IV404E Rev.000 SIEL S.p.A.
Issue date: 2017-06-05 Pag. 18 di 90 + FR
3.1.2 Selectivity
The system where the UPS is
inserted must be set up in such
a way that in the event of a
shortcircuit on one of the lines
downstream of the UPS, the
fuse on the output opens while
the upstream fuse normally
works. This is known as
selectivity, and ensures that the
remaining feeders maintain the
power supply.
In order to select the correct protection devices to be inserted downstream of the SAFEPOWER EVO HFT,
the following two operating modes have to be taken into consideration:
mains power supply
and
battery
power supply
.
With
mains power supply
the output fuse must be selective with the input fuse; the condition is verified
for the following values:
[kVA]
300
400
500
600
Rated output current:
[A]
433
578
722
867
Type gG fuse used at the UPS input
(as shown in the
table of connections
)
[A]
500
630
800
1000
Maximum fuse at the UPS output for selectivity:
Fuse size for type gG fuse
[A]
315
400
500
630
Fuse size for type aM fuse
[A]
200
250
315
400
At least two feeders are necessary in order to use the UPS at rated load with fuses of type gG.
H
+/-
L
O
A
D
UPS
SWBY
SWIN
SWOUT
+/-
BATTERY CABINET
