I have an exceptionally large layout. It is powered by a Z4000, a ZW, 2 Z transformers and 2 R transformers. I use a common ground for all track, accessories and turnouts. There are 2 main lines each powered by one of the Z4000 throttles. I am replacing the Z4000 with a Lionel ZW L transformer. I assume the ZW L has to be phased like other transformers. If so, is there a recommended technique?