I think can't be 250 since that's not standardized in USA. Here you can see standardized EHV voltages in the states:
[Linked Image from 3.bp.blogspot.com]

Hard to tell just by the insulators (changes form location to location). Difference between 230 and 345 isn't so big

Last edited by Vlado; 09/20/16 09:11 AM.