Fronius String Control 250/25 DCD DF - Manual (Page 77)

19
EN-US
Criteria for the Proper Selection of String Fuses
Criteria for the
Proper Selec-
tion of String
Fuses The following criteria must be fulfilled for each solar module string when
using fuse protection:
-
I
N
> 1.8 x I
SC
- I
N
< 2.4 x I
SC
- V
N
>/= max. input voltage of inverter being used:
FRONIUS CL 36.0 / 48.0 / 60.0 ........... 600 V DC
- Fuse dimensions: Diameter 10 x 38 mm
I
N
......... Nominal current rating of fuse
I
SC
....... Short circuit current for standard test conditions (STC) according
to solar module data sheet
V
N
....... Nominal voltage rating of fuse
NOTE The nominal current value of the fuse must not exceed the
maximum fuse protection value specified in the solar module
manufacturer’s datasheet. If a maximum fuse protection value is
not specified, please request it from the solar module manufactu-
rer.
Effects of
Using Under-
rated Fuses If a fuse is underrated, the nominal current value of the fuse can be less
than the short circuit current of the solar module.
Effect:
The fuse may blow under intensive lighting conditions.
Fuse Recom-
mendations NOTE Only select fuses whose nominal voltage is higher or
equal to the max. input voltage of the inverter being used.
You should only use the following fuses, which have been tested by Froni-
us, to ensure problem-free fuse protection:
-
Littelfuse KLKD fuses
Fronius shall not be liable for any damage or other incidents resulting
from the use of other fuses. In addition, all warranty claims are forfeited.
General The use of string fuses in the Fronius String Control 250/25 DCD DF also
adds fuse protection to the solar modules.
A crucial factor for the fuse protection of solar modules is the maximum
short circuit current I
SC
of the respective solar module.