Model Railway Forum

Hi All,

Just have a few questions about the wiring and electrical's side of model railway layouts. This is my first layout and my biggest worry is the wiring side of it as i've had no electrical side in the past with anything.

I understand the concept as such with bus wires and dropper wires which are soldered to the track however, i'm unsure what type of wire, how often dropper wires should be placed along the track, how it all fixes together (Dropper wire to bus wire) etc.

Does anybody know of any guides or videos which shows all of this or is there an easier solution ideally without having to solder to be able to connect track to the controller?

Any help is appreciated.

One of many web sites

https://brian-lambert.co.uk/Electrical_Page_1.html

or books like this
https://www.amazon.co.uk/gp/product/071 ... bl_vppi_i2

ConnorL wrote: ↑Thu May 23, 2019 9:56 pm

I understand the concept as such with bus wires and dropper wires which are soldered to the track however, i'm unsure what type of wire, how often dropper wires should be placed along the track, how it all fixes together (Dropper wire to bus wire) etc.

Does anybody know of any guides or videos which shows all of this or is there an easier solution ideally without having to solder to be able to connect track to the controller.

Personally I connect droppers to each section of track so there is no reliance on the fishplates, I know of one modeller who would even put droppers on a 2" section so how far you go is up to you.

As for type of wire, droppers can be quite thin as there is a limit to how many current drawing devices (locos) you can have in each section of track thus the current carrying capacity of each dropper can be quite low. So if droppers are quite short than 7/0.2 wire is adequate 16/0.2 is definetly OK. Stranded or solid? I prefer stranded, thin solid wires snap easily if subjected to any movement. Some people use old domestic cable for the bus typically 1.5mm2 to 2.5mm2 this is usually a solid single core, myself I find stranded cable typically 50/0.2 more convenient to work with. Bus wires need to be quite substantial as they need to carry the total current being drawn by the layout and need to present as little resistance to the current to prevent voltage drops.

How to fix them together? This causes some heated debate, however, most would agree soldering is by far the best method. None soldering methods include terminal blocks, IDC connectors and spring loaded connectors.

Terminal blocks usually involve tightening a screw to secure a wire however if used in circumstances where vibration is an issue such as a portable layout then screws can come loose over time.

IDC (Insulation Displacment Connectors) eg. Scotch Lok use a slotted blade within the the connector to connect the wires. The blade cuts through the insulation making contact with the conductor inside the wires. These are colour coded to indicate which range of wires they are designed to connect generally they are similar in diameter. Problems occur when wires of very different diameters are used on a large connector the blade may not slice fully through the insulation on a thin wire whilst on a small connector on a thick wire the blade my actually slice through part of the conductor.

My own preference of non-soldered connectors are the spring loaded type eg. Wago connectors as these overcome both the issues mentioned above but at a price! Wagos will grip wires down to 7/0.2 and up to 4mm2 more than enough for any layout wiring.

Richard

Thanks both for your help, really useful information.