Date   
Re: Polarity problems

Flash Gordon
 

You have reverse loops in both layouts. Has nothing to do the the crossings. They are internally isolated.

Looks like you are using RTS 8. RTS 8 will show you where you have a reverse short.

If you post the actual RTS 8 file, I can mess with it.

Ed S

Re: Polarity problems

Chuck Stiles
 

Bob
You have created a couple of reversing loops in this layout.
If you have indicated in Green where your isolators are, your correct there is not enough.
Try starting color coding your rails on paper Blue and Red or Black & Red (identify Rail A & B clearly)
If you are power routing color your turnout frogs Green along with your Isolators
Then you will be able to visualize the polarity better and show which sections you want to isolate treat as a reversing section.
There are several ways to handle these, and suggestions on Allen s website! (good reading)
Chuck Stiles
NJ


---In WiringForDCC@..., <bob_pombrio@...> wrote:

Folks I need some help with a few polarity issues I have going on with regards to crossings.  I have put a couple of pictures of the layout up in the files section 

https://groups.yahoo.com/neo/groups/WiringForDCC/files/Bob%20P%27s%20layout/
Files->Bob P's layout

Both levels of my layout have crossings the lower has 2 and I can not seem to keep the polarity correct.  The lower level is built and the track is laid, the upper level as been started.  I didn't see the shorting problems until I was trying to configure my Switch-8's and Switch-It.  I know that I have put put some isolaters in but I'm not sure where.

Any help you could give me will be a big help!

Thanks,
Bob P.

Re: Wiring Setup

Steve Haas
 

<<I have a question about the length limit of 25 feet. The NEC directions say that you should use at least 14AWG wire and limit the wire length to 25 feet. Does the main and each of the sub busses each have to be 25 feet or less?  Or is it the length of the main bus up to where the sub bus connects plus that sub bus length?  How does this 25 foot limit work? >>

 

Quoting directly from the NCE Power Pro System Reference Manual:

 

“For the hobbyist wiring up a new layout our suggested wire sizes based on voltage drop are:

 

Runs to twenty-five feet         #16

Runs to fifty feet                    #14

Runs beyond fifty feet           #12

 

For best results on long runs (over twenty feet), twist the bus wires about three turns per foot.”

 

 

Note that the “limit” for runs of AWG #14 is fifty feet, not the 25 you mention.  This alone might resolve your questions.

 

When we’re talking about buses we need to keep two things in mind:

 

1)      Power loss (voltage) over distance, and

2)      Distortion of the DCC signal due to inductance.

 

Voltage drop is minimized by increasing wire size; signal distortion is minimized by twisting the wires (keeping the wires in close proximity allows the magnetic fields generated by each of the wires to cancel out the magnetic field created by its partner).

 

The length of wire limits are not “hard” limits – a #16 bus will not fail at 26 feet.   The limits are “suggested” because at some distance beyond that recommendation, voltage loss will drop below that needed to provide voltage, current and signal to the track.  Wiring should be designed with the suggestions in mind; however, there is _some_ room for exceeding those limits.

 

I’ll defer to those who know the math of voltage loss over distance to provide the scientific answer to the total voltage loss of a length of size “A” followed by a length of size “B”,  but anecdotally there seems to be some room for deviation.

 

Every layout is very unique, so it is hard to know at what length of bus problems will start impacting operation.  Because of this, when wiring new layouts (or gutting and completely rewiring an existing layout to stay as close to the recommendations as possible – its not a binary question of “less than X you are fine, more than X you will definitely have problems” – it is a very analog situation – at some point problems (obvious or not so obvious) will start showing up.  The closer you hold to the recommended good practices, the lesser you can expect to have problems down the road.

 

 

All of this is a long way of saying:

 

1)      Know _why_ certain recommendations are made

2)      Follow these recommendations as much as possible, but don’t anguish over minor deviations resulting in major economic savings.

 

Best regards,

 

 

Steve Haas

Snoqualmie, WA

polarity issues

bob_pombrio@...
 

