I was taught when my layout was in my childhood home, never leave with out unplugging the transformers. Now, I still follow that advice and unplug the transformers (ZW and LW) from the wall outlet when done. They plug into the ckt breaker strip first then the wall.
I had a similar problem with my ZW and had to make the repair to the bus bar. Running like it just came off the line. I only have one Lion Chief engine. All others are either Postwar or MPC era loco's.
Regards