SWER (Single-Wire Earth Return)
SWER (Single-Wire Earth Return)
(OP)
Hi,
I've just learned how a SWER system works, but there's still a few things I don't understand. How can you get a decent efficiency with all your current going trough earth?
The ground must be a huge resistance for the current that has to go through many kilometers through ground to come back. It just doesn't make sense to me.
Thanks for your help,
Adam
I've just learned how a SWER system works, but there's still a few things I don't understand. How can you get a decent efficiency with all your current going trough earth?
The ground must be a huge resistance for the current that has to go through many kilometers through ground to come back. It just doesn't make sense to me.
Thanks for your help,
Adam






RE: SWER (Single-Wire Earth Return)
RE: SWER (Single-Wire Earth Return)
I look after around 20 SWER sites and aside from a couple of intermittent issues, my experience is that the system works as well as can be expected.
RE: SWER (Single-Wire Earth Return)
I remember seeing one of these in the backblocks of New Zealand where it might have been 10 miles between customers. Can you give us a loss comparison between earth return and conventional 2 wire system in your experience.
What proportion of the voltage drop is in the wire, compared to earth return? How would you allow for voltage sag with load to give the customer a steady supply voltage?
Thanks
Roy
RE: SWER (Single-Wire Earth Return)
The limitation with regards to current is more to do with concerns over safety and electromagnetic interference when running current through earth than volt-drop or efficiency. NZ's HVDC link will run up to 2000A via earth return when in monopole operation.
h
RE: SWER (Single-Wire Earth Return)
2000 A on a single return would be interesting - these must be the SWER isolation poles I see with the fencing around the base to stop animals (and people!) being exposed to a step potential problems at the base of the pole.
RE: SWER (Single-Wire Earth Return)
And welcome to Eng-Tips!
Keith Cress
kcress - http://www.flaminsystems.com
RE: SWER (Single-Wire Earth Return)
RE: SWER (Single-Wire Earth Return)
On HVDC, in some locations it is actually more efficient to use the ground as a return instead of a conductor. As David mentioned there is more than just efficency at stake though.
RE: SWER (Single-Wire Earth Return)