Power Buss Wiring using Speaker Wire vs Individual Wires Twisted together for long runs


Bob Lessig
 

Are there any pros or cons for using Speaker Wire vs using individual wires twisted together, 3 turns per foot, for long runs of your power busses.  These would not be the Power Buss wires that track feeders attach to.  It would be the main power buss runs to get power to the actual power busses that run under the track that the track feeders really attach too.

Thanks,


Daniel Brewer
 
Edited

Hi Bob,

I'm using 12 AWG AudioPipe speaker wire for the main bus, and each industrial area gets the same brand in 14AWG. I ran this by NCE and they said it would work fine if my buss runs weren't too long. Most of mine are about 30'. Some wiring examples are below. I don't do soldering below the deck but have opted to use the connectors pictured as well as Wago Connectors for feeder wires.

Have fun!

Dan
https://www.amazon.com/Audiopipe-Gauge-Stranded-Conductor-Speaker/dp/B00J35M2B8/ref=sr_1_6?crid=11XCO31W1BA48&keywords=audiopipe+12+awg+wire&qid=1649682697&sprefix=audiopipe+12+awg+wire%2Caps%2C88&sr=8-6




Daniel Brewer
 

Sorry, it seems my pics didn't make the trip....


Jim Betz
 

Bob,
  When you twist speaker wire the two wires are still running parallel to each other
and the twist does not do what a twisted pair does.  Speaker wire is normally 
considerably smaller than the recommended gauge for bus runs.  The best (least
trouble free) wire for just about any layout over the proverbial 4x8 is at least 14g
wire - that is twisted 3 to 4 times per foot.  I prefer/use solid - many use stranded.
  I buy my 14g (or larger) in 100 or 500 foot spools at the big box store and it isn't
that much more than Romex (which has an extra wire - the ground - and needs 
to have the outside insulation stripped off).
                                                                                              - Jim in the PNW


John Bishop
 

We have used 12 gauge speaker wire (with Anderson connectors) to connect the buses between our O scale modules for many years. Not twisted. Works fine.

John Bishop

On Monday, April 11, 2022, 07:58:57 AM PDT, Jim Betz <jimbetz@...> wrote:


Bob,
  When you twist speaker wire the two wires are still running parallel to each other
and the twist does not do what a twisted pair does.  Speaker wire is normally 
considerably smaller than the recommended gauge for bus runs.  The best (least
trouble free) wire for just about any layout over the proverbial 4x8 is at least 14g
wire - that is twisted 3 to 4 times per foot.  I prefer/use solid - many use stranded.
  I buy my 14g (or larger) in 100 or 500 foot spools at the big box store and it isn't
that much more than Romex (which has an extra wire - the ground - and needs 
to have the outside insulation stripped off).
                                                                                              - Jim in the PNW


Alexander Wood
 

Bob,

From everything I've heard, the twisted bus wires are just to get them close to each other- the twist itself doesn't actually do anything, so speaker wire or zip cord that's 14ga or larger is ideal for DCC bus runs. For modular applications, PowerWerx has red/black zip cord so it's easy to keep the "polarity" correct.

Alex

On Sun, Apr 10, 2022 at 2:59 PM Bob Lessig <boblessig@...> wrote:
Are there any pros or cons for using Speaker Wire vs using individual wires twisted together, 3 turns per foot, for long runs of your power busses.  These would not be the Power Buss wires that track feeders attach to.  It would be the main power buss runs to get power to the actual power busses that run under the track that the track feeders really attach too.

Thanks,



--

Alexander Wood

Hartford-New Haven, CT

Modeling the modern era freelanced G&W Connecticut Northern in HO

Digikeijs DR5000 - JMRI - ProtoThrottle - TCS UWT-100 - TCS UWT-50p - Digitrax Simplex


Steve Haas
 

“From everything I've heard, the twisted bus wires are just to get them close to each other- the twist itself doesn't actually do anything, so speaker wire or zip cord that's 14ga or larger is ideal for DCC bus runs. For modular applications, PowerWerx has red/black zip cord so it's easy to keep the "polarity" correct.”

 

While a benefit of twisting the wire pairs is to keep them organized, close, and not taking up any more real estate under the layout, the recommendation to twist them comes from experts and professionals who understand _all_ the ins and outs of power and data transmission, not only in model railroading, but out in the real world.

 

Those buses radiate a fair amount of energy, and when there is noise on the bus that too is radiated out.  Those rogue signals can corrupt other data signals.  Keeping the bus pair as close as possible actually cancels out this noise.  The closer the pair of wires are to each other the better they cancel each other out.

