Anybody ever burn up a Track wire?

but at 10 volts thats 8 amps !!

The CW-80s I have all trip at right around 5 amps.  Try to feed an 8 amp load at 10 volts and they won't - don't have the capability for one, and the breaker will interupt first anyway.  Their 80 watt capability is basically 5 amps at 18 volts, they'll only do about 10/18ths of that at 10 volts before they start to suffer a drop in voltage because they can't provide the power at that voltage.  For example, I have a Lionel passenger set with four Pullmor motors and lighted (incandescent) cars that draws wants 7 amps at 11 volts (77 watts): a CW-80 will not feed it.  Connected to the track, its voltage falls to about 9 volts at 6 amps for a second or two before its green light blinks and it shuts down power feed.  I takes a Z4000 to run the run (10 amp limit).

 

There are several  things about with using "tiny wire" for feed wires that I think are objectionable, even if strictly speaking the wire (see table in post above) is within rating.  The two biggest are:

1) Heat.  Near the allowable ampacity, the wire gets very warm if that current is continuous - not dangerously hot and not enough to burn, but hot, and hot enough that if a sudden short occurs and isn't cleared immediately, or if there is other hot equipment nearby, things could get too hot.  Why take the chance?

2) Voltage drop.  I have feeds as long as 25 feet transformer to track (50 feet round trip).  If I use 18 gauge wire to carry its rated 6 amps, I get about 2 volts of drop from transformer to track.  I like to keep the potential drop on a feed below .5 volt.

So, even though I feed my track every ten to fifteen feet, I use #10 wire for feed runs less than 10 feet and #8 copper for my longest (a run just over 50 feet out and back).  It stays very cool even at 10 amps (the breaker limit of a Z4000) and I get nothing over .5 volt calculated serial drop in voltage anywhere on the layout. 

Umm interesting! I didn’t think of that. Good point.

 I’m going to have to get my amp meter out and actually measure it at different speed.

Lee is correct, you can't get 8 amps out of the CWS-80, at least I can't.

sorry, I wasn't taking into consideration the circuit breaker rating

I will add though, that last night I opened up my ZW to replace the rollers, and for what they are rated at the wiring inside them is pretty skimppy looking !!

Regarding the #14 wire. If you have a Lowe's near you, I believe they have it on a 25' spool. It comes in colors, red, black, blue, green, & yellow. They may also have it on a larger reel of 50' or 100', but you may have to ask the sales person for assistance.

Thanks Bill, I was over there last week looking for something and they had 14/2 listed in the prices, but it wasn’t available in any of the 3 stores I visited. I don’t know what kind of wire it was, but I assumed it was lamp cord.

 

 

I just wanted to also say that some of the burnouts mentioned here have reminded me of a time when I was kid. I hooked up my dad’s Lionel transformer to my slot car track and I have to say that those slot cars never went so fast. It was very amusing to see them go up in smoke as they hit the walls, but the fun was short lived when I realized that I didn’t have a slot car set anymore. The rails in the track melted the plastic.

Keep in mind it is not just the breaker rating.  A CW 80 and most power supplies will pretty much provide dependable power proportional to voltage.  In other words, at 9 volts (half of its max of 18) the CW-80 will provide only about 40-45 watts (just under its 5 amp breaker limit, times 9 volts).  That's just the way they work.  If you need 80 watts at 9 volts (9 amps) you need a Z4000 or something similar that can provide 180 watts at 180 volts.

Wow Lee, you sure got this stuff down, I’m impressed. I’m learning so much here thanks for the info.

Another  couple of points on this wiring issue.

 

From an enginerring point of reference, too thick wire is a waste of money.

 

From a NEC perscpective, since the track is technically a conductor, than the  feed wire guage should actually exceedor equal the cross sectional area of the track not taking into acount the difference in conductivity between the copper (hope no one is useing aluminum wire) and track. But that is not practical and the class 2 low voltage category exempts it. In the sign industry we reguarly run  18-22 gauge 800 VAC secondaries off high output florescent ballasts with no issues (miliamps of course. It is always the current that causes the issues)

 

And from a common sense perspective, Think of wires as  water pipes. Put a 1" feeder to your shower and connect that to a 1/2" main. It will never burst but you will trade off pressure.

 

Open up any power supply and measure the wire guage connected to the breaker.

Anything larger by one size is all the safety factor you would ever want. Anything more is a waste.

 

your limit is the potential at the source and your are not going to get anymore out of it.

