Wire gauges

[Potrail2378]

Hi, although I have converted many (30+) loco's from DC to DCC, I still don't know what size/gauge of wire I am using! Sounds strange, but it's true. I usually just get an old scart lead, cut the ends off, and salvage the wires inside.

But what actual gauge should I be asking for if I were to buy decoder wire?

Thanks in advance.

[Brew Man]

CM3 Models have it here Decoder Wire

[Chrissaf]

The wire used on the actual decoder tend to be thinner than the wires used for wiring a socket within a loco.

In my opinion the most commonly available thin wire that is available in all the standard decoder colours is termed "Equipment Wire" and is defined as the number of strands of wire mm diameter. For example 7/0.2mm. This wire [7/0.2mm] is thicker and stiffer than that that is ideal, and definitely too thick for decoders themselves. It is OK for fixed wiring within a loco, but too stiff to provide flexible links between pieces of rolling stock or movable parts within locos [rotating bogie wheel pickups for example].

Another type of wire is termed "Strapping Wire", this wire can have more readily available thinner options, but tends to be solid conductor rather than stranded, so not really suitable in my opinion.

Stranded wire that is thinner than 7/0.2mm is available but much harder to find. Ebay sellers tend to focus on Number of strands/0.2mm wire versions.

The wire used on decoders by the manufacturers is typically 7/0.079mm which has an overall outer diameter of 0.5mm and is rated at 1.2 amps. This in my view is worth the extra expense of tracking down a supplier. In the UK, the Wickness Model Shop sells this wire specification in all the decoder colours, but at an inflated price. The next nearest equivalent to look for is 7/0.1mm wire and would be ideal for internal loco wiring and socket installations.

Try and avoid searching for wire using AWG type specifications, the AWG wire specification variations are not as straight forward and clear cut as the X/Ymm wire definitions.

[Brew Man]

The wire I pointed to above is 7/0.1, so a reasonable substitute.

[ColinB]

The issue I have had is a lot of people that advertise DCC wire, sell the PTFE coated wire. Although it is quite thin, it is difficult to strip even though I know how to and is not very flexible, mostly all of the wire advertised is this. Then other people sell "wire wrapping" wire ever so thin with a single core as Chrissaf says not a good idea. YouChoos do quite good wire the only issue is it is a bit too thin, but it is multistrand. I have been using the wire that comes with some Hornby DCC sockets if they are wired. I did raise a topic about it ages ago where Chrissaf kindly told me the right size. Trying to search for it on the RS or Farnell websites is a nightmare, their search engines don't work that well. I will do a search on Wickness Model Shop to see if theirs is any better, I don't use a lot so cost is not so much of an issue if it is the right stuff.

[Chrissaf]

Wickness Models direct link.

https://wicknessmodels.co.uk/product/fine-decoder-wire-choose-colour-quantity-copy/

[ColinB]

Thanks Chrissaf. I did find it eventually by searching their site.

[96RAF]

Roads & Rails sells what he describes as decoder wire in a big spool of 8 different colours and as a shorter length of 10 colour ribbon cable. Reasonable prices too.

https://www.roads-and-rails.co.uk/collections/accessories/products/40m-of-dcc-decoder-wire-in-10-colours

Unfortunately this one is sold out for now...

https://www.roads-and-rails.co.uk/collections/accessories/products/approx-250m-of-dcc-decoder-wire-in-8-colours

[ColinB]

Yes 96RAF unless he has changed he sells the single core wire wrapping type, I emailed when I first saw it. He might have changed though it was a while ago.

[Potrail2378]

Thanks for the info, gentlemen.

[The son of Triangman]

Another thing to consider, is the current you need to pass through the wire. 7/0.2 for instance is a theoretical 1.4 Amp max, but is normally rated at 1Amp. 7/0.1 theoretically is 700ma, but is usually rated at 500 Milliamps.