Thanks for the resonse.
I suggest that others will have a better understanding of this topic. I am doing an American layout so most of what I read is based on their practices which are often NCE and Digitrax. However here are a few points:
1. A circuit breaker will isolate a smaller section of track. Several circuit breakers can be combined into one booster power district. This allows a short circuit to effect a smaller part of the layout than a booster.
2. LIke a booster it will protect against excess current but the PSXX can actually limit a configurable maximum current over time. They argue that it protects the booster because that current can be below the booster trip value. This is supposed to help with 'keep-alives' charging up (eg the ESU PowerPack). Tony's Train Exchange explains this:?
https://tonystrains.com/news/new-psxx-current-limit-performance.
3. I think that some also protect against voltage spikes and act as a transient peak limiter. I have no reference to quote for this. I saw it on YouTube on a DCC Guy (Model Railroading) channel.
However, since I am now getting into Railcom, its protocol apparently is not compatible with the PSXX. The PSXX sees Railcom switching off the track power rapidly and doesn't like it. But NCE EB-1 is not so effected. I have no idea if it's a better circuit breaker overall however.
My counter counter question is: since your boosters are 'only' 3 amps as opposed to the 5 or 8 amps of something like Digitrax, perhaps this isn't as important any more since we would need twice as many of your boosters. My design scribbles show me actually using as many of your boosters as I currently have in PSXXs.
Oldngrey