Folks I need some help with a few polarity issues I have going on with regards to crossings.  I have put a couple of pictures of the layout up in the files section 

https://groups.yahoo.com/neo/groups/WiringForDCC/files/Bob%20P%27s%20layout/
Files->Bob P's layout

Both levels of my layout have crossings the lower has 2 and I can not seem to keep the polarity correct.  The lower level is built and the track is laid, the upper level as been started.  I didn't see the shorting problems until I was trying to configure my Switch-8's and Switch-It.  I know that I have put put some isolaters in but I'm not sure where.

Any help you could give me will be a big help!

Thanks,
Bob P.

Polarity problems

bob_pombrio@...
 

Folks I need some help with a few polarity issues I have going on with regards to crossings.  I have put a couple of pictures of the layout up in the files section 

https://groups.yahoo.com/neo/groups/WiringForDCC/files/Bob%20P%27s%20layout/
Files->Bob P's layout

Both levels of my layout have crossings the lower has 2 and I can not seem to keep the polarity correct.  The lower level is built and the track is laid, the upper level as been started.  I didn't see the shorting problems until I was trying to configure my Switch-8's and Switch-It.  I know that I have put put some isolaters in but I'm not sure where.

Any help you could give me will be a big help!

Thanks,
Bob P.

Re: Emergency stop button -- IMHO

george hohon3
 

I'm always amazed by the trait held by a great majority of model railroaders that causes them to by pass the "keep it simple stupid" principle and they go off and try to complicate things.  From track road sub-base, to switch machines, to scenery, and everything in between, there is someone out there that has a better, faster, less expensive way to do something.  It never fails.

As for turning the power off to the layout room, the discussion has gotten so complicated, one might think we're talking about launching some sort of man eating robotic device that needs to be rendered useless if we're called for dinner.  I like to eat just as much as the next guy, but I hardly call it an "emergency" and if you're in a position that you must consider it so . . . you might want to evaluate your relationship with the dinner maker.

KISS - I have three (3) lighted 15 amp switches on the exterior wall of the layout room, right next to the door.  More than enough power to run a decent sized HO layout.  If the switch lights are 'ON' . . . the room has power.  If the switch lights are 'OFF' . . . the room has no power.

George
Keeping it Simple 


From: mrb37211@...
To: WiringForDCC@...
Date: Sat, 15 Feb 2014 21:10:06 -0600
Subject: Re: [WiringForDCC] Emergency stop button -- IMHO

 

Consider this switch on the wall plug side of the layout. Note that the hot and neutral wires are both connected to the switch itself. 

How it works: The "ON" button is a momentary contact, normally open switch which activates a built in solid state relay when pressed. That relay connects the wall plug to your layout. To shut everything down, press "STOP"  which disconnects a momentary contact normally closed switch to deactivate the built in relay. 

These switches are sold primarily into the power tool market - table saws etc. 

Woodstock D4160 110-Volt Paddle Switch by Woodstock http://www.amazon.com/dp/B005W17HYY/ref=cm_sw_r_udp_awd_1Ncatb0CV9N0N

Charles

On Feb 15, 2014, at 11:32 AM, Ed S <eschwerkolt@...> wrote:


Hi Greg,

i want to turn everything on the layout off with one switch, because of all you mentioned, including dinner.

Let’s go back a few weeks.

Someone posted that a friend had a fire in his basement. The firemen said it was caused by an electrical short in a train layout, the wire along the bottom of the table had heated up (main buss maybe) and started the fire.

The poster wanted to know if this was possible.... after a lot of discussion....  the owner of the layout admitted he had forgot to turn the layout off.

Most likely the main bus was not heavy enough wire to carry enough current to trip the booster. A minor short occurred, probably a derailment.  The owner went to dinner, did not turn off the layout and ……..  smoked the layout.

Since I am older and do dumb things, I thought it was best for me to be able to turn everything off in an emergency or when I leave the room.

So I came up with this Emergency Shut Off Button.  It will work and do what I want it to do.... turn everything off. For quite awhile many have joined in the middle of the conversation and added many great ideas and I thank them all.

Can we STOP now pleaseeeeeeeeee?

Carl, we had those emergency stop button in the school shops where I taught. Probably where I got the bright idea.

Thanks

Ed S



At 11:40 AM 2/15/2014, you wrote:
 

Hi Gang:

In tool and die trade school they had Master Emergency Buttons several places around the shop. Any one could shut all the shop machines down, only the instructors could turn it back on with a key.