 

Using zip cord and speaker wire serves to keep wire _fairly_ close, but not as close as twisting the individual wires.  Twisting zip cord or speaker wire _is wasted effort_ as the distance between the two wires in the cord is defined by the cord itself – twisting doesn’t decrease that separation.

 

I used “noise” above because I’m _NOT_ a power or signal transmission specialist, and every time I try to be more specific than “noise” I get part of it wrong and get corrected by the Pros <GRIN>!

 

For better, accurate descriptions look at WWW.wiringforDCC.com.  A specific page where this is discussed is at: https://wiringfordcc.com/intro2dcc.htm#a4 in the second paragraph. 

 

Another discussion on this topic can be located on Marcus Amman’s website:  http://www.members.optusnet.com.au/nswmn2/DCC.htm# specifically at: http://www.members.optusnet.com.au/nswmn2/DCC.htm#Twist.

 

A Google search for “Power Transmission Radiation” or something similar would also yield good information.

 

Best regards,

 

Steve

 

Steve Haas

Snoqualmie, WA

 

 

 

 

 

 

 

 

 

 

 

Alex

 

On Sun, Apr 10, 2022 at 2:59 PM Bob Lessig <boblessig@...> wrote:

Are there any pros or cons for using Speaker Wire vs using individual wires twisted together, 3 turns per foot, for long runs of your power busses.  These would not be the Power Buss wires that track feeders attach to.  It would be the main power buss runs to get power to the actual power busses that run under the track that the track feeders really attach too.

Thanks,


 

--

Alexander Wood

Hartford-New Haven, CT

Modeling the modern era freelanced G&W Connecticut Northern in HO

Digikeijs DR5000 - JMRI - ProtoThrottle - TCS UWT-100 - TCS UWT-50p - Digitrax Simplex


Daniel Brewer
 

That is what I was told by NCE, John. I have great power to all tracks. I do run feeders to every piece of track.
Dan


Don Weigt
 

Twisting wire pairs has been used for much longer than DCC has been around. In audio work, it tends to cancel noise (any unwanted signals) coupling into one pair from the currents in others. It's great for minimizing hum and any stray signal pickup, including between multiple pairs close together..

Why? Because first one, then the other conductor (wire) is closer to the interference source, which may be other wiring, so the coupled signals are nearly equal in the two wires. For mics, speakers, and most any load, the current out in one wire is matched by the same current returning in the other wire. Twisting makes the coupled signals nearly equal and effectively opposite and cancelling. If not twisted, one wire is usually closer, and so gets a stronger signal coupled in, the effects in the two wires don't match, and "noise" is much more noticeable.





--
Don Weigt
Connecticut


Bob Lessig
 

Thanks for all the comments, guys.

The speaker wire or zip cord that I am thinking about is two twisted wires, rather than two solid wires.  They run as a pair of wires together in an insulating case where the two wires are run parallel the entire length of the wire cord.  Those two wires are placed within hundredths of an inch, or whatever the thickness of the insulations is between the 2 separate wires in that cord.

I would think that with the entire length of the cord, the two wires are kept parallel and the same distance apart, that this would work better or as good as twisting two separate wires together to reduce interference between the two wires in the cord. Or does the twisting of those two wires together make the difference?

I have noticed that when trying to twist two wires together that you cannot get them to touch together the entire length of the wire run.  That is why I would think that the parallel cords/wires that you can get would work just as good as twisting two separate wires together.

I know that you can get speaker wire/zip cord in 12 gauge. I think that the speaker wire/zip cord would be easier to string because it is twisted wire strands rather than solid.

These runs using this type of wire would not be used to hook track feeder wires to. They would be used to make a long run from the boosters/command station to get to a point on the layout where some of the individual circuit protections blocks would be split off and start their runs under those sections of track.  At that point I would use 14-gauge or 12-gauge solid wire depending on the length of run that would be needed.  They would be run parallel, about 4" apart under those sections of track that the feeder wires would actually be connected to.

I only have a couple of these runs to do to get to the power to the split-out points. I know that some of you will say to move the boosters closer but that will just move them further away from the other areas that those boosters serve. I don't really want to purchase 2 more boosters because I don't need the extra power in those districts.  They are just long runs.  This layout is 40' x 40' with about 350' of mainline running and two 30' staging areas.  Lots of long runs down 3 peninsulas, two wall runs, two 30' staging areas on lower level and two helixes to get to those staging areas.  I know that, if needed later, that I can add boosters to possibly get rid of those long buss runs if I run into power issue on those sections of the layout.

