Jump to content

Wiring my DCC layout


AndyHead78

Recommended Posts

Hello again,

When it comes to wiring my layout, I'm not entirely sure what wiring I will need for my power bus and for the drop-down wires from my accessories (mainly point motors). Is there any particular type and size of wire I should use, and can you recommend where to get it from?

Any advice would be greatly appreciated.

Link to comment
Share on other sites

Hi

Here is my take for ensuring trouble free DCC operation..

Bus Wire... 32/0.2mm Equipment wire.

Droppers Bus to rail/accessory decoder....  16/0.2mm or 7/0.2mm equipment wire.  Use 7/0.2mm where every section of track has a pair of droppers or if you're relying on rail joiners (Fishplates) to pass power and data rail to rail then use 16/0.2mm equipment wire on every second or third section of track and fro accessory decoder feeds.

Solenoid Point Motor feed and return... 16/0.2mm equipment wire.  This applies whether via  DCC accessory decoder or conventional analogue wired.

 

Suppliers of wire range in the UK from ebay, Brimal,  CPC Farnell and Rapid etc and there are many other suppliers too. Some only sell 100Mtr reels while others sell smaller cut lengths of 10Mtr or less etc

What ever insulation colours you opt for for the bus pair, then obtain the same two insulation colours for the droppers. Then far less chance of accidentally getting them swapped around and causing a short circuit

Link to comment
Share on other sites

Just to add to FB's reply.

.

The xx/yy mm code means the number of strands [xx] and the thickness of each individual strand [yy] in mm.

.

The cheapest per metre way to buy wire, is to buy it on 100 metre drums from the online component suppliers that FB mentions i.e Rapidonline, CPC, Farnell. Fine if you want large quantities. For shorter lengths, then the cost per metre can go up significantly [even if the final price you pay is lower]. To get an idea of the typical short length costs search ebay using the 24/0.2mm or 16/0.2mm or 7/0.2mm terms as appropriate.

.

The most expensive way of buying this type of wire is, in my opinion, to buy it from a 'Model Railway Shop' whether in person over the counter or online.

.

This following statement usually opens up a range of opinions, but if 'best engineering practices' for DCC wiring is employed then there is benefit in making the main DCC track BUS from a 'twisted pair'. Some specialist 'Model Railway' suppliers sell DCC BUS wires that are already twisted, but it is easy enough to twist normal wires yourself as you install the cabling. It only requires about 5 or 6 twists per metre which isn't too onerous.

Link to comment
Share on other sites

Do not underestimate the overall length of dropper wires you will need, especially if buying shorter lengths. You will likely have wished you had gone for the longer reels as you run out time and agin. Main  bus wire length is easier to estimate.

 

For main bus wire I use stripped out household ring main cable, for dropper wires I buy 50m rolls of twin core flex mains cable and strip that out of the sheath. I strip the wires from the sheath so there is no confusion that it may be mains cable that could be inadvertantly connected to the house mains supply. Screw-fix or tool-station are a good cheap source of mains cable.

Link to comment
Share on other sites

Brilliant. Thank you.

Next newbie question...

I'm going to go with red and black wires for my main power bus for my positive and negative polarities. What will I need for the point motors? Is it just a case of needing two wires to connect the point motors to the decoder, then to the bus wire (one each for positive and negative again), or do I need more than that?

Link to comment
Share on other sites

Accessory decoders can connect to your track bus but they hive off some of the available power and they can become problematic if a loco derails and shorts the track bus.

 

It is better to run them from their own bus, again two wires from the controller feed the accessory decoder but for solenoid point motors you need three wires - a common wire and one for each way. Unfortunately although the colours black, red and green are generally used Peco and Hornby use them in a different order. Ditto signal lamps. You of course can use any three colours you like, just keep the code constant across your layout.

Link to comment
Share on other sites

Thanks RAF96.

So I should have one bus wire to power the track, and a separate one for the accessories (mainly point motors) to connect to running alongside it?

Does the power bus have two wires and the accessory bus have three wires?

Are there any easy to follow diagrams that show how to connect the decoders? 

Apologies for all the questions, but I really don't want to mess this up and buy bits I don't need!

Link to comment
Share on other sites

Just to eliminate any doubt whatsoever.

.

The wiring that you connect to your point motors, MUST NOT under any circumstance come into direct contact with the wires that connect to your track. The point motor wiring goes to the 'Ports' side of your DCC Accessory Decoder. It is the 'Track' side of the Accessory Decoder that connects to your DCC controller 'Track' output terminals.

.

What will I need for the point motors? Is it just a case of needing two wires to connect the point motors....

.

Solenoid based point motors need 3 wires not 2. Each port on the Accessory Decoder has three terminals [the R8247 Hornby one mark these three terminals + C - ]

.

The + and - DO NOT indicate positive and negative polarity. The Hornby convention is that the + equates to taking the left route through a point and the - equates to taking the right route through a point. The C equates to the 'Common' return [which is the centre tap of a twin coil Solenoid point motor].

Link to comment
Share on other sites

Excellent. I know what I'm doing with that now.

I do have another query regarding the power bus, but it would be easier to explain and get an answer if I could upload my layout diagram from SCARM. Once I've figured out how to do that I'll ask the next bit...

Link to comment
Share on other sites

Read the thread in the "Forum & Website feedback" section [located at the very bottom of the forum index page] titled "403 Forbidden error message".

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
×
  • Create New...