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[802.3BA] Standards for immunity of shielded copper links to power-frequency ground loops

First the background: 

In some ethernet applications, the primary source of interference comes 
from different ground voltages in different parts of the facility, such as 
a ship or a megawatt radar. 

The effect of differing ground potentials on a copper enet link is to pull 
a large current through the shield, so there is a significant voltage 
between the ends of the link.  No matter how good the shield is at RF, one 
consequence is that the same power-frequency offset voltage appears on the 
conductors within that shield, because the skin depth at 60 Hz vastly 
exceeds the thickness of any reasonable shield.  Unshielded twisted pair 
will suffer the same offset voltage, perhaps more.   This offset often 
contains significant harmonics of the power frequency, up to the seventh 
harmonic, not just the fundamental.

If the cable is (shielded) twisted pair, the offset appears as a 
common-mode voltage on the two conductors, and (if not too large) is 
eliminated by the CMRR of the receiver. 

If the cable is coax, the offset voltage appears added to the signal 
voltage, and if the offset isn't too large the link still functions. 

(If the cable is fiber, no problem, but that is not the question here. 
While fiber is used wherevere possible, there are always some copper 

And now the question: 

What standards exist governing required immunity of signal ports to these 
ground-loop induced voltages?

All the conducted suseptability standards I've found cover only 
frequencies exceeding 10 KHz, not power frequencies and their harmonics.


Joe Gwinn