In response to aflyer...
As I recall, the ZW-R uses a solid core, rather than one made of laminated strips of metal. Not sure if that has any electrical implications for the purposes of the operator. Externally, they should be the same.
I am not a flyer guy myself, but IIRC flyer trains cannot use the built-in whistle controls on the Lionel transformers. So, you might want to consider getting a Z rather than a ZW. The Z has four outputs but no whistle controls; it delivers up to 25 volts on each output; and it is much less popular (and therefore probably cheaper) than the ZW. However, the Z is just a box--it does not have the classic "football" shape.
Inside the ZW is a very reasonable place to put them. The other extreme, inside the locomotive, is also good. In fact, there is no reason not to do both: Those in the transformer protect any locomotive, your own or a visitor's, on your layout. One in your locomotive protects it when running on someone else's layout.
Bob Nelson
i guess if i wanted to i could open up my zw & just put them inside of it? might or might not, i have to get some small circuit breakers anyhow. so, i have some wiring to hide anyways. thanks everyone.
by the way, my atlas track came in today. it looks great. the only real drawback i can see is the connectors. it looks like they might get soldered just to avoid a future problem. if they would have made the ties a little thinner to help lower the track just a little it would have been great. no real complaints though other than a lionel 1666e that won't run on it because of the e unit cycling constantly. the same little engine does it on real trax too, but put it on lionel tubular track & it runs like a champ. any ideas on that one? i might just make another post out of that one.
Thanks. I could be tempted if its not too far. Where do you live?
Maybe this could help you with the concept: Telephone lines have long used spark gaps for protection against lightning. They're just pieces of carbon separated by a little air space. But, when lightning puts a high voltage across that gap, an arc happens, conducting the current around the telephone and limiting the voltage to something the telephone can stand.
The TVS does the same thing, but at a lower and more predictable voltage. Until a high voltage spike occurs, the TVS, like the air gap in the telephone protector, doesn't conduct current at all. When the spike voltage rises above what is normal for the circuit, that is, a few dozen volts, the TVS conducts (through the magic of semiconductors--there is no arc inside it) and shunts current around the train, limiting the voltage to something the train can stand.
Maybe a mechanical railroad analogy is useful: A railroad car sits on center bearings at the middle of its trucks. These are not very large; but they keep the car balanced and upright normally. But, if the train goes over rough or unlevel trackwork, the car can rock from side to side. To keep it from tipping over, there are "side bearings", often no more than chunks of metal on the sides of the car body and the truck. These don't normally touch; but, if the car tips more than a little, the small gap between the side bearing pieces closes up and keeps the car more or less upright.
An automobile also has stops on its suspension, rubber blocks or heavy woven straps that keep the wheels from moving more than a certain distance up or down from the body of the car. As long as you drive on a reasonably smooth road, they do nothing. But, if you hit a really big bump or pothole, they keep the suspension from being ripped off the car.
"if that was done with a piece of wire it would make a short, how does this differ?"
Nitro, this was also the hardest part of TVS usage to wrap my head around. All of our model train experience has told us not to let anything conductive touch cross the center and outside rails. Every time a piece of wire, or a screwdriver, pliers, etc, touches those two rails, bad things happen. So to wire the TVS across the A, B, C,& D posts and the U posts on my ZW was a HARD thing to do. But I trust Bob N--he hasn't given me bad advice yet! If he lived closer, I'd buy him a
thanks Bob, i understand now.
Took Bob's advice and got TVS's. Never had a problem and actually do not worry about my engines and their electronics. Worry free operations.
God bless TCA 05-58541 Benefactor Member of the NRA, Member of the American Legion, Retired Boss Hog of Roseyville , KC&D Qualified
Unlike a piece of wire, the TVS does not conduct electricity until the voltage across it reaches the value that it is rated for. Then it conducts like crazy, keeping the voltage at that value, which is one that will not harm the electronics.
The TVS voltage rating is selected to be just a little higher than the maximum instantaneous voltage that would normally be on the track, which is not the same value that we use to describe the transformer output. For example, when we measure 20 volts coming out of the transformer, the instantaneous voltage is actually going up to about 28 volts.
let me make sure i've got this right. i could solder one side of the tvs to one terminal of a lionel track lock on & the other side of the tvs to the other? if that was done with a piece of wire it would make a short, how does this differ?
