Electrical Connection
SMA America, LLC
38
SB8-10TL-IUS103811
Installation Guide
6.6.1 DC connection requirements
Cable sizing
All electrical installations must be done in accordance with all local electrical codes and with the
National Electrical Code
®
, ANSI/NFPA 70. For installation in Canada the installations must be done
in accordance with applicable Canadian standards.
When selecting the type and cross-section of the cable in accordance with the routing method,
observe the following requirements:
• For all DC wiring connections to the string combiner box use 10 … 6 AWG (6 … 16 mm²),
194 °F (90 °C) rated copper wire (
National Electrical Code
®
690.35).
• For DC wiring connection between the string combiner box and the inverter use min. 8 AWG
(10 mm²), 194 °F (90 °C) rated copper wire (
National Electrical Code
®
310.16).
• Use only solid or stranded wire but not fine stranded wire.
6.6.2 Connecting the DC cable
1. Lay a cable conduit from the Sunny Boy Combiner Box to the SMA DC Disconnect (see chapter
6.3 ”Insert the cable into the SMA DC Disconnect” (page 29)).
2. Follow all safety instructions of the PV module manufacturer.
3. Open the SMA DC Disconnect as described in section 8.3 ”Opening SMA DC Disconnect”
4. Lead the AC cable through the cable conduit into the inside of the SMA DC Disconnect.
Use the free design programs "Solar Design Tools" at www.SMA-America.com to
determine the correct string configuration.
DANGER
High voltage is present inside the DC cables.
Death or serious injury will result when damaging a DC cable or touching a DC conductor.
• You have to connect the DC cables from the PV array to the Sunny Boy in the order
described in this manual.
DANGER
High voltage is present in PV modules exposed to light.
Death due to electric shock when touching a DC conductor.
• During installation, cover the PV modules with opaque material.
