At the same time, it is suggested that armored bus cable should be used instead of non-armored bus cable for Pprofibus-DP cable in outdoor lightning protection.
-Extended reading.
Frequency converter, power cable, transformer, high-power motor, etc. It is often accompanied by low frequency interference, which can not be solved by cables with high conductivity materials as shielding layers, including imported cables. Only the shielding layer made of high magnetic permeability materials (such as steel strip and steel wire) can effectively suppress low frequency interference.
The most common method is to use high permeability material (patent number: 201020559128.9)-astp-120ω (for RS485 &；; CAN) A pair of 18 AWG, with an outer diameter of about 12.3mm, can be used in places with serious interference, frequent rodent damage and lightning protection and explosion protection requirements. When in use, it is recommended that both ends of the armor layer are grounded, and one end of the innermost shielding layer is grounded!
Lightning protection of outdoor cables is very important! The equivalent interference frequency of lightning is about 100k, which also belongs to low-frequency interference.
Article 6.3. 1 of Code for Lightning Protection Design of Buildings (GB50057-94): ...... In the protected space, when shielded cables are used, the shielding layer should be at least equipotentially connected at the junction of both ends and the lightning protection area. When the system only requires equipotential connection at one end, two layers of shielding should be adopted, and the outer shielding should be treated according to the above requirements.
GB 502 17-2007 Code for Cable Design has a similar statement. Search for "Industrial Automation Series Integrated Cable Solution".