[DJ88]

Steve,

Just thought of a great way to describe it interms of the ship.

Ok. we are in te MCR and the ET of the watch calls and says he is flashing up a chiller and needs anothe DG broght online. Yo bring it up no problem but when you go to bring it on the bus you forget to Sync it with the other DG. What happens next? Ship goes black, ET gets ****ed and EO, CERA and everyone else gets really pi$$ed.

The yellow leads aren't ground as you are thinking. They are a return lead for an AC circuit. You have just hooked to DG's together and flipped the switch on both at the same time. On ship the board trips and the ship goes dark. At home if you don't have GFCI's you get smoke.