Ups Shutdown; Parallel Ups System - ABB PowerValue 11/31 T Operating Manual

5.3.2

UPS Shutdown

With mains supply
1. If the UPS is working on bypass-mode, go to step 3.
2. If the UPS is on online-mode, press the power-on button continuously for more than 3s. The alarm
buzzer will sound and the UPS will transfer to bypass-mode. Note: the output is still energized.
3. Disconnect the UPS from the mains power supply through the output breaker. A few seconds later
the display will shut down and the output voltage will be removed from the UPS output terminal.
In case the bypass has been disabled through the Settings menu, press the power-on button for more
than 3s to shutdown the UPS. The unit will change from online to stand-by-mode. Then, simply
disconnect the input power cable and a few seconds later the display will shutdown.
Without mains supply
1. To power off the UPS, press the power on/off button continuously for more than 3s. The alarm
buzzer will sound for 3s and the output power will be immediately cut-off.
2. After a few seconds, the display will shut down and the output voltage will be removed from the
UPS output terminal.
5.3.3

Parallel UPS system

Installing a new parallel system
1. Do not switch on the output breaker of each UPS. Switch on the input breaker of the each UPS
and the UPS will transfer to bypass.
2. Observe the UPS displays to check if there are warnings or fault information. Measure the output
voltage of each UPS separately to check if the voltage difference between them is lower than 1V. If
the difference is higher than 1V, check the wiring.
3. Press the power-on button of one UPS. Each UPS will start up and all of them will transfer to the
inverter at the same time.
4. Measure the output voltage of each UPS separately to check if the voltage difference between them
is lower than 0.5V. If the difference is higher than 1V, the UPSs must be regulated.
5. Press the power-on button of one UPS. Each UPS will transfer to the bypass-mode. Switch on the
output breaker of each UPS to parallel the output of all UPSs at the same time.
6. Press the power-on button of one UPS, each UPS will start up and they will work in parallel in online
mode.
Adding a UPS to an existing system
Read carefully section 5.4 before following the procedure below.
Note: The parallel system must have a main maintenance mechanical switch or static switch according
to Figure 15.
1. Regulate the output voltage of the new UPS separately: check if the output voltage difference
between the new UPS and the parallel system is lower than 0.5V.
2. Ensure that the bypass of the parallel system is working and the bypass setting is "enabled".
3. Remove the cover plate of the maintenance switch on the rear panel of each UPS. The UPS system
will transfer to bypass automatically.
Modifications reserved
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