Alan Melia wrote: > Hi Tom Brilliant I hadnt thought of the fields actually affecting the > operation of the electronics! that is certainly something that might be > interesting to check. I note there lines have three "phase" feeds but no > neutral wire so they must use ground as the return path to any unbalance > currents.(?)
On the UK 11kV overhead network the phases are all distributed without a neutral. At the 11kV/415V transformer the HV side is delta wound and the LV is star wound, so the neutral/earth for the supply is taken from that point, not from the HV side. So, you are correct, the connection to "the general mass of earth" at the transformers is used as the return path. Which is why there are regulations about the acceptable earthing impedances at HV/LV transformers on an overhead supply. Tales of Linesmen watering earth rods to get away without having to drive in more earth rods and connect up to the transformers, and so avoid having to drive rods into hard ground, are legion in the ESI... In fact, if you look at most of the overhead high voltage distribution systems, they are all phase only, no neutral... Dave (G0DJA) _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
