5.2 Turning On a Parallel System in On-line Mode
1) Turn on the line input breaker of each UPS, then turn on the external main input breaker. When all UPS systems enter Bypass Mode,
measure the output voltage between two UPS systems for the same phase to ensure the phase sequence is correct. If these two
voltage differences are near zero, then all connections are correct. If not, check to see if the wirings are connected correctly.
2) Turn on the output breaker of each UPS.
3) Turn on each UPS one at a time. The UPS systems will then enter On-line Mode synchronously. The parallel system is completed.
4.5.3 Turning On the Parallel System in Battery Mode
1) Turn ON the battery breaker and output breaker of each UPS.
Note: UPS may share the same battery bank or use separate battery banks while in a parallel system.
2) Turn on any UPS. A few seconds later, the UPS will enter Battery Mode.
3) Turn on another UPS. A few seconds later, the UPS will enter Battery Mode and add to the parallel system.
4) If there is a third UPS in the setup, follow the same procedure as outlined above. The parallel system is complete.
4.5.4 Adding a New Unit to the Parallel System
1) A new unit cannot be added to the parallel system when the whole system is in operation. The load must be powered off and the UPS
system shut down.
2) Make sure all UPS systems can be connected in parallel. Follow the wiring instructions in section 3.4.
4.5.5 Removing a Unit from the Parallel System
There are two methods to remove a unit from the parallel system:
Method 1:
1) Press the "OFF" key twice, each time for more than 0.5 seconds. The UPS will enter into Bypass Mode or Standby Mode without
output.
2) Turn off the unit's output breaker and input breaker.
3) After the unit shuts down, turn off the battery breaker and remove the parallel cable and shared current cables. Remove the unit from
the parallel system.
Method 2:
1) If the UPS indicates a bypass abnormal error code, you cannot remove the UPS without interruption and must first power down the
load and the UPS system.
2) Make sure the bypass setting is enabled in each UPS, then turn off the running system. All UPS systems will transfer to Bypass Mode.
Remove all the maintenance bypass covers and set the maintenance switches from "UPS" to "BPS". Turn off all input breakers and
battery breakers in the parallel system.
3) Turn off the output breaker and remove the parallel cable and shared current cable of the UPS to be removed. Remove the unit from
the parallel system.
4) Turn on the input breaker of the remaining UPS system(s), then turn on the external main input breaker. The system(s) will transfer to
Bypass Mode. Set the maintenance switches from "BPS" to "UPS" and reattach the maintenance bypass covers.
5) Turn on the remaining UPS systems.
Warning: (for Parallel System Setups Only)
• Before turning on the parallel system to activate the inverter, make sure all UPS maintenance switches are set to the
same position.
• When the parallel system is turned on to work through the inverter, do not operate the maintenance switch of any
unit.
• The parallel system DOES NOT support ECO Mode. DO NOT enable ECO Mode in any unit.
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