With my new train room it's all new 20 amp breakers. I have a ZW-275 which I like better each time I use it. To keep from melting things I bought Lionel #91 breakers from "back in the day" that I think were made for it. I found 5 of them. I also have a 1033 that I do not use to much yet. The breakers are adjustable. I just crank them up and then run a train and then crank it down until it trips then back it off 1/4 to 1/2 turn until it runs. Derailments pop them immediately and I am far more confident than I was before. I had melted wire twice before this. And fried a loco that I have a new board for. It's good as it lets me vary the cutoff amps since the trains vary in what they draw depending on the engine and what the other cars pull.
Frank