Thanks for listening.
Bob 


Don Vollrath
 

As Don W. has explained, twisting the pair of wires tends to reduce the effects of transmitted and received electrical and magnetic noise coupled to and from other wiring or objects. So even twisting zip-cord like speaker wire is better than just laying it next to other wiring. It doesn’t make any difference at the DCC frequencies of interest if the wires themselves are solid or stranded.

DonV


Alexander Wood
 

Bob,

While many will say that 30' from the booster is a rule of thumb, in practice, with good quality pure copper (not CCA) stranded wire, DCC signals can be pushed reliably over 100'. Your plan sounds pretty good with the ability to add boosters later if needed.

Alex

On Tue, Apr 12, 2022 at 4:32 PM Bob Lessig <boblessig@...> wrote:
Thanks for all the comments, guys.

The speaker wire or zip cord that I am thinking about is two twisted wires, rather than two solid wires.  They run as a pair of wires together in an insulating case where the two wires are run parallel the entire length of the wire cord.  Those two wires are placed within hundredths of an inch, or whatever the thickness of the insulations is between the 2 separate wires in that cord.

I would think that with the entire length of the cord, the two wires are kept parallel and the same distance apart, that this would work better or as good as twisting two separate wires together to reduce interference between the two wires in the cord. Or does the twisting of those two wires together make the difference?

I have noticed that when trying to twist two wires together that you cannot get them to touch together the entire length of the wire run.  That is why I would think that the parallel cords/wires that you can get would work just as good as twisting two separate wires together.

I know that you can get speaker wire/zip cord in 12 gauge. I think that the speaker wire/zip cord would be easier to string because it is twisted wire strands rather than solid.

These runs using this type of wire would not be used to hook track feeder wires to. They would be used to make a long run from the boosters/command station to get to a point on the layout where some of the individual circuit protections blocks would be split off and start their runs under those sections of track.  At that point I would use 14-gauge or 12-gauge solid wire depending on the length of run that would be needed.  They would be run parallel, about 4" apart under those sections of track that the feeder wires would actually be connected to.

I only have a couple of these runs to do to get to the power to the split-out points. I know that some of you will say to move the boosters closer but that will just move them further away from the other areas that those boosters serve. I don't really want to purchase 2 more boosters because I don't need the extra power in those districts.  They are just long runs.  This layout is 40' x 40' with about 350' of mainline running and two 30' staging areas.  Lots of long runs down 3 peninsulas, two wall runs, two 30' staging areas on lower level and two helixes to get to those staging areas.  I know that, if needed later, that I can add boosters to possibly get rid of those long buss runs if I run into power issue on those sections of the layout.

Thanks for listening.
Bob 



--

Alexander Wood

Hartford-New Haven, CT

Modeling the modern era freelanced G&W Connecticut Northern in HO

Digikeijs DR5000 - JMRI - ProtoThrottle - TCS UWT-100 - TCS UWT-50p - Digitrax Simplex


Nat Hill IV
 

Don V and Don W,

I have a question to either or both Dons.
What about the tracks themselves as sources of noise?  I'm confused as to why it is so important to have wires twisted, etc, when the blasted tracks are exactly the same distance apart and the inside rail is likely a lot shorter than the outside rail?
Not disputing any advice you've each given, and K fully intend to "twist the buss."
I absolutely appreciate your advice.

Nat Hill IV

On 4/13/2022 9:53 AM, Don Vollrath wrote:
As Don W. has explained, twisting the pair of wires tends to reduce the effects of transmitted and received electrical and magnetic noise coupled to and from other wiring or objects. So even twisting zip-cord like speaker wire is better than just laying it next to other wiring.  It doesn’t make any difference at the DCC frequencies of interest if the wires themselves are solid or stranded. 

DonV 




--
May the Good Lord take a likin' to ya' - Lester "Roadhog" Moran


Bob Lessig
 

Not to stir things up, but everything that I have heard or read over the years about twisting of the power bus wires was to keep "2 individual wires", used as a buss run, as close together as possible to reduce the interference between those two separate wires, which is what almost everyone uses on their layouts.  I have never read or heard that the wires need to be "twisted" to reduce the interference, just that they need to be kept as close together as possible.  I think that twisting 2 separate wires together was a way to keep them as close together as possible.  Thus, in zip cord wire, the 2 separate wires are kept at the same distance apart, and very close at that, the entire length of the run because of the insulation that surrounds them.  If the twisting is needed to reduce the interference between the 2 wires used for a power buss run, then I can understand that and definitely will do that.  I have just understood that those 2 wires need to be as close together as possible for the entire length of the run.


