Star or home run wiring?

Big Mike G,

  IMO if you are setting up a new layout, use the the star type wiring, if you already have a Buss type layout, add the DCS and see what happens.  You may not even have to alter your wiring except for setting up blocks and even then, you maybe able to cheat a little to accomplish what you want.  IMO engineering a new layout is quite different than adding to an existing one.

BALIDAS,

Soldering is not really the full answer as to blocks and track joints.  IMO the DCS signal is altered by the pin joins in each section of track no matter the length, soldering track together does not alter the DCS signal degradation, because the Track pins are still setting up a DCS signal resistance, in fact soldering might be like adding another single track pin to the signal flow, not helping it at all, we are talking signal here not power.   Remember DCS signals flow both ways thru out your layout. The object is to attain as close to a 10 signal strength thru out your layout as possible, assuring great DCS running operations. Do not confuse DCS signal with power on the tracks, two different engineering criteria.

IMO trouble shooting a layout when you use terminal blocks is a lot easier to accomplish most time, of course this also depends the size of the layout.

PCRR/Dave

Dave, I haven't even started yet, I just started building the building for the train room. It will be a little while before I even ge3t to wiring. I am just trying to understand for when the time comes. I figure if I start studding now I will have a grasp on it when the time comes! 

So I was thinking about a star wiring, just did know enough for around the room layout!

Mike G,

   Remember I have star wiring for my around the room, ceiling shelf layout.  It's just a matter of running the high quality 14 Gauge stranded wiring back to a terminal block location.  Remember also you use more wire with this engineering method than with Buss wiring.  It does work quite well however.  I am meeting Mark & Bob for breakfast tomorrow morning to get to know them better and to pick up some additional, MTH Terminal Blocks that I will need to continue building the DCS/Legacy layout, thru out our new Train Room.  Which is all in the planning stages right now, similar to yours.

PCRR/Dave

Pine Creek Railroad posted:

Mike G,

   Remember I have star wiring for my around the room, ceiling shelf layout.  It's just a matter of running the high quality 14 Gauge stranded wiring back to a terminal block location.  Remember also you use more wire with this engineering method than with Buss wiring.  It does work quite well however.  I am meeting Mark & Bob for breakfast tomorrow morning to get to know them better and to pick up some additional, MTH Terminal Blocks that I will need to continue building the DCS/Legacy layout, thru out our new Train Room.  Which is all in the planning stages right now, similar to yours.

PCRR/Dave

I will keep that all in mind. Maybe when the time comes I can send you a layout drawing and you can help me with the wiring?

Pine Creek Railroad posted:

BALIDAS,

Soldering is not really the full answer as to blocks and track joints.  IMO the DCS signal is altered by the pin joins in each section of track no matter the length, soldering track together does not alter the DCS signal degradation, because the Track pins are still setting up a DCS signal resistance, in fact soldering might be like adding another single track pin to the signal flow, not helping it at all, we are talking signal here not power.   Remember DCS signals flow both ways thru out your layout. The object is to attain as close to a 10 signal strength thru out your layout as possible, assuring great DCS running operations. Do not confuse DCS signal with power on the tracks, two different engineering criteria.

IMO trouble shooting a layout when you use terminal blocks is a lot easier to accomplish most time, of course this also depends the size of the layout.

PCRR/Dave

Understood. Thank you.

Can solid copper wire be used as a "buss bar" and then the drops from the tracks be stranded and soldered to the buss bar? Isn't it true that AC prefers solid wire and will travel farther and better through it then stranded? 

Dave Zucal posted:

Can solid copper wire be used as a "buss bar" and then the drops from the tracks be stranded and soldered to the buss bar? Isn't it true that AC prefers solid wire and will travel farther and better through it then stranded? 

Dave 

Actually just the opposite

Stranded conductors have a lower impedance than solid conductors due to an effect called hysteresis.  At higher frequency's current flows on the out side diameter of a conductor and not in the center of the conductor causing increased impedance.  By adding more strands current has more surface area to flow on.  Fortunately in the application of model trains our 60Hz system this is not a factor.  Nor are the currents and voltages and distances  we operate out trains at.  just use a minimum of 12 AWG or 10 AWG   (gauge) wire for your bus and you will be fine.  Hope this helps (:

Thank You Bill. When I went to Votech back in the 70's, we were taught that AC used the whole copper mass and DC ran the outer edge. Keeping up with electronics and new theories requires constant schooling to stay up to date. This forum really helps. Since I'm in the process of bench work and laying track, the thought of using solid for a buss bar, was because I thought it would be easier to strip where a drop would be attached. I always seem to nick or break a strand or two cutting into stranded buss wire. Can you provide any tricks to avoid wire damage when stripping along the length?

Bill_R posted:

Dave Zucal posted:

Can solid copper wire be used as a "buss bar" and then the drops from the tracks be stranded and soldered to the buss bar? Isn't it true that AC prefers solid wire and will travel farther and better through it then stranded? 

Dave 

Actually just the opposite

Stranded conductors have a lower impedance than solid conductors due to an effect called hysteresis.  At higher frequency's current flows on the out side diameter of a conductor and not in the center of the conductor causing increased impedance.  By adding more strands current has more surface area to flow on.  Fortunately in the application of model trains our 60Hz system this is not a factor.  Nor are the currents and voltages and distances  we operate out trains at.  just use a minimum of 12 AWG or 10 AWG   (gauge) wire for your bus and you will be fine.  Hope this helps (:

Dave 

The link below may do a better job of explaining skin effect than i can LOL

https://en.wikipedia.org/wiki/Skin_effect

Very interesting link BILL. Especially the use of pipe for a conductor. It pretty much is saying AC conducts through the mass but is forced to the edge by frequency. So, the more strands in a wire gauge, the more surface area it contains. It would be nice to see the surface measurement per inch calculated and stated when selecting  a specific gauge and brand. I know some do give a strand count.

