Riello UPS CSS SENTINEL TOWER CAM 3, Installation And User Manual

Page: 17 / 40

- 15 -
I
NTERNAL
P
ROTECTION
Within the cabinet there are fuses (not accessible) in order to protect the rectifier input stage, the output stage of the inverter
and the batteries. The table below shows the values of the internal protection fuses.
NOTE: the CPS internal bypass line is not protected by fuses. We recommend installing an external protection device as
defined in the chapter
“E
XTERNAL
P
ROTECTION DEVICES
” .
Internal protective devices
Model Input fuses Battery fuses Output fuses
3 kVA 2 x 25A GF (6.3x32) 80A aR 2 x 25A GF (6.3x32)
5 kVA 2 x 25A GF (6.3x32) 80A aR 2 x 25A GF (6.3x32)
WARNING: To insulate the CPS from the D.C. supply, disconnect all of the Battery Cabinets (if present).
SHORT CIRCUIT
If a fault occurs on the load, the CPS protects itself by limiting the value and the duration of the current supplied (short circuit
current). The short circuit current value is related to the CPS operating status at the time of the fault, these can either be (in
the "
T
ECHNICAL
D
ATA
” table the protection characteristics and timings are described):
 CPS in NORMAL OPERATION with the Bypass Line available: the load is switched instantaneously to the bypass
line: the input line is connected to the output without any internal protection.
 CPS in BATTERY OPERATION or in NORMAL OPERATION but with no Bypass Line available: the CPS protects
itself by providing a higher current than the nominal one (see paragraph “
T
ECHNICAL
D
ATA
”) and turns itself off after
this time has elapsed.
NOTE FOR SELECTIVITY: if the load is made up of more than one device, to avoid the opening of the protective devices
upstream of the CPS due to a failure of a single piece of equipment, it is recommended to protect each output line with a
suitably rated thermal or magnetothermal protection device. The maximum value for the protective device of each single line
must be lower than the current threshold of the protection upstream of the CPS and lower than the current supplied by the CPS
with the inverter on.
BACKFEED
The CPS has internal protection against backfeed, however the label supplied with the CPS must be affixed to all disconnectors
installed within the electrical system upstream of the CPS.