Siemens SIWAREX FTA Device Manual page 34

Hardware Planning and Assembly
The following rules are to be followed when connecting load cells (WZ).
Using a junction box is required if more than one LC is connected (the LC must be
connected parallel to one-another).
If the distance from LC to SIWAREX FTA is greater than the existing length of the
LC connection cable then the extension box EB is to be used.
2. The cable shielding is normally run on the cable guide supports of the junction box.
In case of the danger of potential equalisation currents on the cable shielding,
a potential equalisation conductor is to be run parallel to the load cell cable or the
shield clamp is to be used in the junction box to the shield strip. Using the potential
equalisation conductor is the preferred method of dealing with EMC
(Electromagnetic Compatibility).
Image 4-4 Shielding in the screw joint
3. Twisted pair cable is required for the indicated wiring:
- Sensor lines (+) and (-)
- Measurement voltage lines (+) and (-)
- Supply voltage lines (+) and (-)
4-22
SIWAREX FTA