I've replaced the cords in a number of ZW's without taking anything apart, other than the top cover. I have also replaced a bunch of rollers on ZW's and KW's without taking them all apart.
You can reach the power cord connections in the ZW without pulling the whole thing apart.
I HAVE BEEN TOLD BY A LIONEL REPAIR PERSON THAT AFTER THE COILS HAVE BEEN CLEANED , THAT IT WILL MAKE THE ZW OPERATE COOLER AND THE CONTACT ROLLERS LAST LONGER IF YOU APPLY A THIN COAT OF DIO-ELECTRIC GREASE TO THE ROLLER CONTACT AREA --ANY ONE ELSE HEARD OF THIS OR TRIED ?? THANKS, FRANK
Frank,
Whoever told you that does not know what dielelectric grease is, and what causes the heat in a transformer. Dielectric grease is an electrical insulator, and you would not put it on the roller contact surface of the coil, or you will get zero output from the transformer. There are conductive greases,and they are used to keep parts in electrical contact from corroding in harsh environments. A conductive grease on the coils would short them out because each winding is insulated from the windings next to it. As for the heat in a transformer, it is generated by the magnetic and electrical losses within the coil assembly itself. Notice that any transformer will get warm when plugged in, even if there is no load on it. The heat is generated by these losses, and no grease or anything else is going to stop these losses.
The carbon rollers fail because of mechanical problems, such as incorrectly installed rivets that are too tight, or bent when clinched over, causing the roller to drag instead of roll. Eventually the rollers get flat spots, or chip and crumble.
Larry
The carbon rollers also die of old age, I've had a couple of ZW's with perfectly round and rolling rollers, they were just worn down nearly to the arm. Funny thing, it's normally the right hand handle that has the most roller wear.
An important contributor to transformer heat is magnetization current, exacerbated by operation at a voltage higher than the transformer was designed for. This is usually the case with postwar and earlier transformers. Small transformers, such as those used with toy trains, are typically designed for a greater degree of magnetic-circuit saturation than larger transformers. This is considered a reasonable compromise, to make the transformer smaller and cheaper, and it is justified by the lesser concern for efficiency and the small transformer's greater ability to get rid of the resulting heat.
However, a modest increase in voltage can produce a disproportionate increase in heat. So it makes sense to lower the voltage put in if that is possible. One way to do this is with a variable autotransformer, like a Variac or Powerstat. I use a large isolation transformer for my layout, with my type-Z transformers plugged into the 104-volt tap. They stay pretty cool. There is a trick for doing it more cheaply; but I make a point of not saying how and of not recommending it.
Bob Nelson
I added a bell button to my PW ZW 250 when I was using MTH Realcrap I have since changed to tubualr and for some reason I can't get the bell button to activate the bell no matter how I connect it. I can get the horn/whistle button to activate the bell and the bell button to activate the horn but not the other way around like it was before. I haven't changed anything but the track does anyone have a clue as to what went wrong. I have the Lionel button encased in black.
Thanks
Kevin
Can't stop working on the railroad!
Have you swapped the connections to the new track? The ZW's U terminal should be connected to the outside rails.
Yes I did and thats how I got the bell button to sound the horn but it also slowed the locomotive down too. I just connected my MTH transformer back up and works fine. I like the ZW because the AC is on the base unit itself. It's ok for now though.
Really glad I found this! I'm in the market for a ZW and this has been very helpful.
Nick
Nick! :)
the nitro man I've never been around any of the Lionel zw transformers, but I've heard the zw 250's & the non type r 275's are loud & run hot. Is this true? I've been looking to buy one, but the only thing in my price range on ebay are the zw 250's, & I've never seen one in operation to know how noisy they are. can any of you give me the rundown on these? are they so loud i will be able to hear it over my post war trains, or do they just have a little hum? how hot do they get? what ever i get I'm going to replace the whistle rectifiers with diodes & replace the power cord. can the carbon rollers be replaced by me at home or do you absolutely have to have the Lionel press? thanks
I've never been around any of the Lionel zw transformers, but I've heard the zw 250's & the non type r 275's are loud & run hot. Is this true? I've been looking to buy one, but the only thing in my price range on ebay are the zw 250's, & I've never seen one in operation to know how noisy they are. can any of you give me the rundown on these? are they so loud i will be able to hear it over my post war trains, or do they just have a little hum? how hot do they get? what ever i get I'm going to replace the whistle rectifiers with diodes & replace the power cord. can the carbon rollers be replaced by me at home or do you absolutely have to have the Lionel press? thanks
Sixteen AWG is not heavy enough to carry safely the 15 amperes that the ZW circuit breaker will allow. You need 14 AWG for that, no matter how small the layout, even though 16 AWG may be heavy enough to avoid voltage drop.
