Out door cable

[craigrailinc]

I'am interested the best cable to carry current.
I have a returning loop about 150 feet long (50 meteres ish) and suffer from a voltage drop at the far end.
I use alarm cable at present and I'am pressuming that my voltage drop is the length of the run of track. I use a 12amp Aristo Elite power supply. This maybe that too much power is trying to get to get down too small a cable.
In the past I used 2.5mm main cable but the power didn't get through. I was at that point using a small 2amp power supply. this maybe why the heavy cable wouldn't carry a small current that's why I changed to alarm cable.
I still have the 2.5mm cable.
As I will be adding a branch line down the other side of the garden about 150 feet back to the shed. I have other intermediate feeds in but now i've tested it with a volt meter rather than "it seems to be slower" it drops 20% about 90 feet away and 40% at the 150 feet any suggestoins? I have tightened all the fish plates prior to putting a volt meter on it.
Can anyone suggest a cable gauge that would be a good conductor for me?
Brian

 

[Gizzy]

Well code 332 track cross section should be more than 2.5 mm? Have you also cleaned the fishplates? I personally use a small half pea sized amount of Copperslip in my rail joints, although others do without and some use the LGB paste.

You could try 4 mm cable (not sure of the size of your alarm cable), but I would measure and confirm the voltage drop on the end of your current cable first? Cable is not cheap!

If it is a cable length problem, then consider trying LGB 1015T reverse loop track set. This will change the polarity of your loop without the need of a cable and switch. You could even make one yourself using a bridge rectifier or 4 diodes if you are electrically minded and handy with a soldering iron....

 

[Neil Robinson]

I can't think of any reason why the mains cable failed to carry the current, at 2.5mm2 it would have a greater cross sectional area and therefor a lower voltage drop per unit of current and length than most alternatives.
However I favour flexible cable for any installation where the cable isn't firmly fixed to some sort of structure as the single strand mains cable may fracture with movement.
Heavy duty speaker cable is one suitable alternative, the greater the cross sectional area the better. Personally I wouln't pay extra for the very high purity copper option as loss of sound quality isn't an issue with this application!

 

[craigrailinc]

HI Gizzy
thanks for coing back to me again.
The alarm cable is very thin.
To clarify the track goes up side, around the loop and back down on another track beside the first one.
The 2.5mm is the gauge of cable which is ring mains cable and not the cross section of track. sorry for the confusion.
I can measure the drop as one of the intermadiate feeds is at the far end where it drops 40%.

 

[Neil Robinson]

2.5mm2 cable typically has a resistance of around 7 ohms per kilometer.
So if you used 1Km of cable to run a feed to a piece of track 500m away (two wires each 500m long, one to each rail) you'd loose around 7Volts from end to end for every amp passing through it. Twice as much for twice the current, half as much for half the length.

 

[bahnman]

you must have a problem where your rails join, as the best conductor for the current is the rail itself,it does not matter how many feeds you put in unless the wire you use is thicker than the rail, it will not make any difference to the voltage drop,I would suggest that you bond all your rail joints, use min of 2.5mm wire, you will still get a voltage drop, the longer the track the more the voltage drop you will get, you will also get a voltage drop through the diodes in your return loop,
What I do is, (without getting tecnical) run a feed to the loop direct from the controller and then another feed to the main run of track with maybe 5-6 diodes in it,( this will take a bit of trial an error as to how many diodes you need to use) make sure you put these in pairs 1 one way round another the other way round, otherwise your train will only go in one direction as this reduces the voltage to the main run, and keeps the voltage in the loop to what ever you set the controller at, the train should run into and out of the loop at a constant speed "hope this is of some help"

 

[Gizzy]

HI Gizzy
thanks for coing back to me again.
The alarm cable is very thin.
To clarify the track goes up side, around the loop and back down on another track beside the first one.
The 2.5mm is the gauge of cable which is ring mains cable and not the cross section of track. sorry for the confusion.
I can measure the drop as one of the intermadiate feeds is at the far end where it drops 40%.

Hullo Brian,

I feel I may have confused you!

What I was trying to explain, rather badly, is that the cross section of the code 332 rail is higher than the 2.5 mm cable, so have you checked to see if there is any volt drop across the rails at the furthest point, just before where your track returns, with the cable disconnected?

You might not even need the cable feed if the track joints are sound.

The alarm cable certainly doesn't sound man enought for the job, and Neil's suggestion of speaker cable may be the best way to go if you have a volt drop across the 2.5 mm cable.

Though with around 18V at 12A for your power, a similar TE set up to mine, albeit a longer track run, I'm surprised that you are experiencing a volt drop on 2.5 mm mains cable....

 

[craigrailinc]

Hi Thank you for the replies.
What seams to be coming through is to bond the track together rather than run intermediate feeds.
Do the members think this is the way to go?
I am not going to get into the how to bond as ther is a thread on this. I am no expert.

 

[Gizzy]

Hi Thank you for the replies.
What seams to be coming through is to bond the track together rather than run intermediate feeds.
Do the members think this is the way to go?
I am not going to get into the how to bond as ther is a thread on this. I am no expert.

