Breaker - TVS Box - Your Thoughts

I have TVS's at the power supply and at the track feeds... apparently, all for not.  The TVS's need to be inside locos' as close to the electronics as is humanly possible to arrest any voltage spikes... which hopefully, spares the electronics within.

A 10A breaker and a 2.3A wall wart.

That's not going to do a darn thing.

Lionchief power supplies detect short circuit current and have a decent internal shutdown system. This was done for safety reasons considering lionchief was aimed at children and track shorts might be likely.

Second- sorry you had a failure in the past and it was expensive, but the short you speak of likely was internal to the engine causing a short between DC output items and AC frame common. There is NO breaker on the planet that protects this type of fault.  Even if it was a different short- a 10A breaker and anything Lionchief or Lionchief Plus is pretty insane overkill, and knowing the wiring of those engines and components being well under 10A and nowhere near that kind of power draw, that breaker will never trip and protect you train.

While TVS is good protection- however, running all modern low inductance Lionchief equipment, voltage spikes are not as prevalent as when running mixed postwar and modern electronics, so again I seriously doubt this saves the day or prevent anything given your chosen power source, a DC 2.3A rated switchmode power supply.

All I have to do is link this post about the burned up wiring and PCB in a modern typical Lionchief passenger car to really drive the point home about why a 10A breaker is a bad idea with the hardware you are trying to run.

https://ogrforum.com/topic/158674373723181699

Verron

Any suggestions on changes?    Even if it's "I'm wasting my time" which is what I believe you are trying to tell me.  Different AIRPAX ? 2.0A or 2.5A?

Given you are already running an insanely low 2.3A power supply, putting an airpax breaker- even one rated at say 2A doesn't make a whole lot of sense. It's one thing if you were running larger power supplies (transformers) like an older ZW or something like a Z4000 capable of 10A, but also trains that actually need that much power.

Lionel matched the power supply to the set in these lionchief sets. Again, you are not even running a high Wattage 54 Watt supply in some of the premium sets.

Look, sorry, I advocate for protection because I repair trains and I know what it costs and what protection works. But you also have to step back and look at the total picture. If I'm running an already protected DC wall wart supply, that is such low wattage in and of itself there are trains and loads it will not run- trying to "right size" even more specialized protection in the middle is just not a good return on investment.

To trip a breaker, you need more than the rated holding value. If your power source has a lower rating than the breaker, the breaker in theory can never trip. Granted, there is a capacitor on the output and for an instant a really dead short might trip say a 2.5A breaker, a slow partial short that is more realistic to a real life situation likely would never trip the airpax breaker before the power supply itself shut down. And going lower and finding a 2A breaker, well now that's less than the source, but we are slowly going near bare minimum power requirements for the train- especially with smoke units.

I want to stress- you bought some good components and they are valid in some situations for some folks layouts. But that's key- you have to look at the big picture, with data of all the components- the power sources (transformers), what they are capable of, what protections they have built in, what they lack in protection. Then you need some understanding of the trains and load that are expected- but even more so- understanding the limitations and gotchas of those trains (like Lionchief) where the wires and components have gotten so thin- they will not take a derailment short. What works on older heavier wiring and higher tiered trains and cars from the past, that both can take some current in a short and need some current to run- the breaker that works for them will cook a Lionchief and never trip. Conversely, a breaker that tries to protect a Lionchief engine is such a low rating- it might not be able to power Legacy and oldschool conventional trains due to their higher current ratings.

So yes, those boxes are good for future use but it's all about context.

Vernon,

Thank you for your feedback.  Very informative and lots of food for thought.

Zeke13

Your breaker box design looks very good and will find value if you use a power source capable of delivering more that 10 amps (Z4000, Z1000, ZW) as Vernon mentions. The use of the TVS in the box is fine as well--can't hurt. Although the TVS is more effective closest to the engine electronics, even MTH puts them in the TIU which may be some distance from the track power feed point.

In actual practice, the breaker most often will trip because of derailments.

Don't consider using an AIRPAX breaker below 7.5A because the lower amperage ones sometime buzz at the 18 VAC voltage.

Again, you did a great job but just need to change your power source.

Thanks to everyone for your feedback, very informative.  The "Fire in the Hole" post is an eye opener. 

I have long wanted to respond to the Forum’s electrical threads with “A Tale of Two Layouts” story.

Layout #1 is built on a solid tabletop made of six four foot joined squares of ¾ inch particle board, surfaced with brown indoor/outdoor “carpet.” All track was brand new K-Line Shadow-Rail/Super-Snap including eight K-Line 0-72 switches. All track sections were retrofitted with steel track pins where absent (except for insulators). This layout is almost as track quiet as a fine HO layout would be, and derailments happen only through failing to protect a stopped train by not throwing a switch behind it.

Layout #2 was built in a 20’ by 40’ back yard building constructed just for the owner’s double deck layout.  The two levels were independent. All track sections (tubular) were previously used, old and in poor to medium condition. All eleven 0-72 switches were late 1980’s Lionel. The owner loved big power so that he seemingly owned every Lionel Articulated Loco made since the Kughn era (about a dozen and all TMCC).  His favorite challenge was to operate four trains at a time, occasionally five.  The poor track work caused constant pilot and sometimes driver wheel derailments. It is surprising that the loco electronics for the most part survived the long shorts before his ancient ZW breakers would trip, if they'd trip at all. Immediate line power shutdown was not often quickly accessible.  Once the owner was encouraged to replace his ZW’s with 180 watt Lionel “Bricks,” protection levels were raised, although derailments continued.  This is written in the past tense as the owner has recently and sadly succumbed to elderly dementia, and is now living in a care facility. His layout’s future is not bright.

In conclusion, while electrical realities must be understood and properly applied, the mechanical aspects, like quality track work, are equally important.