Why do I need 18 guage wire for feeder's?

[Don Gibson]

Why do I need 18 guage wire for feeder's?

I am running short duration 12 volt's @ 1.5 amp's (max) and with only 3"-4" short run's to the Buss, WHY won't 22 guage do as well? It's easier to work with.

It also fit's through solder eyelet's of mini toggle's, relay's, etc.

[howmus]

I think given the specs you have quoted, the 22 guage should work just fine. You didn't list the usage for these runs, but I don't think you would run into any trouble. I am assuming 12 v DC? I wired my entire DC layout (old) using 22 or smaller wire with no problem whatsoever.

[rrinker]

Simple - you DON'T. I use #22 myself, it was conveniently available in large spools at Home Depot in the same colors I used for my #12 bus wire.

#22 is FINE for track feeders.


--Randy

[Rotorranch]

Personally , IMHO, bigger is better!

Use the biggest wire available for your application!

The point I'm trying to impress is, 22 gauge solid wire breaks way easier than 18 ga stranded!!!

For under table use, use heavy gauge, and use it as taps. Run lighter gauge feeds to the track.

Buss wire anything you can with "oversize" wire undertable....it'll make it far more reliable!

Rotor

]

[Blind Bruce]

Don,
There might be a difference between "track feeders" and the use of wire in toggle switches etc. A toggle switch may involve longer than 4" runs. As the resistance increases with each length of wire, a longer run might drop more voltage than you have to spare. And remember, twenty lengths of 4" wire connected in series, is still 80" of resistance. For example, if you run 4" wires to a toggle switch, then on to a track rail, the resistance adds up.
Keep the short feeds to the rails small, but everything else should be as large as practical.
BB

[Anonymous]

18 gauge? Is that all? I'm using 12 gauge bare copper ground wire for my bus. Using bare wire is much easier to just solder directly to, without having to strip insulation off every few feet.

QUOTE: Originally posted by Don Gibson

Why do I need 18 guage wire for feeder's?

I am running short duration 12 volt's @ 1.5 amp's (max) and with only 3"-4" short run's to the Buss, WHY won't 22 guage do as well? It's easier to work with.

It also fit's through solder eyelet's of mini toggle's, relay's, etc.

[AntonioFP45]

I'm electronically challenged, but does not wire that is thicker offer less resistence in DC applications?

[grayfox1119]

Yes it does Antonio. Resistance is a function of the both the material and the cross sectional area. The larger the wire diameter, the lower the resistance. And, resistance is higher also with temperature increase. If you had wire at 0 degrees Kelvin, the reistance of any wire would be 0 ohms. But that is REAL cold, we don't want to go there for MRR.
I will be using #12 gauge wire for the main buss under the tables, and #14 gauge wire for feeders to the tracks. Both will be SOLID wire. You can use STRANDED if you desire, or, if you feel the wire/s will be moved around a lot, as stranded wire can take much more flexing than solid wire before breaking, especially small gauge wire like #16 up through #24 gauge. I will be using European style Barrier Strips for all buss runs and tap offs for track feeders. No soldering involved, and these connectors are excellent for conductivity and connectivity, and make additions, deletions, and troubleshooting MUCH easier. Soldering is the ultimate of course, but I have used these barrier strips for many years, and they are fool-proof, all you need to do is make sure you tighten down well on the screw and you are "golden".

[tsasala]

14 gauge for feeders? Seems like over kill to me. I have feeder every few feet and they are 22 AWG. I can't imagine the trouble of solder and then trying to cover up 14 gauge feeders.

-Tom

[grayfox1119]

You run the feeders down through a hole under the track in the sub base, you never see them. And #14 wire is not that bad to solder to rails if you have any soldering skills at all. A little practice and you will soon be just fine soldering #14. For DC only, don't worry about running #14, but for DCC, you have a PULSED signal, which means it will have a frequency. This is a whole new ballgame from DC, but not that difficult to understand at all, don't get bothered by it if you are electronically challenged, you can do it. Resistance, and capacitance, and inductance all will now play a role in signal strength. You really want to keep resistance to a minimum, so #12 gauge for a Main buss, and #14 gauge for the track feeders is what we should be running. Can you get by with less? This will depend upon the size of your layout. If you have a small layout, you can get away with smaller gauge wire.

[rrinker]

#14? Maybe for O scale, or G, where you really need the power. But then, unless the run is short, #12 is probably too small for the bus and a better combination might be #10 bus with #14 feeders.

Definitely overkill for the feeders in HO and smaller. The voltage drop for 6" of #22 from the big #12 bus to the track is negligible. Plus if you put in enough feeders - that's a lot of wire essentially in parallel, which equates to fewer but larger feeders. #14 wire is bigger than the web of code 83 HO rail. Sure you can solder it on, but it's not gonna look too neat no matter how good you are at soldering, simply because of the bulk.

