Can HV cable create EMI if LV cable near to it?

Simple answer is any current carrying cable can cause EMI in an adjacent cable. The "noisier" the source cable is, the greater the EMI. Too provide a quantitative answer, many factors need to be defined. Say on a 22 kV cable, you would need a lot of harmonics to cause EMI.

First, I would assume this is a 3-phase industrial/utility/marine installation, where you may have cables running in trays, racks, or conduit banks; and the conduit is not ferrous. Threaded rigid steel conduit will have very little EMI, on balanced feeders without ground loops. Code standards should define a minimum spacing between High and Low voltage cables, but this has no bearing if non-ferrous dividers are used as barriers. The closer the spacing, the greater the possible coupling for EMI.

Next, we need to know the type of High Voltage shielding (copper tape, uniwire, etc.) and the cable type and configuration (3 conductor cable, metal clad cable, individual parallel cables, or tri-fold individual cables with rotations). A parallel run of individual phases will have a greater field strength than a three conductor cable. The shielding on HV cables is to maintain a constant zero voltage level on the semiconductor outside the insulation.

Lastly, the configuration of the LV cable is important. If the cable is twisted, this can limit common mode magnetic interference. If there is a metallic jacket or conduit this will shield the conductors from outside interference.


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