With Digitrax you can unplug the throttle and walk to the next plug in and the locomotive will keep going.

Missing dinner is a major crisis. What is it you wish to avoid? A runaway locomotive, a track short burning up a passenger car, fire in the boosters?

Carl.

Re: Wiring Setup

Flash Gordon
 

Johnny,

Take a look at this site on DCC wiring. About 1/3 of the way down look for heading "considerations for layout with long bus wires". It will explain why and what can be done to solve the problem.

Now some will answer that is it not important even though a bit a research has been done and published and your manufacturer recommends it. So read up and decide what is best for you. I am going with the manufacturer.

That site has many pages of useful info.


Ed S



07:50 PM 2/15/2014, you wrote:



I have a question about the length limit of 25 feet. The NEC directions say that you should use at least 14AWG wire and limit the wire length to 25 feet. Does the main and each of the sub busses each have to be 25 feet or less? Or is it the length of the main bus up to where the sub bus connects plus that sub bus length? How does this 25 foot limit work? Thanks...Johnny

Re: new member w/questions

Mark Gurries
 


On Feb 15, 2014, at 6:49 AM, <harfrompa2@...> <harfrompa2@...> wrote:

My question is this-- will running the bus wire thru metal brackets cause a problem of any kind?

Electrically no.  The brackets will not cause any problem.  This is independent of how you run you wiring between the brackets.

As was commented before, wiring modifications may become a problem._,_._,___

Best Regards,

Mark Gurries
Electrical Engineer
DCC Website & NMRA DCC Clinics: www.markgurries.com



More questions

harfrompa2@...
 

Hi Everybody,
I have some more questions.
1-- I have read that the main power bus should not be over 30' long and that distance is from the booster. I can, however, go 30' in two directions for a total of 60'. On a multi deck layout I can go 30' out on three levels, one over the other two. And again in two different directions.  Of course this includes actual lenght of the wire, not layout lenght. So if the booster is below the lower level, I could have 6 pair of main bus's- one pair to the right and another to the left of each level. 
2-- The lenght of the sub bus cant be used to make a main bus longer.IE-- making a 10' sub bus off the end of a 30' main bus (total of 40')
3-- Should feeder wires be kept as seperated as possible? No wires actually touching in places where they cross each other?
4- I am assuming that a power booster is different from a base unit? The base unit receive the controls from the throttle (wireless or not). A power booster just adds power to make up for the power lost from wire lenght, number of locomotives etc.?
My layout is a narrow gauge line so there wont be any multiple units running.

I think I may be getting a bit of this down, I just want to be sure I am doing this right from the start. 

Harry 

Re: Emergency stop button

Glenn
 

They would be great with exceptions.

 

For low voltage use, aka, track power, you can solder leads to the terminals. For AC use you will need a junction box and cover and you will also need ¼” female quick-disconnect crimp-type wire terminals.

 

The wiring diagram shows two circuits in the switch, like a DPST switch. If that is the case you could shut of power to two separate power systems.

 

These are machine on-off switches. They have an added feature as the yellow “Safety Key” portion is removable. Without it in place the switch will not turn on. This could be a plus since without it in place only authorized people could turn on power.

 

My power equipment has a similar set up. I glued the yellow tabs in place with caulk so I would not lose them. I can pry them out with a screw driver if needed.

 

Glenn

 

 

 


On Behalf Of Lynn Finch

Subject: [WiringForDCC] Re: Emergency stop button

 

Try www.grizzly.com   search Part #G8988,  10 amps  @ $3.95.  They have other switches too.

 

Lynn Finch

 

Re: Emergency stop button -- What Do You Want It To Do

Glenn
 

What the Emergency Stop button does is up to the individual modeler.

 

IMHO I would treat the Emergency Stop button as a panic switch to avoid a collision, running off the end of track, derailment etc.

 

Answering the Dinner Bell would be more of a casual shut the power off switch and chow down.

 

The Emergency Stop button does not necessarily need to shut power off to the entire layout. I would think shutting the track power is the most important part, either by shutting off the AC power to the system or by disconnecting the track wires from the system thus disrupting track power.

 

Other power systems, layout lighting, building lights, signaling could be shut off at a control center. They would not be as urgent as avoiding a collision etc.

