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what is considered a "run"?

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rda
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what is considered a "run"?
Posted by rda on Monday, February 3, 2020 2:19 PM

looking for wiring info and it refers to putting feeders for each run. thanks

 

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Posted by BigDaddy on Monday, February 3, 2020 5:42 PM

Welcome to the forum.  Your post are delayed while you are in moderation.  It keeps Borat and his sister out of the forum.

The more specific you can make your title (and this one is fine) and the more information you can give us, the better answers you will get.

rda
and it refers to putting feeders for each run.

Don't know anyone in the forum named 'IT' nor how they define a the length of a run. 

DCC, if that is what you are building, is more demanding than DC.  Rail joiners, especially after weathering, and painting and wear and tear can be unreliable conductors of electricity.  

I'm not sure where this rule of thumb came from, but a feeder every 6' and every piece of track having a solder connection to the next rail or a feeder.  As one of our gurus said recently, you can't have too many feeders but you can have too few.

Too few can make circuit breakers unreliable, lead to poor running on the layout.

Turnouts are another variable.  Some require insulated joiners.  That means the rail beyond the turnout needs a feeder.  It gets more complicated that that in that power in the turnout may depend on contact of the point to stock rails.  There are some that advocate 6 wires to every turnout.

Henry

COB Potomac & Northern

Shenandoah Valley

rda
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Posted by rda on Tuesday, February 4, 2020 9:56 AM

that's for the reply, but still don't understand what is meant by a "run". Is a run simple the entire track? is it turnout to turnout?

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Posted by Onewolf on Tuesday, February 4, 2020 10:40 AM

We need more context to answer your question.  Can you provide more details about what you are asking about?

Modeling an HO gauge freelance version of the Union Pacific Oregon Short Line and the Utah Railway around 1957 in a world where Pirates from the Great Salt Lake founded Ogden, UT.

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Posted by doctorwayne on Tuesday, February 4, 2020 11:10 AM

Well, I'm certainly no DCC guy, nor do I use more than two wires from my power source to the entire layout.

However, I'd guess a "run" to be simply a length of bus wire (nothing to do with Greyhound) to a section of one's layout.  A "run" doesn't specify a distance, so it would likely be whatever length is needed for your particular track plan.

It's pretty simple, I think:  when you wire a house, you "run" wires to the various rooms, just as you run wires to the various parts of your layout.  In-turn, the "feeders" run power to the rails.  No need to over-complicate things here.

Wayne

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Posted by mbinsewi on Tuesday, February 4, 2020 11:24 AM

Maybe he's referring to something in electricians "speek" as to a "home run" where the wire from a circuit goes directly to the main panel.

Example:  A series of receptacles in a kitchen.  The wire that feeds the receptacles, from the main panel to the first receptacle box, is the home run.

So, in terms of wiring a layout, using a bus with feeders, and dividing the layout into seperate power/control blocks, the bus from each block going back to the main power supply, could be considered a home run.

I dunno, just a quess? 

Mike.

rda
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Posted by rda on Tuesday, February 4, 2020 3:54 PM

hang tight; i'll find an example of what i'm referring to.  thanks

 

rda
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Posted by rda on Tuesday, February 4, 2020 3:59 PM

ok, here's an example of article I was looking at:

"The length of the run required is also a key factor in determining a proper bus size. Shorter runs will experience less voltage drop and can employ smaller wire. Generally, No. 12 to No. 14 wire is ideal for bus wiring in most scales. For feeders, No. 18 to No. 24 can be used. Since the feeders must be attached to the rails directly, size is a factor in smaller scales."

So, again, what is determined as a 'run'?

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Posted by SeeYou190 on Tuesday, February 4, 2020 4:41 PM

From that quote it sounds like the run is the total length of the layout from one point (beginning) to the other (end of run).

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-Kevin

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Posted by maxman on Tuesday, February 4, 2020 5:40 PM

rda

ok, here's an example of article I was looking at:

"The length of the run required is also a key factor in determining a proper bus size. Shorter runs will experience less voltage drop and can employ smaller wire. Generally, No. 12 to No. 14 wire is ideal for bus wiring in most scales. For feeders, No. 18 to No. 24 can be used. Since the feeders must be attached to the rails directly, size is a factor in smaller scales."

So, again, what is determined as a 'run'?

 

This is being made more complicated than it needs to be.