I test ran my layout with a pair of clip leads that were maybe #20 wire clipped to the output of my booster and to a single pair of #22 feeders. For an 8x12 layout with a bunch of turnouts (joints not soldered - joints between two sections of flex ont he curves WERE soldered). I got no slowdowns, no flickering headlights. Didn't stop me from installing the #12 bus and soldering all the feeders to it, but the point is it DID work fine with way underdesigned wiring. My #12 bus and feeders at every section of track (even short 'filler' pieces) is probably overkill too as far as number of feeders is concerned, but since it only takes a minute to strip and solder each pair, it's no big deal.

--Randy

[Adelie]

The only feeders I ran that were 18 guage were about 10' long and ran from a DCC block occupancy detector to a detection block. For normal lengths, I use either 20 or 22, whatever I have on hand.

[grayfox1119]

Go to this web site guys, and then lets discuss the pros and cons. This is the best, most authoritative info that I have found anywhere.

http://www.wiringfordcc.com/track_2.htm

[howmus]

QUOTE: Originally posted by grayfox1119

Go to this web site guys, and then lets discuss the pros and cons. This is the best, most authoritative info that I have found anywhere.

http://www.wiringfordcc.com/track_2.htm

grayfox, Alan Gartner says to use #20 to #24 for track feeders in HO.
"I find 20 AWG solid makes great feeders stripped from thermostat wire cables for HO. It tucks nicely along the outside of the rail. If you attach a wire to every 3' (1m) section of track, you can use wire as small as 24 AWG. Here are my suggestions. There are no hard and fast rules about the wire size you should use. Try to keep your feeders to about 6" in length or less - especially if you are using the smaller sizes of wires I suggest for your scale. When using the larger sizes suggested for your scale, try to keep your feeders to about 12" in length or less.

Scale
Suggested Wire Sizes AWG(mm)

Smallest Largest
Z
24 (.511) 22 (.645)
N
24 (.511) 22 (.645)
HO
24 (.511) 20 (.813)
S,O
22 (.645) 16 (1.290)
G
20 (.813) 14 (1.628)"

#14 is very much overkill and certainly obtrusive on HO track. I have used #18 for track feeders where it is hidden. Unless you are in G Scale nothing will be gained by using that large wireing for feeders.

[Don Gibson]

Greyfox

The Website you recommended say's "feeder's 20g - 22g are adequate. Considering the low voltage, current, and short feeder length's (ahem), one doen't REQUIRE even 18 guage..

I read your description: "Antonio. Resistance is a function of the both the material and the cross sectional area. The larger the wire diameter, the lower the resistance. And, resistance is higher also with temperature increase"

- all true, but doens't 'resistance' (or is it 'impedance') that increases with a length component? It shows up as a 'per foot voltage loss. Thank's for everybody's input.

[grayfox1119]

You didn't read the whole article, he goes on to say that he uses #12 for buss and #14 for feeder on his HO....

As for resistance, yes, it does increase with length, that is why they spec it per 1000 feet in manuals, but you can extrapolate to find the resistance per foot, and the figure how much your layout will have cold. As the buss, feeders, tracks heat up with actually running conditions, the resistance will rise causing a greater voltage drop. Granted we are not talking about huge voltage drops here, but with DCC you really want to have the best possible signal at the decoder/s. This is a very good discussion guys, that is why I love this forum.

[howmus]

Not to disagree here grayfox, but...... Alan uses #14 for his Sub Bus wiring not for feeders. I use #12 for my main bus, #16 for my sub bus network, and 18 to 24 for track feeders. He uses #14 for track feeders on his Garden RR.

Don asked: "Why do I need 18 guage wire for feeder's?

I am running short duration 12 volt's @ 1.5 amp's (max) and with only 3"-4" short run's to the Buss, WHY won't 22 guage do as well? It's easier to work with.

It also fit's through solder eyelet's of mini toggle's, relay's, etc."

Our replys were correct for that question. He was not asking about track wiring. For short duration 12volt @ 1.5 amps, he will not have a problem with #22 wire.

[Anonymous]

Well yall can toss it back and forth all you want. I'm using 12 gauge solid bare copper wire for my bus, and 20 gauge solid copper feeders. I only wanna do it once.

[AntonioFP45]

Great info guys!

Thanks very much for your input.

I still am leaning towards the school of "thicker is better and more durable".

I've been reading about DCC applications and from what I gathered the lower the resistence in power and track circuits, the better.

I''ll likely go with #14 for a main buss. For feeders #16 or #18 (depending on how easy it is for me to solder). I get excellent discounts from industrial vendors, so the price of electrical wire is non-issue.

[rrinker]

How long will that bus run be? If it's about 20 feet, #14 should be fine. Much longer and I'd say go wit #12 for the bus instead of #14.

[grayfox1119]

And don't forget, it is just not one way for length. You have to take into account for TOTAL length, the feed and the return. So if you run out say 20 feet, and then return, you have 40 feet of length. Trust me, if you have a large layout like that or larger, use #12 for Main buss, and don't go smaller then #16 for track feeders. If you think you cannot solder to #14 ( or #16 for that matter ), take a section of track to use for practice, until you feel confident.

