Steam engine

Are you sure it's the loco?  Do you have another loco, or lighted car you can try to make sure that your short isn't in the layout or wiring?

Check the tetherless drawbar. It may have come slightly loose when the engine derailed. Unplug it and plug it back in securely. They are a bit finicky at times...

Also try to run it conventional mode with out the DCS if you have a transformer control arrangement...

Tom

I agree try powering up the layout with no trains on the track if it trips  the tiu might have  shorted tvs diodes, other wise try a different engine as the other person had said. ps3 engines are easily damaged with track shorts so are ps 2 also, you never want shorts if you can avoid them!! 

He has DCS Remote commander not TIU.   True to test track with nothing installed.  If that does not short, you can retry engine, but yes it is possible you shorted the board and it is overloading the Remote commander transformer.  G

Thanks guys for all your suggestions. I have tried them all. My passenger cars are all alight. My other engine runs very well still. The only time it shorts out the power pack is when I place the engine on the track. All other aspects of the track layout work. Onlt when the engine is put on the tracks does it trip the fuse. Sounds like the engine wasn't  working properly when I bought it. Needs a  REPAIR>

Did you check for any loose wires? I had a new out of the box engine that tripped the breaker everytime I put the power on. I took it back to my dealer. He opened it up and I had a wire that was loose. On one of my conventional trains it all a sudden stopped and then kept tripping the breaker. I had a wire that had a bare spot thus shorting and tripping the breaker.