In my area, it's all wye, and looks just like Greg's photo. MV on top, then the 3x 240V residential lines below (I forget which is the neutral out my way.) No protective grounded conductor on top, and plenty of blinking lights every time there's a lightning storm. This way, they only have to run one MV wire conductor out, and can share the grounded neutral for both the MV and LV lines.
They also seem to love to undersize them. Lessee... per NEC, my house requires a 200A service and is a dedicated fridge circuit from bumping up to a 400A service, and my two neighbors are similar... so of course the POCO puts a 25kVA pole pig up that's only rated for 104A to feed us all.
5 new houses just down the street, each with electric heat and requiring 200A service? CW (and NEC) says 240kVA. POCO puts a 50kVA on the pole. And we wonder why the power fails so much on really hot or really cold days...
