SMA RS485-Quick Module - Manual (Page 20)

Assembly SMA America, LLC
20 RS485-QM-IA-eng-IUS111610 Installation Guide
5.2 Connecting the RS485-Quick Module to the RS485 bus
5.2.1 Cable Requirements
The cable length and quality have an effect on the signal quality.
The cable must fulfill the following requirements to guarantee a good signal quality:
• Use cables of type 600V LVLE.
• Diameter of the cable:
15
⁄
64
in. (6 mm) to
17
⁄
64
in. (7 mm).
• Cross-section of the conductors: At least 2 x 2 x AWG 24 (2 x 2 x 0.22 mm²).
• Conductors must be made up of twisted wire pairs.
• The cable must be shielded and double insulated.
• For outdoor use only: the cable must be UV resistant.
You can order suitable cables from SMA.
Purchase order numbers:
• For outdoor use: COMCAB-OUTxxx*
*Available in the lengths xxx = 100 (100 m / 328 ft.); xxx = 200 (200 m / 656 ft.); xxx = 500 (500 m / 1 640 ft.) and
xxx = 1 000 (1 000 m / 3 280 ft.)
5.3 Preparing the cable
1. Ensure that the RS485 cable is long enough.
2. Shorten the cable sheath and cable shield by 1
1
⁄
2
in. (40 mm) (A).
Length of the cable
When the cable has been connected, you must push the RS485-Quick Module approx.
8 in. (200 mm) upwards. Note that the cable has to be long enough to reach the end
position of the RS485-Quick Module.
Preparing the cable
Carry out the following steps outside the RS485-Quick Module, to ensure that no metal
residues of the shield or the cable fall into the RS485-Quick Module.