george hohon3
 

I really enjoy these types of threads and the various comments and opinions expressed.  After nearly 50 years of on again, off again model railroading, I have concluded that the vast majority of model railroaders will always have a better way to do anything involving the hobby.  Along with these various theories, and new and initiative ideas, a couple of common traits have been noticed . . . .
  • The first is the common failure to read the manual, where the vast majority of answers can be found on any given product, its installation and/or operation.  I'm guessing that posting questions here is based more on laziness than being confused with the manual?
  • The second is the common failure to contact the manufacturer directly.
  • And the third is trying to make the product due something it was NOT designed to do.
I've been operating my first (and probably my last) 12' x 36' DCC layout without any significant bus/feeder/reversing problems for over 15 years.  And I attribute that to simply following the manufacturer's manual and installation guidelines.

As for the discussion on wire size and placement, twisted or separated, I find it laughable and fascinating at the same time.  As for answers concerning wire sizes, placement, or run lengths, I would offer the following from my experiences . . . . stick with general, accepted practices and give yourself an extra 10% when in doubt.  This isn't rocket science.  Stop wasting your time beating this dead horse and get back to modeling/building something.

One last comment . . . . I installed individual 18-gauge bus wires, approximately 6" to 8" apart, and used a smaller gauge wire for my track feeders.  All wires were solid, no stranded at all.  All connections were made with "suitcase" clips using the correct gauge size and appropriate pliers.  My command station is located at a point that is approximately 40% and 60% of the over-all length of the layout.  I run 4 to 5 trains at a time on a double decked layout, with 9 protected blocks.  The layout is both HO and HOn3.

George     


From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of Bob Lessig <boblessig@...>
Sent: Wednesday, April 13, 2022 9:41 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: Re: [w4dccqa] Power Buss Wiring using Speaker Wire vs Individual Wires Twisted together for long runs
 
Not to stir things up, but everything that I have heard or read over the years about twisting of the power bus wires was to keep "2 individual wires", used as a buss run, as close together as possible to reduce the interference between those two separate wires, which is what almost everyone uses on their layouts.  I have never read or heard that the wires need to be "twisted" to reduce the interference, just that they need to be kept as close together as possible.  I think that twisting 2 separate wires together was a way to keep them as close together as possible.  Thus, in zip cord wire, the 2 separate wires are kept at the same distance apart, and very close at that, the entire length of the run because of the insulation that surrounds them.  If the twisting is needed to reduce the interference between the 2 wires used for a power buss run, then I can understand that and definitely will do that.  I have just understood that those 2 wires need to be as close together as possible for the entire length of the run.


Don Weigt
 

Bob L,

This isn't about stranded vs solid conductors. Nor is it about coupling between the two wires in a pair. The twisting of the pair around each other helps reduce coupling of signals from that pair into or from other nearby wiring. Most of the time, you won't detect any difference on your railroad without specialized test equipment, such as an oscilloscope. But, for the unlucky few, the problems can be bedeviling.

You can help avoid problems by routing your DCC wiring runs a few inches or more from any other signal wiring. Someone has mentioned here that they had to separate some of their wiring between blocks and occupancy detectors to prevent false occupancy indications, because pulsing currents in one wire will couple inductively (magnetically) and capacitively into other nearby wires. The closer the spacing and the longer the parallel runs, the greater the likelihood of problems. It's the parallelism that causes the coupling. Wires crossing at right angles couple next to nothing between them.


--
Don Weigt
Connecticut


Alexander Wood
 

Steve,

Based on my experience twisting bus wires, the zip cord would actually put the two conductors as close or closer together than twisting individual wires. Maybe that's just due to the particular type of wire I'm trying to twist.

Alex

On Mon, Apr 11, 2022 at 9:55 PM Steve Haas <Goatfisher2@...> wrote:

“From everything I've heard, the twisted bus wires are just to get them close to each other- the twist itself doesn't actually do anything, so speaker wire or zip cord that's 14ga or larger is ideal for DCC bus runs. For modular applications, PowerWerx has red/black zip cord so it's easy to keep the "polarity" correct.”

 

While a benefit of twisting the wire pairs is to keep them organized, close, and not taking up any more real estate under the layout, the recommendation to twist them comes from experts and professionals who understand _all_ the ins and outs of power and data transmission, not only in model railroading, but out in the real world.

 

Those buses radiate a fair amount of energy, and when there is noise on the bus that too is radiated out.  Those rogue signals can corrupt other data signals.  Keeping the bus pair as close as possible actually cancels out this noise.  The closer the pair of wires are to each other the better they cancel each other out.