 

Glenn

Re: Emergency stop button -- IMHO

Charles Brumbelow
 

Consider this switch on the wall plug side of the layout. Note that the hot and neutral wires are both connected to the switch itself. 

How it works: The "ON" button is a momentary contact, normally open switch which activates a built in solid state relay when pressed. That relay connects the wall plug to your layout. To shut everything down, press "STOP"  which disconnects a momentary contact normally closed switch to deactivate the built in relay. 

These switches are sold primarily into the power tool market - table saws etc. 

Woodstock D4160 110-Volt Paddle Switch by Woodstock http://www.amazon.com/dp/B005W17HYY/ref=cm_sw_r_udp_awd_1Ncatb0CV9N0N

Charles

On Feb 15, 2014, at 11:32 AM, Ed S <eschwerkolt@...> wrote:


Hi Greg,

i want to turn everything on the layout off with one switch, because of all you mentioned, including dinner.

Let’s go back a few weeks.

Someone posted that a friend had a fire in his basement. The firemen said it was caused by an electrical short in a train layout, the wire along the bottom of the table had heated up (main buss maybe) and started the fire.

The poster wanted to know if this was possible.... after a lot of discussion....  the owner of the layout admitted he had forgot to turn the layout off.

Most likely the main bus was not heavy enough wire to carry enough current to trip the booster. A minor short occurred, probably a derailment.  The owner went to dinner, did not turn off the layout and ……..  smoked the layout.

Since I am older and do dumb things, I thought it was best for me to be able to turn everything off in an emergency or when I leave the room.

So I came up with this Emergency Shut Off Button.  It will work and do what I want it to do.... turn everything off. For quite awhile many have joined in the middle of the conversation and added many great ideas and I thank them all.

Can we STOP now pleaseeeeeeeeee?

Carl, we had those emergency stop button in the school shops where I taught. Probably where I got the bright idea.

Thanks

Ed S



At 11:40 AM 2/15/2014, you wrote:
 

Hi Gang:

In tool and die trade school they had Master Emergency Buttons several places around the shop. Any one could shut all the shop machines down, only the instructors could turn it back on with a key.

With Digitrax you can unplug the throttle and walk to the next plug in and the locomotive will keep going.

Missing dinner is a major crisis. What is it you wish to avoid? A runaway locomotive, a track short burning up a passenger car, fire in the boosters?

Carl.

Re: Wiring Setup

John
 

I have a question about the length limit of 25 feet. The NEC directions say that you should use at least 14AWG wire and limit the wire length to 25 feet. Does the main and each of the sub busses each have to be 25 feet or less?  Or is it the length of the main bus up to where the sub bus connects plus that sub bus length?  How does this 25 foot limit work?  Thanks...Johnny  

Re: new member w/questions

Skip Barber
 

Seems to me that for every person/source that says "twist" there is one that says you don't have to.  At our large club layout, I did not twist, I just kept the bus wires about 1-2" apart. We have had no problems, but I can't say it wouldn't  be better if I twisted.  As the saying goes, "your mileage vary"  or something like that. 

He only thing I do know, is the shorter the feeders are from the track to the bus, the better.  Someone may even have reason to disagree with that and I will respect their opinion.

Skip Barber


On Feb 15, 2014, at 19:01, William Teeters <cozyflyr9398@...> wrote:

I have 460' of main and a helix. Not one inch is twisted. RR runs perfect. Can be seen on rockrail.org. Featured as Chicago Peoria and Western RR Run with Digitrax, JMRI Decoder Pro, Loconet checker, Ptb100 for setting up those pesky sound engines ect. Trying to twist wire, especially 14G stranded is not an easy job. Do your self a favor and just run straight wire. Bill Teeters



From: Ed S <eschwerkolt@...>
To: WiringForDCC@...
Sent: Saturday, February 15, 2014 3:53 PM
Subject: Re: [WiringForDCC] RE: new member w/questions

 
Harry,

Bus wires are to be twisted  3 turns per foot as I recall. #14 1irw minumum.....    Just cut a bigger groove.

Most folks will hang this wire from hooks. Easier to fix or change.

You untwist the bus at the point you add feeders, which could also be twisted. 

