Re: Non-terminal snubbers

Jim Zarnick

Congrats Allan!  I subscribe to several HO Facebook groups and when people start asking DCC type wiring question I habitually reference J Looking forward to reading you in MR.


I’ve been paying close attention to this dialog as I wonder if my own snubbers are in the right place.  So I’ll ask.


I have NCE DCC hardware on the track circuits. (I used to live 2 miles from their shop so I’m loyal, J


Layout is multi deck  around the walls with a helix connecting one end of the wall based decks and a platform in the center of the room that connects the 2 decks, allowing continuous running.  Mainline is double and 267 feet long.


2 NCE Boosters

12 gauge stranded buses from Boosters. Boosters are wired together for common ground.

5 locations exist around the layout connecting  the buses to 6 NCE Circuit Breakers.

Each circuit breaker is connected to a multi terminal distribution panel like the Micro Structure product.  2 sides 10-12 terminals each side.

My snubbers sit on the bottom of these panels, so 1 snubber per circuit breaker protected district.

From the distro panels after the circuit breaker each block, which have insulation joiners on both rails, have a twisted pair of 18 gauge wire running to them.

One of the block wires runs through an NCE block detector.

Each piece of track has 22 gauge feeders connected the 18 gauge block wires (IDCs everywhere!).


So my snubbers are not at the end of runs, as technically the end of my runs are at the end of each block. But my snubbers are before the block detectors.


In general I have very few electrical issues but:

1)      I do have the occasional runaway, 

2)      I do have the occasional locomotive that stops and restarts while the other loco in the consist does not, and

3)      I do have an occasional issue with the block detectors not picking up the resistor wheelsets, which is annoying to the signal system and crossing gates.


Lots of info here, but welcome knowing if I have my snubbers in the best place?


Thanks for the great dialogs in this group!




Jim Zarnick



From: [] On Behalf Of wirefordcc
Sent: Saturday, March 14, 2020 10:18 AM
Subject: Re: [w4dccqa] Non-terminal snubbers


Hi Dan,


One common snubber at the end of the district that ties all the lines to it should work.  Do not put them after the block detector CT (current transformer) coil as you might get a false occupied block.


Starting in January, I will be writing the DCC Corner column for Model Railroader.  Can I use your question?  If so, please provide me with your city and state.


Thank you



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