Model Railway Forum

Hi everyone,
This question is for Brian.
I have an accessory BUS split into 2x 16 ft lengths, on each of these I have 15/16 Dcc Concepts Colbalt IP Motors, recently replaced 6 motors that would not decenter, now some of the motors will suddenly switch direction all by themselves. I have checked all wiring for shorts etc and all seems well.
Do I need to put some gizmo between the ends of the BUS or just tape up?
John Gillott

I would suggest contact DCCconcepts direct sales@dccconcepts.com or via https://www.dccconcepts.com/contact-us/

They will be fast on the reply .

Firstly, what DCC system is powering everything?

You can fit filters to both rail and accessory bus pairs, as any noise generated in one is likely to appear in the other as usually the two bus pairs are connected together at some place unless you have a totally separate DCC system for each bus? No harm would be done by fitting them
On a bus pair of wire runs of 16ft in length I would ensure the two bus pairs are twisted together in their pairs (keeping each pair separated too), twisting around 10 times per Mtr.

Thanks Brian, where will I find the filters or can I make them myself?

Hi
DCC Concepts sell them ready made (quite expensive for what the are) or make your own as per my web sites details... Link to filters

Thanks Brian, that’s a great help, will update when fitted.

I would also recommend talking to DCC Concepts about the problem. This issue has been reported elsewhere with these motors and they may well have a solution for it. Generally speaking, bus terminators (or snubbers) should only really be needed with longer bus lengths, typically more than 30ft in length, and yours is only 16ft.

Additionally Bus Filters also help with any spikes appearing on the bus pair. Fitting them will never hurt.

Try this worked with my Cobalts...

https://www.dccconcepts.com/manual/coba ... nd-diodes/

The Diodes are only used in the wires that provide optional push button or switch operation.
They are not used in the DCC feed pair of wires.
There has been no mention of manual override switching where the diodes would possibly be used, but if the Cobalt's are additionally switched by manual means then do fit them PDQ.