Fronius IG Plus 3.0-1 User Manual

53
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
> 1.56 x I
SC
-I
N
< 2.00 x I
SC
-V
N
>/= 600 V DC
- Fuse dimensions: Diameter 10.3 x 35 - 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 string fuse size must not be greater than the maxi-
mum fuse size rating of the PV module as provided on the PV
module manufacturers data sheet. If no maximum fuse size is
indicated, please contact the PV module manufacturer.
Effects of
using underra-
ted fuses
In underrated fuses, the nominal current value is less than the short circuit
current of the solar module.
Effect:
The fuse may trip in intensive irradiance conditions.
General The use of string fuses in the inverter 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.
DC disconnect
requirements
NEC 690.15-18 allows the use of fuse holders as a suitable means of
disconnecting PV arrays for servicing. Additional DC disconnects external
to the inverter may be required by the local authority having jurisdiction.

Fronius IG Plus 3.0-1 Specifications

General

Protection class	IP 44
Max. output current	13 A
Nominal AC voltage	230 V
THD	< 3%
Max. DC voltage	500 V
Maximum Input Voltage	500 V
Number of MPP Trackers	1
Operating Temperature Range	-20°C to +55°C
Cooling	Convection
Warranty	5 years
AC nominal output	3000 W
Max. apparent AC power	3000 VA
AC voltage range	180 - 264 V