Ed S

At 02:39 PM 2/15/2014, you wrote:
 

Hi Everybody,

I posted a question earlier, regarding running power bus and metal shelf brackets. To clarify- I would like to cut a groove in the plywood to run the wire over the brackets and use a piece of rubber hose to prevent any chaffing of the wire's insulation against the top of the bracket. I just think it will be alot easire to cut the groove then drill all of those holes. The 15 brackets I mentioned are only on one section of that level of a three level layout and each bracket is a "U" shape so each hole has to be drilled thru both sides. Thats alot of drilling!

I now have more questions--- My plan is/was to run these grooves directly under the main line, but a few inches apart. If I do that I could drill down for a feeder wire and hit the bus wire. I can take each section of plywood (all 8' or shorter) and turn them over and not work so much from underneath. Each section of plywood will be a sub-bus with a terminal strip and shut off switch (block). It is not meant to be portable. My "plan" is this- lay the track and turnouts on a section, drill the hole for the feeder wires, turn the section over and solder the feeders on to the sub-bus, put a short piece of hose on the bus as needed at each bracket, pass the feeders thru the plywood to the top of the layout, use wire clips between each bracket and tape the wire temporaly in place so it does not get pinched between the plywood and the brackets, wire up the Blue Point turnout controls, turn the section over and solder on the feeders. It seems like everything on a multi level layout is done in reverse!!

And yet, another question-- how far apart should feeders be kept? Not each section of rail but under thae layout?  If I run a bus under the main line and have a passing siding on both sides of the main the feeder wires will have to cross. These wires will be run between the brackets and can be attached directly to the bottom of the plywood, not in a groove cut into the plywood.

Thanks again

Harry


Re: new member w/questions

William Teeters <cozyflyr9398@...>
 

I have 460' of main and a helix. Not one inch is twisted. RR runs perfect. Can be seen on rockrail.org. Featured as Chicago Peoria and Western RR Run with Digitrax, JMRI Decoder Pro, Loconet checker, Ptb100 for setting up those pesky sound engines ect. Trying to twist wire, especially 14G stranded is not an easy job. Do your self a favor and just run straight wire. Bill Teeters



From: Ed S
To: WiringForDCC@...
Sent: Saturday, February 15, 2014 3:53 PM
Subject: Re: [WiringForDCC] RE: new member w/questions

 
Harry,

Bus wires are to be twisted  3 turns per foot as I recall. #14 1irw minumum.....    Just cut a bigger groove.

Most folks will hang this wire from hooks. Easier to fix or change.

You untwist the bus at the point you add feeders, which could also be twisted. 

Ed S

At 02:39 PM 2/15/2014, you wrote:
 

Hi Everybody,

I posted a question earlier, regarding running power bus and metal shelf brackets. To clarify- I would like to cut a groove in the plywood to run the wire over the brackets and use a piece of rubber hose to prevent any chaffing of the wire's insulation against the top of the bracket. I just think it will be alot easire to cut the groove then drill all of those holes. The 15 brackets I mentioned are only on one section of that level of a three level layout and each bracket is a "U" shape so each hole has to be drilled thru both sides. Thats alot of drilling!

I now have more questions--- My plan is/was to run these grooves directly under the main line, but a few inches apart. If I do that I could drill down for a feeder wire and hit the bus wire. I can take each section of plywood (all 8' or shorter) and turn them over and not work so much from underneath. Each section of plywood will be a sub-bus with a terminal strip and shut off switch (block). It is not meant to be portable. My "plan" is this- lay the track and turnouts on a section, drill the hole for the feeder wires, turn the section over and solder the feeders on to the sub-bus, put a short piece of hose on the bus as needed at each bracket, pass the feeders thru the plywood to the top of the layout, use wire clips between each bracket and tape the wire temporaly in place so it does not get pinched between the plywood and the brackets, wire up the Blue Point turnout controls, turn the section over and solder on the feeders. It seems like everything on a multi level layout is done in reverse!!

And yet, another question-- how far apart should feeders be kept? Not each section of rail but under thae layout?  If I run a bus under the main line and have a passing siding on both sides of the main the feeder wires will have to cross. These wires will be run between the brackets and can be attached directly to the bottom of the plywood, not in a groove cut into the plywood.