FMH

I use 16 AWG two wire MTW cable for my mains and 18 guage 3 wire (RBW)

All outdoor exposure rated, stranded copper, rated for 1000V.

Best in the industry.Used primarily for secondies on LED circuits.

Luckily I can proccur what I need from the recycle bin (trash) at work. Scrap value does not warrent the storage and handling costs.

But I would not use anything larger even if I had  free access to it.

FMH

 

Johnny B.

The 14/2 wire here at my Local Lowe's is stranded copper and they have a huge selection. You may also try your Local Home Depot or Radio Shack. Good Luck wih your search.

Thanks Bill

I think "Ffffreddd" made a good point, large wire dose not always mean fire safe.

A person can run "750MCM" to his switch motors, with 10 amp breakers on it. But, if that switch becomes a heater because of a high resistive short what you made was a toaster.

I know I am way over the top here but my point is just becuase your circuit protection is adequate for the conductor used dose not mean the componets can't generate enough heat to start alot of trouble.

It comes down to this my friends,"we get what we inspect, not what we expect". So no matter how well thought out our electrical application there is no substitute for checking your wiring and accessories often and carry a big fire extingusher.

I love this, I'm going to use it for now on

The circuit protection should be sized for the load, not the wiring, that would solve a lot of issues like this.  If you have a separate switch power supply, fuse that for the maximum expected load, which is likely to be far less than the wire capacity.

Bad advice on the water pipe here, larger pipe is always better, especially if there are 90s in the line, it will have less pressure drop no matter how small the feed is, that is why we put a length of "1 1/4 copper in a yard sprinkler feed line that is fed by a "3/4, it slows the water speed to stop water hammer.  Go to www.genuinedealz.com/voltage-drop and enter your distance, amps and wire size. Example, 16gauge at 24 volts and 10 amps is only good for 14 feet with 5% voltage drop. The chart surprised me when I sized wire for my layout, I need a lot of 10 gauge. Make sure you size the wire for the biggest transformer you will ever have, thats why I always figure 25volts and 10 amps. Safety can only be provided by fuses and circuit breakers, the one place I think glass fuses are a pain, but the best for safety.

 

www.southwire.com also has a very nice technical site where you can plug in your figures and get wire size, do your research.

 

 

400e Do what you want. Run number 6 if you want. Putting a short section of pipe to reduce water hammer in a sprinkler system will still cause a pressure drop untill the system fills. You are still restricting at the nozzle increasing the final water velocity. Turn on a garden hose with and without a nozzle and tell me it's the same thing.

Hi Gunrunner, I agree with you that protecting you appliance (Train, radio, transformer) for both thermal protection and current overload is a good idea. Engines are expensive. But circuit protection is just that, designed to protect the wiring from overheating, not designed to protect your appliances. But as I said in the previous thread about the guy whose layout caught on fire, arcing through bad connections cause most of the problems, and wire is rated for its ability to carry current not wattage. 10 amps at 12 volts is the same as 10 amps at 120 volts as far as the wire is concerned. And as you said about protecting for the maximum load, I can not see any reason to have a power district with anywhere near 10 amps. FMH

Hi Lee, I am a big Nero Wolfe fan myself. If big wire makes you happy do it. Even Disney which has its own strict building code, require #10 wire where you would normally use # 12. One size bigger. But going 3 to 4 sizes bigger than what is needed seems to be silly to me and I do not feel that the benefit is there in my application. Nor do I feel that long runs of large wire is preferably to multiple feeders off the industry accepted standards for wiring. FMH

Sorry, I assume you would use a shower head or a nozzle, there is no such thing as too big of pipe or wire, only too small. In an operating system larger pipe will only slow the flow rate and lower the pressure drop, simple physics. I am not going to debate wire size with you, the voltage drop calculator with amp, volts, and distance entered is the right answer.

Hi Ace, Intend was not argue. I will admit my plumbing analogy was not the best, nor entirely correct. But if voltage drop is the issue, there are others ways to solve it. And yes there is no such thing as too big a wire. But how much current do you really want to or need to run on what essentially is knob and tube wiring. The exposed track. Put a sweaty forearm or maybe your kids across 10 amps and tell me it's a good idea. Maybe you need 10 gauge wiring. I do not think you need 30 amp capacity on a circuit that should trip well before that. FMH

Ok, I have an around the room layout wih 50 ft each way, how do I solve voltage drop with small wire, I am all ears. Current is controlled by the fuse, what size do I need for 2 powered a units a powered b and 12 lighted cars, 6 motors and 24 light bulbs.

