Protection from old ZW and Kw transformer spiking with new Lionel/MTh equipment

Your transformers  and railpower wire runs are protected by either fast blow fuses or breakers that trip with in a few seconds (hopefully not slow as 9 or 10) from overcurrent surges. Your modern electronic Locomotives/Tender boards and their fragile wires are protected from voltage spikes (which do not trip breakers or blow fuses() by installation of  Transient Voltage Suppressors (TVS). You can install the TVS across the pw transformers "A "(B,C,D) and "U" terminals. Closer to the track railpower  connections from the transformer is better but not essential. Remember: Circuit Breakers or Fuses for Transformers-----TVS for Modern Locomotives

Fuzzy photo just below:

Cartridge fast blow fuse block on 1992 operation with 5 power districts powered by 3 pw ZWs , later by 180 PoHos.(dismantled '08). Fuses are installed inline on the Hot conductors, the  colored wires + black are Hot , the white wire is Common. You can buy inline fuse holders fairly cheap...don't need a block as shown:

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 Fuzzy photos of TVS below:

I see issues many times where the old ZW does not trip fast enough.  Good post.

Westy,

   Remember also if you are running DCS, the TVS is built right into the TIU, however you still need to put Resettable 7 - 10 Amp Breakers on every red line between the old ZW and your TIU.  

Have fun building your layout!

PCRR/Dave

My gut feeling is that if you really want spike protection, put a TVS in the loco.

Good job Dewey.

I just had one of my fast-acting 10-amp fuses blow the other day while running my MTH Dreyfuss Hudson. While rolling along at slow speed, the screw that holds the pilot truck on just barely grazed the center rail, and in a split second, power was cut off and no damage was done. Whether or not my ZW's breaker would've tripped in time, I don't want to find out the hard way. A new fuse, and a small piece of electrical tape on the bottom of the Hudson's pilot truck, and the train was rolling again. 

John