Thanks again

Harry


Re: new member w/questions

Flash Gordon
 

Harry,

Bus wires are to be twisted  3 turns per foot as I recall. #14 1irw minumum.....    Just cut a bigger groove.

Most folks will hang this wire from hooks. Easier to fix or change.

You untwist the bus at the point you add feeders, which could also be twisted. 

Ed S


At 02:39 PM 2/15/2014, you wrote:
 

Hi Everybody,

I posted a question earlier, regarding running power bus and metal shelf brackets. To clarify- I would like to cut a groove in the plywood to run the wire over the brackets and use a piece of rubber hose to prevent any chaffing of the wire's insulation against the top of the bracket. I just think it will be alot easire to cut the groove then drill all of those holes. The 15 brackets I mentioned are only on one section of that level of a three level layout and each bracket is a "U" shape so each hole has to be drilled thru both sides. Thats alot of drilling!

I now have more questions--- My plan is/was to run these grooves directly under the main line, but a few inches apart. If I do that I could drill down for a feeder wire and hit the bus wire. I can take each section of plywood (all 8' or shorter) and turn them over and not work so much from underneath. Each section of plywood will be a sub-bus with a terminal strip and shut off switch (block). It is not meant to be portable. My "plan" is this- lay the track and turnouts on a section, drill the hole for the feeder wires, turn the section over and solder the feeders on to the sub-bus, put a short piece of hose on the bus as needed at each bracket, pass the feeders thru the plywood to the top of the layout, use wire clips between each bracket and tape the wire temporaly in place so it does not get pinched between the plywood and the brackets, wire up the Blue Point turnout controls, turn the section over and solder on the feeders. It seems like everything on a multi level layout is done in reverse!!

And yet, another question-- how far apart should feeders be kept? Not each section of rail but under thae layout?  If I run a bus under the main line and have a passing siding on both sides of the main the feeder wires will have to cross. These wires will be run between the brackets and can be attached directly to the bottom of the plywood, not in a groove cut into the plywood.

Thanks again

Harry

Re: new member w/questions

Vollrath, Don <dvollrath@...>
 

Harry,

You may later regret threading your wiring through holes or notches in any layout supporting materials, as it becomes a pain to modify. Pushing wires between the metal bracket and a notch in the overhead wood it is holding up does just that. You are far better off using an open S-hook or something similar and passing the wires under the brackets, or perhaps locate all the wires to between the outer end of the bracket and the fascia of the layout shelf. Add a small 2-3 inch fascia edge to the layout to hide not only the wiring but perhaps also the lighting means for the lower layers.

DonV  

 

From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of harfrompa2@...
Sent: Saturday, February 15, 2014 8:49 AM
To: WiringForDCC@...
Subject: [WiringForDCC] new member w/questions

 



Hi Everybody,

 

I have been a model railroader for a long time now and am currently building a new layout and I want to use DCC. I have a lot of questions. What I do know about DCC I have read in magazine articles or on-line groups. The biggest question I have right now is -- The layout I am building now is multi-level (three in all) and consist of 3/4" plywood supported by metal shelf brackets. Obviously I need to keep the wiring, etc from one deck so you dont see it on the lower level. I understand I shouldnt have a bus wire longer then 30'. I could run the bus wire under the plywood, and at each bracket drop it down, under and across. This would use up 5-6" of wire for each bracket. A 15' long section of the bench work has 11 brackets so I have used up over 5' of bus run. The best idea I have is to cut a groove in the plywood to allow the wire to run over the bracket and not lose any bus lenght. I did think about drilling hole, grommets, etc-- cutting a groove is much easier!. I would run the wire thru a short piece of rubber hose to prevent any contact between the bracket and the wire as well as wire supports in between each bracket. My question is this-- will running the bus wire thru metal brackets cause a problem of any kind? The brackets on the lower level extend out to the end of the plywood, the upper two level's brackets will be shorter to allow the lighing to be attached to the underside of the plywood. Thanks for any info and Im sure I have plenty of other questions.

 

Harry




Re: new member w/questions

harfrompa2@...
 

