2
Connecting Solar Module Strings to the Fronius IG Plus (DC) ........................................ 27
General Information About Solar Modules ................................................................... 27
Safety........................................................................................................................... 27
DC-Terminals ............................................................................................................... 28
Connecting Aluminum Cables ...................................................................................... 28
Overview ...................................................................................................................... 29
Ungrounded System: Connecting Solar Module Strings .................................................. 30
Cable Cross Section of Solar Module Strings .............................................................. 30
Ungrounded System: Connecting Solar Module Strings.............................................. 30
Selecting String Fuses ................................................................................................. 32
Using String Fuses in Fronius IG Plus ......................................................................... 32
Criteria for the Proper Selection of String Fuses.............................................................. 33
General ........................................................................................................................ 33
Criteria for the Proper Selection of String Fuses ......................................................... 33
Effects of using underrated fuses ................................................................................ 33
Fuse Recommendations - Application Example .......................................................... 33
Fuses ...........................................................................................................................34
Ungrounded System: Connecting Solar Module Strings with a Cable Cross Section > 16
mm² .................................................................................................................................. 35
General ........................................................................................................................ 35
Additional Required Components ................................................................................ 35
Ungrounded System: Connecting Solar Module Strings with a Cable Cross Section >
16 mm²......................................................................................................................... 35
Solar Module Ground at Negative Pole: Connecting Solar Module Strings ..................... 38
General ........................................................................................................................ 38
Cable Cross Section of Solar Module Strings .............................................................. 38
Solar Module Ground at Negative Pole: Connecting Solar Module Strings ................. 38
Selecting String Fuses ................................................................................................. 40
Using String Fuses in Fronius IG Plus ......................................................................... 40
Criteria for the Proper Selection of String Fuses.............................................................. 41
General ........................................................................................................................ 41
Criteria for the Proper Selection of String Fuses ......................................................... 41
Effects of using underrated fuses ................................................................................ 41
Fuse Recommendations - Application Example .......................................................... 41
Fuses ...........................................................................................................................42
Solar Module Ground at Negative Pole: Connecting Solar Module Strings with a Cable
Cross Section > 16 mm² .................................................................................................. 43
General ........................................................................................................................ 43
Additional Required Components ................................................................................ 43
Solar Module Ground at Negative Pole: Connecting Solar Module Strings with a Cable
Cross Section > 16 mm² .............................................................................................. 44
Solar Module Ground at Negative Pole: Connecting Solar Module Strings with a Cable
Cross Section > 16 mm² .............................................................................................. 45
Solar Module Ground at Negative Pole for Fronius IG Plus............................................. 47
General ........................................................................................................................ 47
Solar Module Ground at Negative Pole ....................................................................... 47
Solar Module Ground at Negative Pole for Fronius IG Plus ........................................ 47
Safety........................................................................................................................... 48
Setting Inverters for Grounded Solar Modules............................................................. 48
Solar Module Ground: Inserting Fuses ........................................................................ 48
Opening Fronius IG Plus for Service/Maintenance ...................................................... 49