[jfugate]

I prefer stranded wire for most applications because it's more flexible ... I use 12 guage stranded for my bus, and 18 guage for feeders. Some of my feeders get up to 3 feet long, so I prefer something heavier than 22 or 20 guage.

The trick is how to solder the feeders to the rails so they don't look darn ugly when the wire guage is that large.

What I do is solder them to the *back sides" of both rails, so they don't even show. I explain how I do this in my FORUM CLINIC on DCC and things electrical:
http://www.trains.com/community/forum/topic.asp?page=4&TOPIC_ID=36389


Soldering large guage stranded wire feeders to the *backsides* of the rails


Closeup of the feeders soldered to the backsides of the rails

See this thread for all the how-to details (scroll down about half way): http://www.trains.com/community/forum/topic.asp?page=4&TOPIC_ID=36389

[Mark300]

QUOTE: Originally posted by jfugate

The trick is how to solder the feeders to the rails so they don't look darn ugly when the wire guage is that large.

Joe....

That technique is d_m clever!

Regards,

Mark

[grayfox1119]

Joe, I take it you have had no problems with running DCC over greater lengths ( HO Gauge) with #18 gauge wire for track feeders? Some as long as 3 feet?

[jfugate]

***:

Not a problem with 18 guage feeders ... I also install feeders every 3 feet (more or less).

18 guage copper wire 3 feet long has much less ohms per foot than code 83, 70, or 55 Nickel Silver rail, and that's what really matters, I think.

[emdgp92]

I have an 14 gauge power bus, with 18 gauge feeders. So far, I haven't noticed any problems. I could have used smaller wire, but then I wouldn't have been able to use those nifty suitcase connectors.

[rrinker]

Voltage drop is proportional to distance AND current - so if you have feeders to each section of track, even running 3-unit consists, there won;t be that much current through any one feeder. 3 units on one section of track - 2 pair of feeders going to is. The end result is half the ohms per foot of a single stranfd of the same wire guage. That effectively makes 2 pair of #20 feeders the same as a single #16 feeder. In Joe's case = 3 feet of #18, which is 6 total feet of #18 wire, even with the FULL FIVE AMPS of the booster being pulled through it, will only drop 0.18 volts. LESS THAN 1/4 of a volt! Completely not noticeable. The same length of #20 wire would only drop .3 volt, again negligible. My feeders are under a foot. Total of 2 feet of wire, with #22 that's a .16 volt drop AT 5 amps - which isn't even possible in my system today since I only have the Zephyr which is 2.5 amps. Those are the worst case numbers for a single feeder pair. Since there is power at each end of the section, unless a joint fails, normally the drop is half that!
I hate to pull out the EE math, but that information too is on Allen's web site. If you can get #16 wire for free, and can solder on the back side like Joe does (kind of hard on an around the walls narrow shelf layout - plus be careful on the near rail to file down the joint so that it doesn't interfere with wheel flanges), more power to you. But it is DEFINITELY overkill for feeders. The bigger size is far more critical for the bus - even #12 over 30 feet with a 5 amp load is going to drop almost half a volt. A 50 foot run of #10 is also a half volt at 5 amps. The question becomes, how much drop can you tolerate before it becomes noticeable? A half a volt or less certainly is not going to be noticeable. Probably a whole volt isn't very noticeable either.

--Randy

[jfugate]

QUOTE: Originally posted by emdgp92

I have an 14 gauge power bus, with 18 gauge feeders. So far, I haven't noticed any problems. I could have used smaller wire, but then I wouldn't have been able to use those nifty suitcase connectors.

Randy's post aptly explains how 18 guage feeders are probably a bit of overkill, but then there are the practicalities of things like the suitcase connectors. I too, use 18 guage feeders also because they work great with the more inexpensive suitcase connectors.

Maybe a bit of overkill, but then I never worry about using a really long feeder somewhere when I need to. I probably even have a few 4 footers on the layout in a couple of places ... I don't measure them precisely.

[Anonymous]

I used 14 bus and 22 track feeders coming off of it. Bigger is better, and not much more expensive, especially if you buy in big rolls.

[Anonymous]

Just a question here, Joe.....how is this done using Kato Unitrack?

QUOTE: Originally posted by jfugate

I prefer stranded wire for most applications because it's more flexible ... I use 12 guage stranded for my bus, and 18 guage for feeders. Some of my feeders get up to 3 feet long, so I prefer something heavier than 22 or 20 guage.

The trick is how to solder the feeders to the rails so they don't look darn ugly when the wire guage is that large.

What I do is solder them to the *back sides" of both rails, so they don't even show. I explain how I do this in my FORUM CLINIC on DCC and things electrical:
http://www.trains.com/community/forum/topic.asp?page=4&TOPIC_ID=36389


Soldering large guage stranded wire feeders to the *backsides* of the rails


Closeup of the feeders soldered to the backsides of the rails

See this thread for all the how-to details (scroll down about half way): http://www.trains.com/community/forum/topic.asp?page=4&TOPIC_ID=36389