# track power connector spacing



## mikey802it (Apr 26, 2020)

I am in the planning stages of rebuilding my outdoor garden layout. I haven't had trains outside for over 3 years now, since I HAD to finish deck first.

I am planning on a rectangular layout with 2 mainlines. the outer one being 10' diameter curves and the inside with 8' diameter curves. I do not anticipate running streamlined passenger cars, only coal trains and a small LGB passenger set.

How far apart should I place my track power connections? My backyard area is 40' x 20'. 

Any assistance would be greatly appreciated.

Thank you,

Mike McCaffery


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## krs (Feb 29, 2008)

Mike,


If you use good solid connections between the track elements, either soldering or rail clamps, you really only need a single power feed unless you want to set up different power sections to run multiple trains in analog.
The conductivity of code 332 brass track is much better than even 12 gauge copper wire.
The idea of multiple power feeds comes from the H0 modell crowd where that is needed for a larger layout; it is also a possible requirement if you use stainless steel code 332 track depending on the size of the layout.
But not necessary for code 332 brass or nickel-plated brass track.


PS: I used to have a nice bar chart to illustrate the conductivity of code 332 brass and the various AWG sizes of copper wire but can't lay my hand on it right now.


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## Treeman (Jan 6, 2008)

Krs is correct, brass is a very good conductor. The failure would be joints from rail to rail. I usally suggest running a feed to the far point of your layout. Low voltage landscape wire will do the job, #12 will reduce voltage drop.


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## KeithRB (Sep 25, 2015)

Will my brain says you are correct, the more conservative engineer in me says that 3-4 feeds is a good plan.


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## toddalin (Jan 4, 2008)

Treeman said:


> Krs is correct, brass is a very good conductor. The failure would be joints from rail to rail. I usally suggest running a feed to the far point of your layout. Low voltage landscape wire will do the job, #12 will reduce voltage drop.


If th track is a better conductor than the wire, doesn't it make more sense to run the feed wire to the nearest point and let the track carry the current to the farthest point?

If the current has to go though 250 feet of track, anyway, doesn't it make more sense to go through 250 feet of track and 20 feet of wire, rather than 250 feet of track and 50 feet of wire?

Also, the further you run the wire, aren't you more likely to accidently cut through it when gardening, or whatever?


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## Ironton (Jan 2, 2008)

I think the far point feed is a second feed. It is just in case there is a break in the continuity at a rail joint, the second feed would send power backwards through the section that would otherwise be cut off.


Also, when there are two breaks it will make it easier to locate them. Start an engine at each end and when it stops you know you have a bad connection at that area.


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## Naptowneng (Jun 14, 2010)

I have had good track power performance on my 180 ft of 332 brass track with one power tap and track clamps, either Aristo or Split Jaw. But I put in one more tap half way around, and it did not seem to make any difference. Keeping the tops of the track clean is more important in my experience. Pollen season does not help.....

Jerry


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## krs (Feb 29, 2008)

Bottom line is that the power feeds required in Large Scale depend on the particular layout configuration and what wishes to accomplish.


Reading Mike's original post, it sounded to me like he was thinking of the smaller scales like H0 and N where power feeds are required at regular intervals. That's because the cross-section of H0 and N scale rails is small and therefore conductivity is poor. That is not a problem in Large Scale at all - because of the large cross-section of code 332 rail, the conductivity of that track is better than what one would get with the heaviest copper wire people would use.
The only exception to that I can think of would be a very elongated dog-bone layout where a second feed to the return track at the centre would make some sense because the second power feed cable would be very short.


Running a second power feed cable to allow for power fed "backwards" in case there is one poor connection would only apply to a point-to-point layout - in a typical loop layout which Mike's seems to be, one poor connection wouldn't matter since power is fed automatically in both directions.


And I finally found the bar graph that shows the resistance of brass and stainless steel code 332 track compared to copper wire - it's attached.


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## Greg Elmassian (Jan 3, 2008)

Yes, first questions should have been:


what brand of track and metal
sectional or flex (number of joints)
clamps, stock joiners or bonded (soldered jumpers)


Then a good answer can be given. For the size you have, with clamps, or joiners in like new shape from LGB and grease in the joints, I'd put 2 feeds per loop.


The metal of the rails is irrelevant in most cases, it's the joints between sections.


Greg


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## Dan Pierce (Jan 2, 2008)

When I built my RR I did a figure 8. My power connection is to the 90 degree cross over on 2 of the 90 degree sides. I now feed both loops of the figure 8 from both sides of the 90 degree crossover thus eliminating the need for additional feeders. Note I only run approx. 50 feet for dogbone end to end with the crossover about midpoint, others have a much longer run and would need additional power connections. 15 years, no issues.


