Separate A Ups Unit From The Redundant Parallel System - GE 8 Series Operating Manual

8.2.4 Separate a UPS unit from the Redundant Parallel System

INITIAL SITUATION:
The load is powered by the UPS Redundant Parallel System.
One UPS unit of the Parallel System has to be turned Off, while the load is shared
between the other units supplying the parallel bus.
WARNING!
The control bus cable connecting J52 (A) and J62 (B) cannot be connected or
disconnected after the system has been powered on.
1. Disconnect the inverter by pressing "Inverter OFF" ( O ) key and hold until the LED Inverter (5)
turns OFF on the Unit to separate.
With redundant system, pressing the key OFF the inverter shuts down and it will stay OFF.
If by pressing the key "O" the load is transferred to the mains and the inverter remains operating, it means
the system is not redundant.
In this case is not possible to switch-OFF one unit without transferring the load on mains.
Load supplied from inverter(s) of the other Unit(s) of the Parallel System.
2. Open the output switch Q1 on the Unit to separate.
LED Alarm is lit and the LED Operation is Off.
3. Perform the command "Load Off" on the Unit to
separate.
Perform the command "Load Off" by entering the
screen (see Section 7.5):
COMMANDS / REQUEST LOAD OFF
The output contactor K6 open.
4. Open the input rectifier switch Q4 (Pos. 0) on the Unit to separate.
The rectifier turns OFF. The acoustical alarm is activated, press "MUTE" key to reset it.
5. Disconnect the battery removing the battery fuses F8 – F9 on the Unit to separate.
The acoustical alarm is activated, press "MUTE" key to reset it.
6. Disconnect the mains, on the Unit to separate, from the input distribution only when the DC-
Link voltage results to be below 20 Vdc (see screen METER / BATTERY / V).
The UPS is now voltage free, except for battery voltage in case the battery is integrated in the UPS cabinet.
All the LEDs and the LCD display must be OFF.
WARNING!
It will take 5 minutes for the DC capacitors to discharge
Open only the front door, do not open any other part of the UPS.
NOTE !
For any further intervention contact nearest Service Centre.
Modifications reserved
OPM_SPE_XXX_10K_40K_8GB_V020.doc
Home\Commands
COMMANDS
RESET LOAD OFF
REQUEST LOAD OFF
Operating Manual SitePro 10-15-20-30-40 kVA / S8
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