Ok, I just also blew a fuse and here are the circumstances:
I had the DCS connected to two separate loops. Both running P3 engines pulling passenger cars. The Explorer was powered by a z1000. One track had a passenger car derail. Poof.
Both engines are fine. But I'm really surprised neither the Explorer breaker nor the z1000 tripped, and a fuse blew instead. I will head to auto store in the morning and buy a new fuse. I hope the Explorer is not toasted.