Dave Zucal posted:I personally don't think it's big over kill at all. Unlike a fuse, we have no way of knowing the TVS's in our TIUs are still handling all the spikes they've been getting exposed to? Also, how well do they work in the TIU if the layout is powered in passive mode? Distance applies too. For instance, if the front truck jumps the rail on a steamer, the sparks are much closer to a TVS installed in the engine, then the ones installed in the TIU. On some big layouts the TIU could be over 50' away. Then you have the guy who's pulling 50 cars with 6 engines who's drawing high amps through a channel that could have a bad TVS. Could you imagine all 6 of those engines getting fried at once from a spike that failed to get grounded because the TVS was bad and the breaker on the brick was too slow to open. Heck, for how cheap these components are, it wouldn't hurt to put two in an engine and maybe even a re-settable fuse.
Thsnks for that explanation. Very good case you make.
