On 10/02/19 06:31, Patrick O'Callaghan wrote:
Not being an EE, I haven't the slightest idea. US power company
standards are a closed book to me (I live in the UK where I don't think
this would happen for safety reasons, though I could be wrong). In any
case, Homeplug is a widely supported standards so I suggest asking the
manufacturer.
.
Yes, I have had this problem with remote controlled power devices. Our 120 volt service to the house is derived from a 240 volt line from a center tapped transformer, the center is common and grounded. So we have two possibilities, 180° out of phase. Does the ethenet signal find it's way, maybe, maybe not but I guess I will find out. Some times a different wall outlet will be on the other phase, the other side of the transformer. In that case you would measure 240 volts between the two "high" terminals so it need not be a mystery if there was a problem.

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Bob Goodwin - Zuni, Virginia, USA