Loco internal Wire Gauge - Track/Motor/Accessories

[curtis]

Forumers,

Apologies if this has been covered before but I couldn't find an answer on the forum. I wanted to check which wire gauges (AWG) you are using internally in your locos. I appreciate this is not

I've been using

• Track/Motor - 22 AWG
• Common (DEC+) - 22 AWG
• Light Accessories - 26 AWG
• 5v Smoke Stack - 22 AWG

For context, these are DCC locos - primarily LGB x1 and x2 motors and a single 1 PIKO x1 motor loco.

 

[Greg Elmassian]

22 too light for track and motor... at least 18. If you ran nothing but short trains with little LGB locos it might be ok.

Why use such light gauge wire?

Greg

 

[PhilP]

Most the OEM (read LGB) wiring in Europe, is what you would consider quite 'light'..

Most does not have a direct AWG equivalent. - Funnily enough, not being in America, we don't necessarily use 'AWG'.


You will find many 'large-scale' loco's in UK and Europe wired with '7/0.2' 'hook-up' wire.. This has a nominal rating of 1.4 Amps, but can do better, if you get the 'irradiated' jacket, as it does not melt so easily!

Of course, similar cross-section in a silicon insulated form, has a stoopid 7 Amp rating.. BUT that is at 140 Centigrade!!

 

[curtis]

Thanks, Greg. Andreas also suggested I increase the gauge of the wires.

The reason for the light wires is very much as PhilP said, it seemed to be the standard in the LGB locos I have. However, It occurred I was operating on assumed knowledge/practice so started looking into the topic. The after some reading and looking at gauge charts - it lead me to believe that was being too light as you said. However, was a little confused given I was using wires comparable to the manufacturer. Hence I decided just to ask this wise community.

Regarding the length of the trains - they're mostly pretty short. Max I usually run is x3 HSB passenger carriages at once and all my locos of continental narrow-gauge. My layouts are always temporary (being in an apartment and the balcony) which is limiting to any train length. As I work through digitising the fleet figured it was best to as the question early to address it early.

 

[Greg Elmassian]

Yes, and as I said in my post, if you use low current, single motors and short trains it's fine.

Remember that motors are very low resistance (impedance actually) so the wire itself can "consume" a fair amount of power under heavy loads. To me that is wasted energy, the heat produced is rarely an issue except when you have a short. The handling of over current is another discussion entirely.

So, for me, the larger gauge wire inside the loco for track and motor wiring (and in my case smoke units) makes more sense.

You can convert awg to metric easily, there are charts on the Internet.

Greg

 

[Paul M]

It's usually good practice to use the largest cable that is practical, physically and cost wise

 

[Greg Elmassian]

There is a bit of a caveat, make sure that you have overcurrent protection inside the loco, because a short circuit will melt the weakest link.

Here is a situation where the wire was plenty heavy, but no current limiting, and the circuit board traces went first during a short between the front and rear truck (very typical)

 

[Paul M]

There is a bit of a caveat, make sure that you have overcurrent protection inside the loco, because a short circuit will melt the weakest link.

Here is a situation where the wire was plenty heavy, but no current limiting, and the circuit board traces went first during a short between the front and rear truck (very typical)

You'll get banned from the Magic Circle Greg, you're not allowed to divulge the secrets of the Magic Smoke

 

[Greg Elmassian]

There's actually 2 traces there, and I burned up one with a derailment, fixed it, and then soon after burned up the other.

I now have PolySwitches to protect from this:

Basically one PolySwitch at EACH track pickup for EACH truck... works a treat as you say.

Greg