Pag. 48 / 57 0MNLIBRAPROK10NPENUA 01
4.7
By-pass for maintenance
observe the following precautions when operating SWMB
SWMB must not be closed on a UPS that is off and that is connected in parallel with other units operating
normally. This operation may cause a fault on the UPSs which may create a dangerous voltage at the
output. SWMB may be closed with the LIBRAPRO operating by following the procedure described in the
section “Operating modes” .
operation not to be executed
If disconnector SWMB is closed on any unit, the whole system switches onto by-pass.
If all the switches are then opened to allow maintenance operations to be carried out, all the power required
by the load will switch onto the maintenance by-pass line of the unit in which SWMB has been closed.
WARNING: both the automatic and the maintenance by-pass line of each UPS is sized for the rated
power of the single unit.
N.B. To carry out maintenance on all the UPS, the switches SWMB of all the units must be closed.
maintenance on a single unit
This is the procedure to carry out maintenance operations
on a single unit
(e.g. UPS1):
open switches SWBY, SWOUT, SWIN and the battery cabinet disconnector on unit 1 only.
If the active UPSs can power the load, the system remains in normal operation, and the maintenance can be carried
out on UPS1.
maintenance on the whole system
The sequences of operations to be carried out to place the system in maintenance bypass are described below. The
procedures vary depending on the initial state:
- All the UPS are in NORMAL OPERATION
procedure a)
the power supply to the load is not interrupted in any way
;
- whole system with output not synchronised with the by-pass line
procedure b)
the power supply to the load is interrupted
(therefore this operation should be effected only if absolutely necessary).
Procedure a)
the by-pass line is present and its frequency and voltage are suitable
the UPS display panel
indicates
NORMAL OPERATION.
1.
Pressing keys 3, 6, 4, 7, 2, 6, 3 in succession as shown on the display activates the command for by-
pass with shutdown of the inverter (the UPSs connected to the one in which the code is inserted will be
automatically configured through the parallel cable);
2.
check that the whole system switches onto the by-pass line;
3.
close all the disconnectors SWMB;
4.
open all the switches on the device (SWIN, SWOUT, SWBY and the battery cabinet
disconnectors/fuses) and keep only disconnectors SWMB (maintenance by-pass line) closed. The
control panel remains off.
N.B.: After carrying out the operations indicated above, personnel must wait around ten minutes for the
capacitors to discharge before working on the inside of the LIBRAPRO.
In this situation (during the maintenance operations), any disturbance (such as a blackout) on the UPS
supply line would have an effect on the equipment powered (since the batteries are deactivated in this state).
Summary of Contents for LibraPro
Page 2: ...Pag 2 57 0MNLIBRAPROK10NPENUA 01...
Page 6: ...Pag 6 57 0MNLIBRAPROK10NPENUA 01 This page is left blank intentionally...
Page 25: ...0MNLIBRAPROK10NPENUA 01 Pag 25 57 This page is left blank intentionally...
Page 35: ...0MNLIBRAPROK10NPENUA 01 Pag 35 57 This page is left blank intentionally...
Page 51: ...0MNLIBRAPROK10NPENUA 01 Pag 51 57 This page is left blank intentionally...
Page 53: ...0MNLIBRAPROK10NPENUA 01 Pag 53 57 This page is left blank intentionally...
