short circuit protection

Search the forum for TVS diode and circuit breaker.  Lots of threads about it.

The protective device should go between the transformer and the track.  I have a psx-1ac and it works great.  If you do a search on the ogr site you will find a lot of posts regarding this type of breaker.

Marty

^^ +1 on the PSX1-AC.

It’s saved me many times from shorts during the oh s*#t moments.

I use a Lionel postwar 91 circuit breaker and a TVS diode.  One of each for each throttle connected to the track. The circuit breaker should go into the wire between the A or D post on the ZW and the connection to the center rail. The TVS connects between the A and U wires where they connect to the track. It can go right on the lock on.

@David Johnston posted:

I use a Lionel postwar 91 circuit breaker and a TVS diode.  One of each for each throttle connected to the track. The circuit breaker should go into the wire between the A or D post on the ZW and the connection to the center rail. The TVS connects between the A and U wires where they connect to the track. It can go right on the lock on.

Be careful with postwar breakers - probably will not be fast enough for engines with modern electronics.

Here are recommendations for circuit breakers and transient voltage suppressors from gunrunnerjohn.  The circuit breaker goes in series with one of the wires from the transformer output to the track,  and the TVS across the two wires going from the transformer to the  track.  You don't need anything between the wall plug and the transformer.

"You can run your modern Lionel trains on post-war transformers. I'd make a couple of additions, one being a TVS protection diode, here's a good choice: 1500W 33.3V TVS at Digikey

Another addition is a modern circuit breaker or fuse. I personally prefer the Airpax Magnetic Circuit Breakers, or you can use 10A automotive fuses. I'm not really a fan of thermal circuit breakers, they're pretty slow to trip."

@360RPM posted:

I have finished wiring my 16 X 10 foot layout. I have a ZW and TW transformer. I want to add either a fuse or a circuit breaker to protect the modern locomotives I am running with the conventional post war locomotives.   Is a fuse OK or do I need a circuit breaker? Where do I insert the fuse? Between the hot on the ZW and the track?  Or between the plug and the input of the hot to the transformer?

Since you want to run Conventional Locomotives and Command, the PSX -AC series breakers will not work for Conventional operation because they won't pass low voltages.  See this topic for details: PSX1-AC.

When I researched this very question, I was looking for a better alternative to frequently having to replace Fast-Blow fuses on my layout.  Here's a link to that discussion thread which also includes links to where to buy them in different Amperages.

I now use Airpax Instant Breakers (one per ZW hot side output) and have been very happy with their performance.