Derailing shorts with Lionel engines

[Anonymous]

All of my recent Lionel Diesel acquisitions
within the past three years severely short
when they derail resulting in a complete
meltdown of all the internal wiring even before
my ZW circuit breaker opens. I'm relatively new to the hobby (3+ years), is there something
I'm missing or am I going to have to just keep
mailing my engines back to Lionel? Help!

[Algonquin]

Hi Gene,

My layout is powered by postwar ZWs. I run TMCC engines with a Command Base tied into the ground circuit of my power supplies. I have had many spectacular derailments and so far have not damaged any of the circuit boards.

However, I was concerned with issues of overcurrent and voltage spikes based on discussions with other operators so I contacted Lionel. During discussions I had with a Lionel technician a couple months ago, the technician indicated that with my current set-up, my TMCC locomotive circuit boards would be more susceptible to overcurrent events. He indicated that the circuit breakers in the postwar ZWs are not fast enough to always protect the boards from overcurrent events. The technician indicated that newer power supplies have much faster circuit breakers and suggested that I either upgrade to newer power supplies or install newer breakers. The technician indicated that Lionel does not currently offer overcurrent circuit breakers to install downstream of my transformers.

Older transformers, like the ZW, have thermal circuit breakers. These require time to heat up due to high amperage before they open. These circuit breakers may not open for several seconds and therefore, provide only limited protection from overcurrent events. Newer electronic circuit breakers (in most new transformers) open much faster and provide much better overcurrent protection.

I have since reduced the power supply setting of my ZWs to about 16 volts (instead of the 18-24 volts a ZW can provide at full open) when running in command mode. The engines still run fine but there is less voltage potential to the track reducing the severity of derailment overcurrents.

It sounds like you have had a lot of problems with fried boards. There may be something else going on. If you can provide more specific details like how the power is set up to your layout and the specific engine models that fried and how it happened, I may be able to provide some additional insite.

Tim P.