2 phases 480V between phases 250V to Earth - Split phase ??

[m4tty]

Whats it all about ??

cheers

 

[Lee321]

more info needed

at a service head?

 

[Andy™]

most likely split phase - each phase is 180

 

[Riggy]

My understanding, and I may be wrong, is that it's fed from a centre tapped transformer (240-0-240) giving the readings you state.

As Andy says, used a lot in rural areas, 2 wire overhead supply (11kV) to a transformer, split phase out, keeps cable & transformer sizes down.