5 connecting the dc main cables, 1 cable requirements – SMA SSM8-21-BS User Manual
Page 27

SMA Solar Technology AG
6 Electrical Connection
Installation Manual
SSMxx-21-IA-BS-JP-en-20
27
Procedure:
1. Attach the string cables to a cable support rail.
2. Cut the string cables to length and strip off the insulation by 11 mm.
3. If you are using bootlace ferrules, mount the bootlace ferrules and crimp gas-tight.
4. Connect the string cables to the screw terminals of the fuse holders (torque: 2.5 Nm). Ensure correct polarity.
6.5 Connecting the DC Main Cables
6.5.1 Cable Requirements
The Sunny String-Monitor comes supplied with busbars for connecting the DC cables with terminal lugs. If you wish to
connect the DC cables directly to the terminals, the appropriate terminals are available as accessories.
Requirements for DC main cables and terminal lugs:
☐ Use copper or aluminum cables only.
☐ Use only tin-plated copper ring terminal lugs for copper cables or bimetal ring terminal lugs for aluminum cables.
☐ The width of the terminal lug contact surface must exceed the diameter of the washers (32 mm).
Requirements for DC main cables for connection to terminals available as accessories:
☐ Use copper or aluminum cables only.
☐ The conductor cross-sections of the DC main cables must be selected correctly:
/05*$&
Failure of data transmission due to incorrect cable installation
Non-compliance with the minimum clearances between the DC main cables and the data cable may lead to failure of
data transmission. This can result in yield loss.
• When laying the DC main cables, ensure that the minimum clearance of 400 mm to the data cables is observed.
Conductor type
Conductor cross-section
Round, single-strand
25 mm
2
to 150 mm
2
Round, multi-strand
25 mm
2
to 300 mm
2
Sectoral, single-strand
25 mm
2
to 240 mm
2
Sectoral, multi-strand
25 mm
2
to 240 mm
2