9 ac and dc connection, 1 safety during cable connection, 2 connection options – SMA SC 500HE-20 Installation User Manual
Page 36: Ac and dc connection, Safety during cable connection, Connection options
9 AC and DC Connection
SMA Solar Technology AG
36
SCxxxHE-20-IA-IEN111210
Installation Manual
9 AC and DC Connection
9.1 Safety during Cable Connection
Risk of fire
Too low ampacity of the connection cables leads to strong heating.
The connection cables must have sufficient ampacity. The ampacity depends on the following
conditions:
• Cable cross-section
• Cable type
• Routing method
• Ambient conditions
• Only use aluminum cables or copper cables.
Inadequate connections and oxidized contact surfaces cause excessive heating.
Tin-plated copper rails are standardly provided in the inverter for the connection of copper or
aluminum cables.
• Only use the nuts, screws and washers provided in the scope of delivery for the connection.
• Only use tin-plated crimp-type terminal lugs.
• Always connect 2-hole terminal lugs with 2 screws.
• Before connecting the cables, clean the contact surfaces (see section 9.4.2).
• Do not touch the contact surfaces after cleaning.
Non-observed torques cause strong heating.
To ensure the required ampacity at the connection points, all torques specified in this document must
be observed.
• For connections of tin-plated aluminum terminal lugs, observe a torque of 37 Nm.
• For connections of tin-plated copper terminal lugs, observe a torque of 60 Nm.
9.2 Connection Options
DC Fuses or DC Busbar
Depending on the order option, the inverter will be equipped with either DC fuses or DC busbars.
Each terminal lug can be assigned with 1 or 2 cables.
You can connect 1-hole or 2-hole terminal lugs to the DC fuses.
You can only connect 1-hole terminal lugs to the DC busbar.