Hi guys,
Back to the part about the ZM trnansformer, Model R, what does the R mean. Yep I am a flyer guy considering a ZW for my layout.
Thanks in advance,
George
I don't think we have answered all the questions here:
How many TVSs? One for each separate voltage source. So, if you're using two of the outputs of a ZW, you need two TVSs. Each TVS goes between the individual output terminal (A, B, C, or D) and the common (U), that is, one of the two leads of one TVS goes to, for example, the A terminal and the other of the TVS's two leads goes to the U terminal. They don't need to be at the transformer if another location is more convenient; but they still need to be connected to the wires that come from those same transformer terminals.
Use 15-ampere or smaller circuit breakers for a ZW.
Ok then, guess I'll find some other use for those cords.
Thanx!
The power cord is soldered into two eyelets. I don't think 14 ga wire will fit in the eyelets.
16 gauge is big enough. You are only drawing about 2.5 amps on the power cord.
Bruce Baker
servoguy I go to Home Depot and buy an extension cord for $1 and cut off the female plug. This cord should be 16 gauge. It is not a question of how much current the ZW draws, as this is relatively small, but how large should the cord be so that it is protected by the circuit breaker in your house. Bruce Baker
I go to Home Depot and buy an extension cord for $1 and cut off the female plug. This cord should be 16 gauge. It is not a question of how much current the ZW draws, as this is relatively small, but how large should the cord be so that it is protected by the circuit breaker in your house.
Having said that, would there be any value in using 14 ga.? I have a few of these stashed just for this purpose.
Generally, use 14 AWG, since the internal circuit breaker is rated at 15 amperes. However, if you add separate circuit breakers to the individual outputs and those breakers are smaller than 15 amperes and you can tolerate any increased voltage drop due to the smaller wire, you can use 16 AWG for 10 amperes, 18 AWG for 7 amperes, 20 AWG for 5 amperes. Adding such breakers is a very good thing to do, whether you stay with 15 amperes or reduce the current rating below that.
Do not expect circuit breakers or fuses to save your locomotive electronics. A short circuit such as a derailment means that the current is flowing around, not through your locomotive. If the locomotive itself ever starts drawing high current through its electronics, it is already toast before any fuse or circuit breaker opens. Protect your locomotive with a transient voltage suppressor, which prevents the voltage spikes which are the real threat to the electronics. Protect your transformer and layout wiring with circuit breakers and fuses. Thermal circuit breakers do as good a job as faster types or fuses and don't trip unnecessarily on short overcurrents.
i'm talking about the wire from the transformer to the track. i'm wanting to put a small circuit breaker/fuse in line so that a derailment doesn't fry my electronics in the engines. Bob said to use the current rating appropriate for your wiring and transformer.
Reading through this post, the question that comes to mind is, in replacing the cord on a PW ZW, what gauge wire should you use?
lionelsoni The 1.5KE36CA is the TVS that I recommend: http://cs.trains.com/trccs/forums/p/102002/1185776.aspx#1185776 Unless you don't mind changing fuses, get automatically resetting thermal circuit breakers from an auto parts store. Use the current rating appropriate for your wiring and transformer.
The 1.5KE36CA is the TVS that I recommend: http://cs.trains.com/trccs/forums/p/102002/1185776.aspx#1185776
Unless you don't mind changing fuses, get automatically resetting thermal circuit breakers from an auto parts store. Use the current rating appropriate for your wiring and transformer.
i'm getting ready to start my layout. i'm going with the atlas sectional track (without the roadbed). my layout will be a 5x9 or 5x10, & able to run two seperate trains at the same time. just say two basic ovals (o54 & o45). i have a couple of questions.
the first being, how many tvs do i need? one for the hot & one for the ground (common), or just one on the hot?
the second is, what size automatically resetting thermal circuit breakers would i need using a zw275? i don't know squat about electronics.
