This is the difference between
2x120 = 240 volt “split phase”
and
2 x 120 = 208 bolt “split phase”
In your setup you only have 2 out 3 phases connected to your premises.
Let’s say you have L1 & L2, and your neighbor has L2 & L3 and your next neighbor has L3 & L1
The transformer needs to balance that.
Btw: in my street we have 18 kV at the overhead lines, not 11kV 
As a squirrel found out trying to hide some acorns in an automated switch device. Didn’t survive that and took the grid down when it arced and the lightning arrestors went up in smoke.
That was an expensive squirrel.