Adrian, on my last layout I ran MU's of 5 to 6 engines pulling up to 70 coal hoppers at times with all smoke units on. I needed two Z1000's in parallel on all 4 TIU channels (4 blocks @ 28 feet each), for 200 watts per channel. One brick per channel couldn't handle a train that size. The breakers would kick for no reason other then over current draw. When I started paralleling bricks together, it was easy to find if one brick was out of phase with the other, it simply pops one of the breaker's when you tie them together and power up. I also found that when two bricks are in parallel, both breakers would never kick together, when there was a derailment. Instead, the fuse in the TIU would blow. So I installed automotive (14 gauge) inline blade fuse holders on the TIU's input side. They come with a red LED that lights up when the fuse is blown which is a great feature. I started with 10 amp fuses but they couldn't handle a train that size. So I had to move up to 15 amp. I also had TVS's mounted on each MTH lock-on which would get very hot (but that may be normal for them). I have PSX breakers but never hooked them up. If I remember correctly it was because they could only handle 10 amps. I'm not sure on that though. That set up of 200 watts per channel was plenty and worked great until I dismantled the layout to move. Two 180's may be over kill. Wouldn't that give you 360 watts per channel? I would think 180 watts should handle the job. One thing I would like to do when I build my next layout would be to add an electric eye to each of the blade fuse holders, that would see the LED light up then throw a switch that would kill power to all the bricks. It sucks when one block dies and all the others stay alive when your running MU's and a long train.
