We are currently working with an Engineering firm that is designing power distribution in a control room. The specification is to bring 4, No. 6 conductors into a distribution box and which will connect the 6509 using an L6-30, two 220V conductors and an isolated ground. The fourth conductor is safety ground which is tied to the rack in the junction box. The question is this; is the ground in the 6509 isolated from the chassis or is it connected. If its connected, we loose our isolated ground.Any help would be appreciated.