SMA STP 8000TL-10 - Manual (Page 36)

6 Electrical Connection SMA Solar Technology AG
36 STP8-17TL-IA-en-31 Installation Manual
Function of the electronic string fuse
The electronic string fuse prevents reverse currents in the PV array. Activation of the electronic string
fuse is only possible if the following conditions are met:
• During installation, the DC input voltage must be at least 188 V (see Section 14 "Technical
Data", page 95) in order to activate the protective function of the integrated electronic string
fuse. Otherwise, a reversed polarity at the DC connection or a defective string will not be
recognized by the inverter.
Risk of fire in the PV array due to non-recognition of reverse currents
The integrated electronic string fuse monitors the PV array and protects it against dangerous reverse
currents. In order to activate the electronic string fuse, you must observe the following during
connection of the strings:
• If more than 2 strings are connected to the inverter, ALWAYS connect the first string to
input B. If no string is connected at input B, the string fuse will not be active.
• Each string must be clearly assigned to the correct string input. Do not cross-wire or bundle the
string cables. See the diagram in Section 6.4.1 for the correct assignment of the strings.
Use of external string collection boxes
If string collection boxes are used, the functionality of the electronic string fuse may be limited.