Operation

8.1.3Output Off Mode

To transfer the paralleling system to Output Off Mode:

1.Make sure that each UPS is in Bypass Mode.

If a UPS is not in Bypass Mode, press the UPS’ Off button once (see 8.1.2 - Bypass Mode).

2.Press the Off button on the first UPS twice within four seconds.

3.Perform Step 2 on each UPS in the paralleling system within one minute, otherwise the paralleling system cannot enter Output Off Mode.

4.Each UPS will transfer to Output Off Mode synchronously.

NOTE

If one of the UPSs in the paralleling system is not in Bypass Mode, press the Off button on the UPS that is not in Bypass Mode twice to immediately shut down only that UPS.

8.2Fault Condition

If one UPS in the paralleling system fails due to either of the following two conditions, the other UPSs in the paralleling system will remain in Bypass Mode.

UPS has a soft-start fault (LED E on the UPS control panel illuminates).

The internal battery in the UPS is disconnected or the battery voltage is less than 200V (LED A and LED C on the UPS control panel illuminate).

Once the fault is cleared, see 8.5 - Add a Single UPS to the Online Paralleling System to rein- stall the UPS in the paralleling system.

8.3Battery Test

To initiate a manual battery test, execute the “Manual Battery Test” command from the UPS control panel or RS-232 port. For the battery test to proceed, the UPS battery capacity must be 90 percent or greater. If capacity is less than 90 percent, the battery test will be aborted.

If battery failure is detected during the test, the test will be aborted, the UPS will return to Line Mode and LEDs A and C on the front panel will illuminate.

To stop the battery test manually, press the Off button for at least one second or execute the “Cancel Battery Test” command via the RS-232 port. The test stops and the UPS returns to Line Mode.

8.4Parallel Communication Cable Disconnection

There is only one master UPS in a paralleling system; the other UPSs operate as slaves. If one paral- lel communication cable disconnects from the paralleling system, the UPS will detect this fault and transfer to Output Off Mode with alarm. The UPS must be shut down to clear this fault.

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Emerson GXT2-PP20KRT208 user manual Fault Condition, Battery Test, Parallel Communication Cable Disconnection