On my old layout without DCS, I had numerous PW transformers. I ran a hot bus wire for each and a shared common wire. All track and accessories connected to the same common bus wire. Phased the transformers and then daisy-chained the transformers' common terminals to each other. Understand all that. Easy peasy.
The new layout has DCS, so I used star/homerun wiring, and I read in the DCS Companion book that I should still connect all the common terminals of my transformers. No issue with my PW transformers this time either, until now.
I just bought two 180W Lionel Powerhouses to replace two of my lower output RW transformers, but the PH's don't have hot and common terminals like my PW transformers.
Can I daisy-chain their commons to the other transformers at the input terminals of the TIU? At the output terminals of the TIU? At the terminal blocks? Or, with 180W PH's, is connecting the common terminals unnecessary?