 

Using zip cord and speaker wire serves to keep wire _fairly_ close, but not as close as twisting the individual wires.  Twisting zip cord or speaker wire _is wasted effort_ as the distance between the two wires in the cord is defined by the cord itself – twisting doesn’t decrease that separation.

 

I used “noise” above because I’m _NOT_ a power or signal transmission specialist, and every time I try to be more specific than “noise” I get part of it wrong and get corrected by the Pros <GRIN>!

 

For better, accurate descriptions look at WWW.wiringforDCC.com.  A specific page where this is discussed is at: https://wiringfordcc.com/intro2dcc.htm#a4 in the second paragraph. 

 

Another discussion on this topic can be located on Marcus Amman’s website:  http://www.members.optusnet.com.au/nswmn2/DCC.htm# specifically at: http://www.members.optusnet.com.au/nswmn2/DCC.htm#Twist.

 

A Google search for “Power Transmission Radiation” or something similar would also yield good information.

 

Best regards,

 

Steve

 

Steve Haas

Snoqualmie, WA

 

 

 

 

 

 

 

 

 

 

 

Alex

 

On Sun, Apr 10, 2022 at 2:59 PM Bob Lessig <boblessig@...> wrote:

Are there any pros or cons for using Speaker Wire vs using individual wires twisted together, 3 turns per foot, for long runs of your power busses.  These would not be the Power Buss wires that track feeders attach to.  It would be the main power buss runs to get power to the actual power busses that run under the track that the track feeders really attach too.

Thanks,


 

--

Alexander Wood

Hartford-New Haven, CT

Modeling the modern era freelanced G&W Connecticut Northern in HO

Digikeijs DR5000 - JMRI - ProtoThrottle - TCS UWT-100 - TCS UWT-50p - Digitrax Simplex



--

Alexander Wood

Hartford-New Haven, CT

Modeling the modern era freelanced G&W Connecticut Northern in HO

Digikeijs DR5000 - JMRI - ProtoThrottle - TCS UWT-100 - TCS UWT-50p - Digitrax Simplex


Don Vollrath
 

The interference we speak of is not between the two wires of the DCC bus wiring, but essentially what is radiated to or received from other wires in the typical rats nest of wires under the layout. Twisting the DCC pair causes the radiation pattern to alternate in polarity, which tends to nullify the pickup coupled to other wiring.

Yes, the parallel rails of the track are not twisted. And they do tend to radiate EMI noise. But they don’t lay right next to another rail like a group of wires do in a bundle of under the table wiring.

DonV


Nat Hill IV
 

Now THAT makes sense.  Thanks so much.  I think I'm beginning to  understand why we "twist."  Was going to do it no matter what, just couldn't figure out why the tracks weren't a big problem.  But you explained it very well.

THANKS!

Nat

On 4/14/2022 9:40 AM, Don Vollrath wrote:
The interference we speak of is not between the two wires of the DCC bus wiring, but essentially what is radiated to or received from other wires in the typical rats nest of wires under the layout. Twisting the DCC pair causes the radiation pattern to alternate in polarity, which tends to nullify the pickup coupled to other wiring. 

Yes, the parallel rails of the track are not twisted. And they do tend to radiate EMI noise. But they don’t lay right next to another rail like a group of wires do in a bundle of under the table wiring.

DonV 




--
May the Good Lord take a likin' to ya' - Lester "Roadhog" Moran


 

Track as you note is not twisted. Track however is also not close to other wires that might create interference.

So what are the major sources of electrical interference on a model railroad.

twin coil switch machines.
Relays without some form of snubber.
Cell phones
Radio Communication.
Fluorescent lights
Static discharge

It does not hurt to twist wires but I don’t think it is necessary unless some of the above or their supply wires are within a foot of your DCC bus. Having your bus wires very close too each other does increase the capacitive load on you DCC drivers. At DCC frequencies this is low and your locomotive decoders provide a far higher capacitive load. Twisted wires also reduce the inductance that your DCC drives sees. This will reduce the need for snubbers at the end of long DCC buses. The need put snubber on will also depend on how your decoder deals with the spikes. A well designed decode will have no trouble with spikes but it does add a few pennies to the cost.

The only other thing is that twisted wires will reduce the amount of noise your DCC bus imparts to other sensitive circuits such a signaling and detection. PC serial buses are also somewhat sensitive although the sensitivity depends on how poorly it was implemented. A well designed PC serial bus will have no problems regardless.

I am not using twisted pairs and the run is somewhat more than 30’. I have a life time of professional experience with this sort of thing and so I will have no problem sorting it out if I do develop problems.

Ken Harstine
413-250-8298