Criteria For The Proper Selection Of String Fuses; General; Effects Of Using Underrated Fuses; Fuse Recommendations - Application Example - Fronius String Control 250/25 Operating Instructions Manual

Criteria for the Proper Selection of String Fuses

General

The use of string fuses in the Fronius String Control 250/25 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
Criteria for the The following criteria must be fulfilled for each solar module string when
Proper Selec- using fuse protection:
tion of String -
Fuses -
-
-
I
I
V
Effects of With underrated fuses, the nominal current rating of the fuse is less than
Using Under- the short circuit current of the solar module.
rated Fuses Effect:
The fuse may blow under intensive irradiance conditions.
Fuse Recom-
mendations -
Application
Example You should only use the following fuses, which have been tested by Froni-
us, to ensure problem-free fuse protection:
-
-
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.
I > 1.5 x I
N SC
I < 2.00 x I
N SC
V >/= max. input voltage of inverter being used:
N
FRONIUS CL 36.0 / 48.0 / 60.0 ........... 600 V DC
FRONIUS IG 300 / 390 / 400 / 500 ..... 530 V DC
Fuse dimensions: Diameter 10 x 38 mm
......... Nominal current rating of fuse
N
....... Short circuit current for standard test conditions (STC) according
SC
to solar module data sheet
....... Nominal voltage rating of fuse
N
NOTE Only select fuses whose nominal voltage is higher or
equal to the max. input voltage of the inverter being used.
Littelfuse KLKD fuses
Cooper Bussmann PV fuses
of the respective solar module.
SC
18