one of our projects has the Electrical for AC units on roof. There is 400 HA panel XFMR and LV panel located on roof and near center of roodThere is no detail showing how the equipment on roof will sit and or how the 400a panel will be mounted. The roof is made of steel trusses with tin/corrugated roof deck with that white membrane best I can describe. If its up to me I am considering an H frame or if I can mount on tilt wall Parapet wall, its about 5' and asking for a little help or should I consult the A&E for guidance in installation?