I thought you meant that you got a type R transformer. You got a type ZW model R, which is an entirely different thing.
it has the zw 275 type R core in it. it's a riveted core. you can see it in a earlier post that i made that has a link to a picture of it.
i have one question. the whisle controllers only work if i push them about half way. if i push them futher the whistle stops on my k line. pushing the whistle lever half way my mth steamers it will start whistling & then i can push the whistle lever all the way forward & it will still work. is this normal? it has the rectifier discs in it. i haven't tried my postwar lionel air whistles yet.
Are you sure you have a type R? The type R had two independent outputs, two circuit breakers, and no whistle control.
what kind of fuses & tvs are used? i have a few postwar, one prewar, several mpc, one k line, & a couple new lionels & mth engines with all the electronics.
where do i get the tvs's & fuses? any part numbers?
Jerry,
Some of the ZW cases are smooth and shiny, while others are somewhat textured and spotty. Armor All sometimes works to bring up the shine, but just be sure to buff it off.
i received it yesterday. it is a type R & is very quiet. althought it doesn't have an R on the base plate or case, it is a type R. i read somewhere that lionel only marked the first couple of years of the type R transformers, until the last couple years when it was on the case below the wire contacts.
it has a new lionel cord, new rollers, & a new circuit breaker. i would bet the whisle rectifiers are new too. all this cost me under $175.00 including shipping.
is there any way to polish the cases or do they all look kinda spotty?
I believe that you did very well and I am sure that you will be pleased with it. I have a couple of ZW transformers that I have had for many years. During the Holidays, I set up a double track layout around the tree. Sometimes 1 of the loops is Standard Gauge, other times they are both O gauge. I have never had major transformer problems, except wear, mainly because I don't overload them. I know that the ZW will run 4 trains, but I have a lot of assesories and lighting. When I run a double O gauge loop, I hook 1 train up to the ZW, and use the 2 inner handles to regulate the speed for the trolley and gang car. Also I hook up a number of other assy. to it. I hook the other loop and some other assy. to my TW transformer. It also helps keep the young engineers at bay when they come over to run the trains. They have seperate transformers. Good luck with your purchase and remember a few years ago transformers were selling for a $1 a watt.
John
I agree that there is no good reason to replace a working copper-oxide rectifier.
A silicon rectifier has a higher forward voltage than a copper-oxide rectifier and therefore may in principle produce less rather than more DC voltage. The difference is slight, about .2 volts, and may be obscured by differences among silicon rectifiers' bulk resistance and variation in the copper-oxide rectifier's condition. A Schottky diode, whose forward voltage of about .4 volts is similar to copper oxide is a closer replacement for copper oxide; but it's hardly worth the trouble.
Much of the heat produced by older toy-train transformers is not due to any ageing on their part, but by the increase in utilization voltage over the years since the war of about 5 volts. Small transformers are typically designed to saturate somewhat at their rated voltage, in order to reduce their size and cost, at the expense of heating even with no load. Operating as they do on the edge, they are particularly sensitive to increases in line voltage. Every watt of heat that a postwar transformer produces at no load is a watt of increased heat that is not available under load. Older transformers run on 110 or 115 volts are a lot cooler than on 120 volts. But that is not easy to arrange.
In my family we owned both a 1953 KW and a 1957 ZW. The KW would hum, the ZW didn't. I bought a reconditioned ZW in 1995 and true to form it does not hum. A humming ZW would be considered a flawed unit today as was the case then. The KW was then and remains today a strictly single PW motor, modest train length unit.
As for running "hot" here's the crucial issue. (As reviewed numerous time in the various magazines ...) the 250/275 watt ZWs are really only capable of putting out about 166 watts continuous. That's two modest length single motor, modern trains. Start pulling a PW 2x vertical motor F3 w/ a string of incandescent passenger cars up a trestle + a single motor 6 car freight and your beyond the limit of that 55 yo electrical appliance. That aging ZW is going to get at least warm. That's not a good situation & your operations should be modified pronto. On our own layout the ZW is used only for signaling, running 3 PW trolleys+gang car, and some modest LED lights associated w/ some operating accessories.
All actual train operations are relegated to 3 MTH Z4000s ... as is the practice of numerous big train clubs and serious operators I am aware of. There are numerous reasons for going modern power, least of which is the safety factor of fast acting resettable independent circuit breakers on a very high current electrical appliance... but that is for another thread.
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