Hi Everybody, 

I posted a question earlier, regarding running power bus and metal shelf brackets. To clarify- I would like to cut a groove in the plywood to run the wire over the brackets and use a piece of rubber hose to prevent any chaffing of the wire's insulation against the top of the bracket. I just think it will be alot easire to cut the groove then drill all of those holes. The 15 brackets I mentioned are only on one section of that level of a three level layout and each bracket is a "U" shape so each hole has to be drilled thru both sides. Thats alot of drilling! 

I now have more questions--- My plan is/was to run these grooves directly under the main line, but a few inches apart. If I do that I could drill down for a feeder wire and hit the bus wire. I can take each section of plywood (all 8' or shorter) and turn them over and not work so much from underneath. Each section of plywood will be a sub-bus with a terminal strip and shut off switch (block). It is not meant to be portable. My "plan" is this- lay the track and turnouts on a section, drill the hole for the feeder wires, turn the section over and solder the feeders on to the sub-bus, put a short piece of hose on the bus as needed at each bracket, pass the feeders thru the plywood to the top of the layout, use wire clips between each bracket and tape the wire temporaly in place so it does not get pinched between the plywood and the brackets, wire up the Blue Point turnout controls, turn the section over and solder on the feeders. It seems like everything on a multi level layout is done in reverse!!

And yet, another question-- how far apart should feeders be kept? Not each section of rail but under thae layout?  If I run a bus under the main line and have a passing siding on both sides of the main the feeder wires will have to cross. These wires will be run between the brackets and can be attached directly to the bottom of the plywood, not in a groove cut into the plywood. 

Thanks again

Harry 

Re: new member w/questions

Carl
 

Hello Harry:

If you run your wires through the metal brackets, be sure you use Insulated wire. I know of many bus wires that are bare! Also as you work think of future maintenance. Wire joints under tables or scenery can be hard to find later.

If you have several "blocks" be sure to put an On/Off switch on each for trouble shooting. I used industrial circuit breakers on my layout. They do trip sometimes!

Tell us more of your layout plans.

Thanks, Carl.

Re: new member w/questions

David Heine <davesn3@...>
 

Hi Harry,

 

You can cut a groove in the plywood with a router or a dado blade in a table saw.  Actually, the kerf from a single blade may be enough for the wires.

 

You can drill a hole in your bracket, which I assume are made of steel.  You shouldn’t have any problem with running wires through them, but make sure you run both bus wires through the same hole.  Otherwise you will make a little induction heater.  I remember seeing one Sn3 layout with welded steel framework and he didn’t seem to have any problems.  I have also seen references to people using metal strut like Unistrut to build layout framework.  I use aluminum shapes for framing on my lift-ups.   Buildings with steel studs have wires running through them, which seems to be most commercial buildings, at least around here.

 

Will there be a fascia on the front hiding the brackets, lighting, etc.?  

 

Dave Heine

Easton, PA

 

 

From: WiringForDCC@... [mailto:WiringForDCC@...] On Behalf Of harfrompa2@...
Sent: Saturday, February 15, 2014 9:49 AM
To: WiringForDCC@...
Subject: [WiringForDCC] new member w/questions

 



Hi Everybody,

 

I have been a model railroader for a long time now and am currently building a new layout and I want to use DCC. I have a lot of questions. What I do know about DCC I have read in magazine articles or on-line groups. The biggest question I have right now is -- The layout I am building now is multi-level (three in all) and consist of 3/4" plywood supported by metal shelf brackets. Obviously I need to keep the wiring, etc from one deck so you dont see it on the lower level. I understand I shouldnt have a bus wire longer then 30'. I could run the bus wire under the plywood, and at each bracket drop it down, under and across. This would use up 5-6" of wire for each bracket. A 15' long section of the bench work has 11 brackets so I have used up over 5' of bus run. The best idea I have is to cut a groove in the plywood to allow the wire to run over the bracket and not lose any bus lenght. I did think about drilling hole, grommets, etc-- cutting a groove is much easier!. I would run the wire thru a short piece of rubber hose to prevent any contact between the bracket and the wire as well as wire supports in between each bracket. My question is this-- will running the bus wire thru metal brackets cause a problem of any kind? The brackets on the lower level extend out to the end of the plywood, the upper two level's brackets will be shorter to allow the lighing to be attached to the underside of the plywood. Thanks for any info and Im sure I have plenty of other questions.

 

Harry