5 Connection
SMA Solar Technology AG
14
485i-Module-IA-en-19
Installation Manual
5.3 Connecting the 485 Data Module
To achieve a good signal quality, observe the cable recommendation (see Technical Description
"RS485 Cabling Plan").
Procedure:
To connect the 485 Data Module, perform the following work steps in the prescribed sequence.
The exact procedure is described in the following sections.
• Prepare the cable
• Connect the cable to the 485 Data Module
Preparing the Cable
1. Remove 40 mm of the cable sheath at the end of the cable which is to be connected to the
485 Data Module.
2. Shorten the cable shield to 15 mm.
3. Fold the surplus cable shield back over the cable
sheath.
4. Wrap the cable shield in conductive adhesive foil.
5. Strip off the insulation of the three insulated conductors by 6 mm. The two insulated conductors
used for communication must be a twisted pair.
6. Shorten all other conductors flush with the cable sheath.
Interference in data transmission due to AC cables
During operation, AC cables generate an electromagnetic field which may induce interference
in plant communication.
• Lay the RS485 communication cables using suitable fastening material and with a
minimum clearance of 50 mm to the AC cables.