Assume that you have a point A and point B on the railroad.  The run is simply the length of a wire or bundle of wires to get from point A to point B.

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Posted by BigDaddy on Tuesday, February 4, 2020 6:14 PM

rda
ok, here's an example of article I was looking at: "The length of the run required is also a key factor in determining a proper bus size. Shorter runs will experience less voltage drop and can employ smaller wire. Generally, No. 12 to No. 14 wire is ideal for bus wiring in most scales. For feeders, No. 18 to No. 24 can be used. Since the feeders must be attached to the rails directly, size is a factor in smaller scales." So, again, what is determined as a 'run'?

This is something one would write about if discussing DCC, so we will go with that.

A run is length of the bus that follows your track underneath the layout.  That could be a tiny dioramma or it could Howard Zane's 2800 square foot layout.   The bus can also have a branch, called a sub bus that would feed a yard.

1/3 down the page is a chart based on scale and distance

https://dccwiki.com/Wire_Sizes_and_Spacing

As I hinted at earlier, voltage can drop off with the further it travels down the bus.  Hence larger gauge wire is needed.  Solid wire especially 12 ga is cumbersome to bend.  For track feeders, you want solid wire and if it is a short run to the bus, 22 or 20 ga is adequate.

Henry

COB Potomac & Northern

Shenandoah Valley

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Posted by davidmurray on Tuesday, February 4, 2020 8:08 PM

rda:

To my way of thinking:

You could have your power supply centred on a wall.  Two wires going to the left for 25'  would be a run.  Two wires going to the right for 40' would be a different run.    Two more wires going six feet to the right and then 19' down a peninsula would be a third run. 

As noted there are recommended practices for various lengths of run.  Circuit breaker for each run!

If I am wrong, someone will gladly correct me.

Dave

 

David Murray from Oshawa, Ontario Canada
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Posted by mbinsewi on Tuesday, February 4, 2020 8:16 PM

rda
"The length of the run required is also a key factor in determining a proper bus size. Shorter runs will experience less voltage drop and can employ smaller wire

As others have pointed out, the "run" is the distance from the power supply to the farthest track.  Your power supply can be in the middle, with equal "runs" in each direction, or it can be on one end or the other, making the "run" longer, and wire size adjustments may have to be made, as the article you refferenced points out.

Mike.

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Posted by Track fiddler on Tuesday, February 4, 2020 8:29 PM

A run is considered when it's your turn to get the mail

It's just too darn cold out in Minnesota

When it's my turn to get mail  I run out and run back quick

I hate when it's my turn to get the mail

 

 

TF

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Posted by mbinsewi on Tuesday, February 4, 2020 8:34 PM

OR, when someone needs to make a:  "B double e double r un, beerrun" as sung by Todd Snider:

Mike.

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Posted by Track fiddler on Tuesday, February 4, 2020 8:57 PM

Thanks Mike for keeping me in check

I don't think I'll need a beer run till Friday

Wednesday would be nice but I got to wxxk the rest of the weekLaugh

 

 

TF

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Posted by selector on Wednesday, February 5, 2020 11:42 AM

Run = Distance (or length)

Run of trackage, run of bus wires, run of sub-bus...

In the context you cited, they're worried that, depending on the type of wire used as a bus, you'll experience X voltage loss the further it must travel down that wire. For 14 gauge wall wire in home construction, you'd not have to worry for at least 20 feet, and even then it would be minimal.

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Posted by BATMAN on Wednesday, February 5, 2020 12:04 PM

The power comes from my DCC power source to this terminal strip. From there, there are six runs that go down this 18' bench like fingers.

Two go down each side to power the mainline tracks, one powers the yard and the other powers the turntable. 

I just attach the last track feeder to the end of the buss wire, then I don't have to have a discussion on what to do with the end of the buss wire.

It is overkill on the wiring but I had 600' of 12g wire so why not.Laugh

 

Brent

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Posted by riogrande5761 on Wednesday, February 5, 2020 1:43 PM

selector
In the context you cited, they're worried that, depending on the type of wire used as a bus, you'll experience X voltage loss the further it must travel down that wire. For 14 gauge wall wire in home construction, you'd not have to worry for at least 20 feet, and even then it would be minimal.

