Fastrack switches (or something?) shorting out layout

God knows it would only require a small glass to hold the sum total of my electrical knowledge but, have you made sure both transformers are in phase?

Curt

You are aware that a known problem wiith some fastrack swiches is that the terminals especially for aux power into the switch were ordered wrong compared to the labeling right? So the metal jumper installed they typically work and passed he factory test, but when you supply aux power to the switch, you wiire it to the track instead thus backfeeding the track power with aux power. Mostly affected the larger fastrack switches but it is a mistake that they could make wrong on any fastrack switch.

FWIW, a while back I got 13 each 072 fastrack switches, ALL 100% were internally miswired.

100% failure ratio- let that sink in from 3 different dealers. The supply chain is full of these.

Again, let me be clear, I'm saying you followed the labeling stamped in the bottom of the switch and manual, but there is a possible answer that internally when you connected aux power to the switch it's NOT wired to actual switch power logic, but instead either to track 3rd rail, or possibly ground making a short or at least backfeeding the rail.

Also, since you mentioned CW80, you are also aware early CW80 transformers may have the 2 red posts common and are problematic when using the accessory power in a situation like this? Again, with the transformer off, and not connected ohm out the red and black terminal posts of your CW80, if red are common- then that can be a major problem in his scenario of powering switches and track.

If the reds are common, you can wire the transformer backwards, wire red terminal post to outside rail, wire black terminal post to the 3rd rail, and the accessory black terminal post to aux switch power. This reverses the bell and whistle button functions, but would in theory correct the short- because of the backwards common between track and accessory power.

Again, most likely one of the 2 above scenarios- the switches internally miswired or the CW80 accessory power and incorrect "common".

https://ogrforum.ogaugerr.com/...fixed-voltage-option

https://ogrforum.ogaugerr.com/...9#152899748560979289

Thanks for all the replies.  I have ruled out the CW80 as the problem - I took it out of the system and put another older transformer in to take care of the track power, at least for now.  The problem remained, so I am pretty sure it must be one or more of the switches.

These switches were all purchased in 2015, except one which I bought just last month from Charles Ro.  The most recent one is a "command capable" switch, the others are not. 

This layout is a side project from my "regular" layout. We are setting this one up in our auto parts store as a temporary Christmas display.  We last used this bunch of Lionel switches in 2015 and I don't remember having this problem then, but I think the previous time we just used track power on them rather than wiring direct, so this issue didn't surface then.

I'll update again after I do some more investigating. Thanks all.

That when you see it, using track power with the jumper, they work.

Using aux power (AKA accessory power) is when the out of order internal screw terminal wire contacts compared to the stamped labels suddenly bites you.

And, using a different older transformer with less sensitive breakers can lead to burning up that internal switch wire.

Again, just a warning, the internal wiring is very small pvc insulated wire and when it burns up from a short from the mismatched labeling vs function, it can be ugly.

This isn't even the worst example, just the first I could find. In this case, they installed the jumper and wired track power and ground such that the switch was a dead short to track power. Yellow wire to outer rail bus connection. But one could easily have the same damage to the the red wire to center rail thinking it was aux in power.

We found two switches that were mis-wired. Fixed them up and all works well. Thanks again to all for the replies and links, this has been an education and now I am even more firmly in the "Ross Custom Switches" camp for my everyday train activity!