I concur, but you could try the copper slip method first and see if this solves your problems, before bonding....

 

[bahnman]

what you will need is a 120w iron min to get the rail hot enough to bond the wire to the rail, and to make sure that the rail is clean, some flux and some solder, best to do on a warm summers day wiihout any wind blowing as this will cool down the iron, and the job in hand

All my track outside has been bonded and has been down for 30yrs with no problems

 

[Neil Robinson]

Hi Thank you for the replies.
What seams to be coming through is to bond the track together rather than run intermediate feeds.
Do the members think this is the way to go?
I am not going to get into the how to bond as ther is a thread on this. I am no expert.

With LGB type heavy section track I certainly favour bonding or clamping track joints rather than multiple feeds, and I'm sure many members will agree. I'm equally sure many members will choose to differ based on their experiences.

What is indisputable is that voltage drop is linked to conductor cross sectional area. Also local relatively high voltage drops occur at poor quality joints.

LGB track, by my calculation, is around 15mm2, six times the area and therefore creating a much lower voltage drop than 2.5mm2 cable of the same length for the same current even allowing for the differences of conductivity between copper cable and brass track.

 

[korm kormsen]

What seams to be coming through is to bond the track together rather than run intermediate feeds. Do the members think this is the way to go?

a second (third, or more) feed may be usefull.
depends on your layout.
if the second feed is considerably shorter between the powerpack and the point it feeds at, than the original feed plus the rails to that same point, then i would put that additional feed.

if not, make better the connections between rail-sections.

 

[bahnman]

Best track for conducting is brass 1st = LGB
2nd = Piko
3rd = Tenmille
4th = aristcraft
5th = Peco
I would always recomend LGB ( if you can get hold of it ) and if it is all bonded outside there will be no problems, as the rail will conduct better than wire there should be no need for extra feeds as this will make no difference unless there is a fault in the track, the paste is ok inside but after a while outside it will stop working due to all the ellements of being outside, rain, snow, frost, wind, and sun ( when we get it ) then there is all the wildlife to contend with

 

[craigrailinc]

what you will need is a 120w iron min to get the rail hot enough to bond the wire to the rail, and to make sure that the rail is clean, some flux and some solder, best to do on a warm summers day wiihout any wind blowing as this will cool down the iron, and the job in hand

All my track outside has been bonded and has been down for 30yrs with no problems

Bonding is the way to go based on the feedback. I now understand thanks to replies that the track will conduct better than copper wire.Thank you all who took the time to reply.
Track has been ouside for 2 and half years I did use graphite paste when it was layed but elements have played there part.
Glad I didn't start the wiring job and asked as would have wasted a lot of time.
I can get a soldering iron, got some flux and solder but a bit short of a warm summers day has anybody got a spare one of them?

 

[minimans]

Funnily enough I don't solder my joints anymore! I just use a self tapping screw through the fishplate and foot of the rail. But if you do want to solder the best method I've found is with a small butane torch with the flame set to a pinpoint it gets the rail hot enough to solder properly in a short time, when the wire is soldered hit the area with a wet cloth to stop the ties melting job done! if you try doing 150ft with a small Iron you'll give up and model HO..................

Or use clamps which are brilliant but a bit expensive......................

CLAMPS

 

[bahnman]

I suggest useing an electric iron min 120w, not a gas torch as you will heat the rail to hot and melt the plasic sleepers if you use a gas torch, make sure that where you bond the wire to on the rail is clean and not to much flux, and it should be no problem, try not to do it all at once otherwise you will get bored with it, I have about 4000ft of track outside which is all bonded, it is well worth doing for trouble free running. best of luck

 

[minimans]

Y

I suggest useing an electric iron min 120w, not a gas torch as you will heat the rail to hot and melt the plasic sleepers if you use a gas torch, make sure that where you bond the wire to on the rail is clean and not to much flux, and it should be no problem, try not to do it all at once otherwise you will get bored with it, I have about 4000ft of track outside which is all bonded, it is well worth doing for trouble free running. best of luck

You must have been doing it wrong then! I don't recall ever melting the ties at all, Drill a hole in rail, flux, add wire, heat and dab solder on, apply wet rag...........................

 

[bahnman]

I should know better at my time in life, " do not anwser anymore posts " as I have been doing it all wrong, the guy that 1st posted this ( craigrailinc ) is a junior its not a good idea for him to use a gas torch in my opinion, safer to use a electric iron plus he has one to hand.:

http://www.youtube.com/user/brockenbahnman

http://bahnman.camstreams.com/

 

[craigrailinc]

Stop!
all suggestions are welcome and i'll decided whats best for me.
I really appreciate all the advice and offers of help every one has made a great contribution to helping get started and saving me time.
anyway my other half wouldn't me loose with a butane torch!! she knows me so well.

 

[daveyb]

just a thaught to this thred,,, theres a product now for plumbing where instead of soldering fittings you can glue them together a superglue for copper,,, i wonder if this will work on brass track,,,,

any thaughts,,,,,

davey b