AWG 14 home (rated for 15 amp) wire surely is strung way more than 20 feet in most homes.  What would be a reasonable maximum run of 14 AWG if used on a model RR DCC bus?

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by SeeYou190 on Wednesday, February 5, 2020 4:42 PM

riogrande5761
What would be a reasonable maximum run of 14 AWG if used on a model RR DCC bus?

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For Model Railroad bus and Speaker Wire, I consider #10 the minimum wire size.

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-Kevin

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Posted by riogrande5761 on Wednesday, February 5, 2020 4:47 PM

Sure.  What would others suggest.

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by ATLANTIC CENTRAL on Wednesday, February 5, 2020 4:59 PM

mbinsewi

OR, when someone needs to make a:  "B double e double r un, beerrun" as sung by Todd Snider:

Mike.

 

I love that guy, and that song, and I don't even drink beer........

Sheldon

    

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Posted by BATMAN on Wednesday, February 5, 2020 5:02 PM

There are voltage dropoff charts online. I would think you would have to go a very, very long way to be worried about using 14g wire. 

I only used 12g because I got it for a song. I went to the industrial electric shop and asked for 14g and the guy asked if I could use 12g instead for about a tenth of the price. He gave me the wire off two of those 5' spools just so he could hang new spools for the next days rush. I think I ended up with about 600' as he just peeled off what was left. Timing is everything.Laugh

Brent

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Posted by mbinsewi on Wednesday, February 5, 2020 5:05 PM

I used 14ga. on my bus, and I even twisted the black and red together to make it easier to handle.  I haven't had any problems, but I have a small layout, about 50' main line run, "L" shaped dog bone. 

Power supply is close to the middle, I did it in blocks, to use DC to start with, Didn't use common rail, isolated each rail at blocks.

Made it easy to go to DCC.  Just unhook the DC pack and hook up the DCC power.

I think I used 20 or 22 ga for feeders.

Mike.

rda
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Posted by rda on Wednesday, February 5, 2020 5:07 PM

got it, thanks. ok, the run refers to the wiring, not a section of the track

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Posted by SeeYou190 on Wednesday, February 5, 2020 6:22 PM

ATLANTIC CENTRAL
I love that guy, and that song, and I don't even drink beer.......

.

That is much better than Garth Brooks' version.

.

-Kevin

.

Living the dream.

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Posted by selector on Wednesday, February 5, 2020 6:51 PM

riogrande5761

 

 
selector
In the context you cited, they're worried that, depending on the type of wire used as a bus, you'll experience X voltage loss the further it must travel down that wire. For 14 gauge wall wire in home construction, you'd not have to worry for at least 20 feet, and even then it would be minimal.

 

AWG 14 home (rated for 15 amp) wire surely is strung way more than 20 feet in most homes.  What would be a reasonable maximum run of 14 AWG if used on a model RR DCC bus?

 

It depends on your tolerance for voltage drop over distance with a nominal voltage of 15, 5 amps (in my case), and with a specific distance in mind, single phase, race run, copper wire.  I asked the calculator I used for no more than a 4% drop in voltage over 20 feet, and the result was 14 gauge.

http://wiresizecalculator.net/

 

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Posted by ATLANTIC CENTRAL on Wednesday, February 5, 2020 7:18 PM

SeeYou190

 

 
ATLANTIC CENTRAL
I love that guy, and that song, and I don't even drink beer.......

 

.

That is much better than Garth Brooks' version.

.

-Kevin

.

 

While similar, they are actually different songs.

Todd snider wrote his song, the Garth song was written by Kent Blazy, Kim Williams, Amanda Williams, Keith Anderson, and George Ducas.

Sheldon

    

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Posted by mbinsewi on Wednesday, February 5, 2020 7:37 PM

Todd's one of my favorites.  Without buying his music, I only hear him on Sirius XM Outlaw Country.  He's also made a few appearances on the Bob and Tom radio show,

He does, sometimes, provoke some controversy in his music, but don't they all?

I've only heard his version of his song.

I guess we've covered the OP's question on what is a "run".  I thought it was pretty obvious.

Mike.

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Posted by SeeYou190 on Thursday, February 6, 2020 6:16 AM

ATLANTIC CENTRAL
While similar, they are actually different songs.

.

OK. I thought it might be like Louie Louie, where there are seriously drastic differences from some versions to others, but they are considered the same song.

.

-Kevin

.

Living the dream.

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