I am almost embarrased to ask but does anyone know the reason behind them ? I am 13 years into this and the many systems that i have worked on there truely is no consistancy to where they are put! The many people that i have asked, have not really cleared up the reason. Maybe i am looking for the engineering reason, or maybe the technical reasoning behind it ! Maybe the power company is doing something that I am not paying attention to. Anyway if anyone has any input as to why they are or what there purpose is please help! no smart asses please ! Thank you in advance, and be safe!!! TO ALL HAVE A SAFE AND HAPPY 4 TH ! GOD BLESS THE USA!