@Arnold D. Cribari posted:So, does it follow that I won't have this problem as long as I do not connect the ground accessory wires to the common bus wire for the main lines and sidings?
What problem do we speak of? Connecting or not connecting the grounds of phased transformers does not pose a problem either way. Generally speaking, most Lionel documentation recommendations are around one single common ground circuit. Connecting the common ground terminals on all transformers (in phase) would be the direction I would recommend and have personally taken on my layouts. It is more adventitious in my opinion do things in this single common ground manner to avoid more complex situations with track activated accessories such as crossing gates, non-derailing switches (O22s), connecting signals, operating cars and so on.
What is said above about additive current and whatnot is true, but generally this is addressed naturally because one can have multiple taps from the common ground to spread the load out and not need to run chunky wire everywhere.