Hi 400E, Did not mean to call you Ace. Visualize this. 18volts 10 amps Now using four 16 gauge feeders at maximum 25 ft each. Less than .46 voltage drop or your 3% good design Now factor in drops every 6-8 ft off the feeders. Then factor in the fact that your track itself is the equivalent of a #10 wire as another parallel conductor. Gets you down to about 1%. Great design. I know how to use the calculator ( try one that let's you use 18 volts and multiple conductors) And I do understand low voltage wiring. 12vdc and 24vdc LED signage is what I do. Got a 36,000 Lumen logo 18 stories up with 24 180 watt power supplies and nothing bigger than 16 gauge. No run longer than 50 ft. FMH

I follow everything said above and I agree with most of it, but I think what "Fffreddd" is trying to say is why use more copper then what is needed to do the job.

Like I said before, I have 18 gauge on short runs on my layout. I use the STAR pattern for power distribution to very short isolated blocks. In this way I keep the current draw down because there are never more then an engine and a couple of cars in any block at any time. 

John likes to fuse the circuit for current draw and that is very ok because I assume gunrunner is talking about if a #14 wire is only servicing a eight amp lode then fuse for ten and not fifteen amps. This fits with the numbers Lee quotes.

 

That said I have mostly 16 gauge wire on my layout with some 18 gauge and no matter where I take my voltage readings with my meter it all reads the same, with in .02 volt. This is true no matter if I am running a Big Boy with ten passengers cars behind it or a Lionel auto inspection car.

The reason for this, I believe is that the lode on any one block is never more then three or four amps because of the limited train on said block. Should there be a dead short the eight amp fast blow fuses will protect the conductors. I do use 14 gauge wire from the transformer to the star distribution terminal board, with the 8 amp fast blow fuse in said line. I have four total, lines one for each port on my TIU.

 

I think we are all talking the same science here, we are just addressing the issue in diffrent ways. In Lee's technique he is using a large pipe to provide the needed power to his layout, but I  am using many smaller point to point wires to service the same total lode. To be honest with you all, I'm not all that sure that Lee is using more copper then me because I got alot of runs to my track. 

 

I don't know what this means in a power discussion, but when I run my DCS engines I get a nine or 10 signal all over my layout, if the tracks are clean.

 

Again, no matter how thought out your wiring plan it can't hurt if we get in the habit of feeling our wires and accessories from time to time to make sure all is cool.

I had an uncoupling track that had the switch get stuck in the on position and that thing got very hot. It was a 4X8 floor layout that had Astro-truf on it. The carpet was starting to cook and the wire that came with the uncoupler track was as cool as a cucumber. I think that is 20 gauge wire, maybe 18, I'm not sure off of the top of my head. But, I don't care how good of a job the design engineer did if the operation engineer is not diligent then best layed plans will always go up in smoke sooner or later.

The way the layout is at least one feed will be 50 feet, 2 at 25 and 1 2 feet, will 16 ga still work?

Hi 400e, in short yes. But, remember the fifty foot runs should be considered there and back, or a hundred feet. In that case I would go with 14 gauge wire, see Lee's calculations above.

Hi 400E, Did not mean to call you Ace. Visualize this. 18volts 10 amps Now using four 16 gauge feeders at maximum 25 ft each. Less than .46 voltage drop or your 3% good design Now factor in drops every 6-8 ft off the feeders. Then factor in the fact that your track itself is the equivalent of a #10 wire as another parallel conductor. I know how to use the calculator ( try one that let's you use 18 volts and multiple conductors) And I do understand low voltage wiring.

Hi Lee, I don't think I every said .9 amps max. Maybe 4. And I did say before, that if you need it, that's fine with me. I can understand why you are doing it. And A400, For your 50' run you could go with a parallel run of two 16s. Or a loop. I also think that a lot of people ignore the track into their calculations. I think that the original post was about wires burning. We did kind of get off track. I do not thinks that Lee's # 8's will ever get hot enough to start a fire as long as his joints stay intact. But a small break and gap at 10 amps could very quickly and his circuit protection would never know the difference. A smaller wire might melt just enough to stop the arc. That said, go with what you knows works for you. I would rather see heavy wire than someone misinterpret my advice and get hurt. Having run thousands of miles of wire, I can not help looking at the cost, time, value equation. It's in my blood. Back to wiring my switches today. FMH

Actually have one more question for Lee . What are you doing for returns (common)? With all the thought you put into this and "proof is in the pudding", it does work, I can not imagine that you are using the Atlas track alone. It have to assume you are mirroring the feeders.