Why would Lionel Fast track power track smoke and melt some plastic under the roadbed?

You had a bad connection with the power wires under the track.

Thanks. I tried rapping the wires underneath the track in electric tape. Track still smokes and gets hot. Is there a fix or do I need to purchase a new power track? Thoughts on the cause of this?

I think that switching to a heavier gauge wire might be the answer.  At least 18 gauge wire would bea good start.

Stuart

At the very least, the wire probably needs to be replaced. Depending how bad the melting of the plastic under the track is, maybe the whole thing.

Once there was a high current condition that started the original heating/smoking, it probably damaged the wire and/or it's connection to the terminals that are clipped on to the "tabs" under the track.  covering the possibly compromised wires with tape won't "heal" them, it just means you will have smoke/burning under the tape.

Even if the cause may have been a loose connection at the track the first time, at this point the wire is quite likely damaged as well.  So even if you correct the connection to be better, you now may have a new problem with the wire, damaged by the first event.

If it's hot enough to burn/smoke, it very well may have also compromised the connection of the wire to the terminal on the end of the wire.

Stuart's suggestion of using heavier wire is a good one, but it means you need to have the little push on connectors as a part and be able to crimp or solder a heavier wire to make a better connection than the small wire that comes with the Terminal Track as purchased.

-Dave

Thanks for responses. You've given me some ideas that may be worth a try.

Best solution I found for this type of problem on my layout was to get rid of the connectors and solder the wire to the terminals instead.  I still run my postwar F3 diesels with 2500 series passenger cars and can see currents upwards of 4.5 amps.  In general, most fastrack sections have terminals and I would opt for using a different section to make connection.  Likewise, the original wire may have become annealed due to the heat and would be a big risk if it were re-used.  I use 16 gauge stranded wire for all feeds.  

Regards,  Phranzdan

I have extra connectors that fit the track. I would be glad to send you some, if you want to go that route.

yep, like they said, too much current for the wire being used. I would guess that you bought a 10" terminal track and used the wire that was included.

The subway set with lights may draw about 3-3.5 amps, the Z-1000 is good for 5.5 amps. The breaker would kick if you had a short. Therefore, Watson, it's the wire gauge.

I, too, have quick disconnect crimp connectors if you want some. email me. they are .110 quick disconnect female crimp or solder connector. I also use 16 gauge stranded for track feeders.

Problem solved: I used 16 gauge wire that I soldered to the track. Been running the trains for the past three days and all is well. Thanks all for your ideas.

Good to hear- thanks for posting the solution - it will help others

I agree Carl, it is nice when the solution is found and posted on the forum.

Ray