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## fyrekop (Sep 20, 2011)

I over-engineered my layout with power feeds about 30 feet apart in each of the 3 300+ foot loops. I used 10 gauge wire through conduit. Zero power issues as long as the track was clean. 
Track is a mix of Piko, LGB, and Aristo, some new - some used, with Snap Jaw joiners Only track issue is replacing tie strips due to high UV / heat in Az.


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## Treeman (Jan 6, 2008)

toddalin said:


> If th track is a better conductor than the wire, doesn't it make more sense to run the feed wire to the nearest point and let the track carry the current to the farthest point?
> 
> If the current has to go though 250 feet of track, anyway, doesn't it make more sense to go through 250 feet of track and 20 feet of wire, rather than 250 feet of track and 50 feet of wire?
> 
> Also, the further you run the wire, aren't you more likely to accidently cut through it when gardening, or whatever?


You are depending on the connection at every piece of rail. With a length of wire you have one connection.


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## krs (Feb 29, 2008)

Treeman said:


> You are depending on the connection at every piece of rail. With a length of wire you have one connection.



That is true, but in the end it doesn't matter unless you run a separate power feed to each individual section of track.


Take the example mentioned above:


> I over-engineered my layout with power feeds about 30 feet apart


Longest section of code 332 brass track is typically 4 feet.
One can buy longer rails but then shipping becomes an issue.
And I know many modellers use 12 and 24 inch sections.


But assuming 4 ft sections, then with a feed every 30 feet one still has 7 rail joints any one of which could interrupt the current flow and the extra power feed at the 30 foot point won't help.


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## Treeman (Jan 6, 2008)

krs said:


> Bottom line is that the power feeds required in Large Scale depend on the particular layout configuration and what wishes to accomplish.
> 
> 
> Reading Mike's original post, it sounded to me like he was thinking of the smaller scales like H0 and N where power feeds are required at regular intervals. That's because the cross-section of H0 and N scale rails is small and therefore conductivity is poor. That is not a problem in Large Scale at all - because of the large cross-section of code 332 rail, the conductivity of that track is better than what one would get with the heaviest copper wire people would use.
> ...


What about 2 bad rail joints?


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## krs (Feb 29, 2008)

Treeman said:


> What about 2 bad rail joints?



Are you referring to this:


> Running a second power feed cable to allow for power fed "backwards" in case there is one poor connection would only apply to a point-to-point layout - in a typical loop layout which Mike's seems to be, one poor connection wouldn't matter since power is fed automatically in both directions.



Switch to battery power, ha, ha - just kidding!


With two bad joints the fix is easy since the loco will stop when it hits the dead track section so you know exactly where one bad joint is.
Best is just to make sure you have solid electrical connections at the rail joints so you never run into that problem.
Bigger issue with brass track imho is power pickup from the track.


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## Dan Pierce (Jan 2, 2008)

Problem with loops is when a section is dead, there are 2 bad joints!!


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## toddalin (Jan 4, 2008)

Treeman said:


> You are depending on the connection at every piece of rail. With a length of wire you have one connection.


No, you were and I was just following your lead.

To quote: "The failure would be joints from rail to rail. I usally suggest running a feed to the far point of your layout."

So you are proposing just one feed to the far side and the near side is dependant "on the connection at every piece of rail."

Personally, my railroad is separated into 23 blocks for ~600 feet of track and each block has a feed wire. In this way I can run seven trains simultaneously using one, two, or three "throttle packs" (AristoCraft Train Engineers with 24 volt 12.5 amp Meanwell supplies) just using simple track power.

Additionally, we run a common ground and there are 7 common ground wires spaced around the layout. Finally, every section of track that is not insulated has a 16 gauge jumper wire soldered directly to the rails.


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## fyrekop (Sep 20, 2011)

Rail joiners are a major factor. SplitJaw claps with conductive grease are working well.
Toddalin,That is a lot of wiring Going DCC so I get by with a lot less.


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## toddalin (Jan 4, 2008)

fyrekop said:


> Rail joiners are a major factor. SplitJaw claps with conductive grease are working well.
> Toddalin,That is a lot of wiring Going DCC so I get by with a lot less.


>1/3 - <1/2 mile if laid end-to-end.

The common ground saves almost half of the wiring and is used for the trains, all lighting, and all accessories and electronics.

All rail feeders use 14 gauge and accessories (e.g., 21 turn-outs, lighting, etc.) use 16 gauge. All tracks use 16 gauge jumpers soldered to the rails.

All turnouts and accessories only need _1 wire_ because the second wire (common ground) picks up off the adjacent track section.


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