Signal cable electromagnetic interference

Current-carrying AC cables set up an electromagnetic field, and that field can couple interference into nearby network cables while they carry data. Signal and communication cables pick up disturbance from three-phase power cables and from strong emitters such as frequency inverters, drives, motors, transformers, fluorescent lights and wireless transmitters. The results are communication problems, data transmission errors and measurement errors on analog signals. Do not pull communication cables through the same conduit as high-voltage conductors. Keep them apart from power cables: at least 12 inches in conduit and 18 inches in cable tray. Where they must cross power cables, cross at a sharp 90 degree angle instead of running alongside. Twisted-pair, shielded cable reduces the interference picked up. Running the cable in its own metal conduit protects it further. Connect the cable shield to the ground point, and ground the equipment housings properly. This improves resistance to interference and the quality of communication. If radio interference is reported, measure noise levels at different distances from the inverter, the AC and DC cabling and the communication cables to find the source.

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• sentence 3: support check: partial - Passages mention measurement errors, data transmission errors and communication issues, but the analog-signal measurement errors are only implied and the causal link to these sources is loose. -->