I remember when in Southern California, (SCE territory) seeing most polemount distribution transformers hooked between two phases rather than in wye (one phase to ground/neutral) on the HV side... can anyone tell me why this is? Is it just a preferred method, or is it to do with ground fault detection being possible on such a network, to detect downed lines during a 'quake maybe?

This has been bugging me for some time so I thought I'd ask the experts. Also, does anyone know of any sites with details on the internal construction of polemount transformers as used in North America? Originally being from the UK, the round style is still somewhat unusual to me, and I was wondering what type of core etc these things use [Linked Image]