Dave Zucal posted:

Thank You Bill. When I went to Votech back in the 70's, we were taught that AC used the whole copper mass and DC ran the outer edge. Keeping up with electronics and new theories requires constant schooling to stay up to date. This forum really helps. Since I'm in the process of bench work and laying track, the thought of using solid for a buss bar, was because I thought it would be easier to strip where a drop would be attached. I always seem to nick or break a strand or two cutting into stranded buss wire. Can you provide any tricks to avoid wire damage when stripping along the length?

Dave

If you use wire strippers that are  per gauged for specific  wire sizes you will never again nick of cut a wire when stripping off the insulation. 

https://www.amazon.com/Ideal-I...ideal+wire+strippers

Bill_R posted:

Dave Zucal posted:

Thank You Bill. When I went to Votech back in the 70's, we were taught that AC used the whole copper mass and DC ran the outer edge. Keeping up with electronics and new theories requires constant schooling to stay up to date. This forum really helps. Since I'm in the process of bench work and laying track, the thought of using solid for a buss bar, was because I thought it would be easier to strip where a drop would be attached. I always seem to nick or break a strand or two cutting into stranded buss wire. Can you provide any tricks to avoid wire damage when stripping along the length?

Dave

If you use wire strippers that are  per gauged for specific  wire sizes you will never again nick of cut a wire when stripping off the insulation. 

https://www.amazon.com/Ideal-I...ideal+wire+strippers

Ideal makes about 4 or 5 different strippers to cover all the wire sizes you would be working with.  I have two pait , one for larger conductors 14,12 and 10 AWG. and one pair for low voltage conductors 16 through 24 gauge.

Gentlemen,

   Anyone who builds a Train layout should definitely own a couple good pair of wire strippers.  Can't imagine building Train layouts without them.  

Remember also the multi Stranded wire we are talking about is mostly used for the DCS signal flow, not power flow.  If you like to use Single Strand wiring for your total Legacy Layout, no problem.  I use the stranded wire because I purchase enough for all my layout wiring needs, I am running both DCS and Legacy.

PCRR/Dave

Just this week I took my older (pre Rev L) TIU to the club's layout to try out DCS for the first time. The layout was built with no consideration for future DCS use (much to my chagrin) and uses a bus as it is quite large at 25' x 42' with 5 loops. I hooked up the TIU in passive mode (a first for me) with alligator clips to the rails of a siding expecting the worse. 

Much to my surprise, the locomotive started right up and seemed to have a solid connection as I ran it around one end of the outer loop - about 150' in each direction. We were doing some switch work adding Tortoise machines so part of the main line was closed down. Granted, I wasn't able to test all the track in the brief time I was there but I'm surprised and optimistic that we will have decent connection going forward.

Only two of us run MTH at present but one of the 'other' fellas has ordered a RK engine...

C Sam,

   Yes it is possible for a buss wired layout to run DCS,.  Yes people add DCS to older layout all the time in may cases it works very well.  However IMO when setting up a new DCS layout, go with the proven engineering and use the star wiring, and high quality 14 Gauge Stranded wire.

PCRR/Dave

Would it help to use tinned stranded vs bare copper?

BILL, thanks for the link. I too have just about every wire type stripper made. When stripping the end of a wire, you only have to get close to cutting all the way through and pull the coating off in order to avoid damage to the strands and if damage does occur, you can just try again. I was referring to stripping in the length, where you have make two cuts and a slice all the way through in order to expose a section of wire to solder to.  If you have a buss of 20 strands and goof at 10 drops, you could be left with only 10 undamaged strands at the end of the line.  Just thought maybe you knew of a fool proof way or tool specifically for this type of work.

Dave Zucal posted:

BILL, thanks for the link. I too have just about every wire type stripper made. When stripping the end of a wire, you only have to get close to cutting all the way through and pull the coating off in order to avoid damage to the strands and if damage does occur, you can just try again. I was referring to stripping in the length, where you have make two cuts and a slice all the way through in order to expose a section of wire to solder to.  If you have a buss of 20 strands and goof at 10 drops, you could be left with only 10 undamaged strands at the end of the line.  Just thought maybe you knew of a fool proof way or tool specifically for this type of work.

ok now i understand

use the correct wire stripper to make the circular cuts than use a razor knife to slice between the two cuts than peel off insulation.  i also have a buss type distribution  system. But i used  a connector that bites through the insulation so no stripping necessary.  attached is a link for the connector.  the main buss wire passes straight through the connector and the tap lays in the back of the connector.  you than close the cover and squeeze  it with pliers,  the blade bites through the insulation to make the permanent connection.

 https://www.amazon.com/dp/B004...gid=pla-353543313353

Well we successfully signaled 1,600' of brass 2 rail track using DC power with only 3 power drops on one Rev.L TIU channel and no blocks...just one big continuous loop and via passive mode. DCS was banging 10's & 9's with 15 locomotives mixed in with 600+ cars...That showed us just how powerful the Rev. L signal generators are.

Sometime those suitcase connectors will cut strands, too, and also sometimes not quite cut all the insulation. Not positive enough for me.