There is no electrical reason to use stranded wire. It has the same resistance as solid wire of the same gauge. It is simply more flexible and easier to install. It is sometimes argued that it has lower resistance by those who mistake it for litz wire, which is a special stranded wire designed to reduce skin effect. Because of the greater average resistivity of having non-conducting air spaces in ordinary stranded wire, the skin effect on its greater cross-section is exactly concelled by an increase in skin depth. In any case, the skin depth in copper at 60 hertz (about 5/16 inch) is much greater that the radius of any wires that we might use for toy trains.
It makes little practical difference, but the original copper-oxide rectifiers have a lower forward voltage drop than modern silicon rectifiers. I would leave them in place if they work.
I think he means a ZW type R.
Bob correct me if I'm wrong but I have always been told that if it takes a second or longer the damage is probably all ready done. You need breakes the act faster than that I can't think what they are called but that type will not really protect the electronics of today. Now I do prefer the old ones my self
Life's hard, even harder if your stupid John Wayne
http://rtssite.shutterfly.com/
rtraincollector Bob correct me if I'm wrong but I have always been told that if it takes a second or longer the damage is probably all ready done. You need breakes the act faster than that I can't think what they are called but that type will not really protect the electronics of today. Now I do prefer the old ones my self
rtraincollector Bob correct me if I'm wrong but I have always been told that if it takes a second or longer the damage is probably all ready done. You need breakes the act faster than that I can't think what they are called but that type will not really protect the electronics of today. Now I do prefer the old ones my self rtraincollector Bob correct me if I'm wrong but I have always been told that if it takes a second or longer the damage is probably all ready done. You need breakes the act faster than that I can't think what they are called but that type will not really protect the electronics of today. Now I do prefer the old ones my self GREAT INFO GUYS. THE CIRCUIT BREAKER I WAS TALKING ABOUT ONLY PROTECTS THE TRANSFORMER NOT THE TRAINS THEMSELVES. THE RECTIFIERS THAT I HAVE FOUND OUT, WEAR OUT QUICKER THAN THE STUD DIODES WITH EVERYDAY USE. AT LEAST THAT IS WHAT THE OLDER GUYS TELL ME. TO PROTECT YOUR TRAINS YOU NEED A TVS VOLTAGE SUPPRESSOR. AS FOR THE 16 AWG. WIRE, A LIONEL EXEC. TOLD ME THAT A 16 AWG. IS MORE THAN WHAT YOU NEED FOR A BUS WIRE. DIFFERENT STOKES FOR DIFFERENT FOLKS. I GUESS EVERYBODY DOES THINGS DIFFERENT. WHATEVER WORKS. HAVE A GREAT DAY GUYS. AL
When a toy train draws more current than normal, it is almost certainly already damaged. That is, the high current is not the cause but the effect of the failure. So it is unlikely that interrupting the fault current, however quickly it is done, will save the train.
The thing that can kill modern electronics is overvoltage; and the cure for that is a transient voltage suppressor (TVS). The circuit breaker's job is to protect the transformer wiring, not the train, from overcurrent. A traditional transformer, like the ZW, can stand brief overcurrents because the thing that causes the damage is overheating. The stock thermal circuit breaker in an old transformer does a good job of modeling that overheating. It will allow a momentary current spike, but shut things down if even a small overcurrent persists. This is a desirable trait, avoiding "nuisance" tripping.
Modern "transformers" are another matter. They can be damaged by even very brief current spikes. That is why they come with electronic overcurrent protection built in. They wouldn't last long otherwise. But that protection doesn't help the vulnerable modern trains that they may be powering. For that, you need something like a TVS.
My experiences with MTH Z 4000 transformers are fine, but I found a limitation that maybe somebody else (Bob Nelson?) can explain: on the holiday layout at the St. Louis Museum of Transportation, using a Z 4000, the maximum voltage could be run up to 20 or 21 volts, but the average small train would take about 12 or 13 volts and 2 to 4 amps. However, for a trial, I ran a train consisting of a Lionel 2343 A unit and a 2333 A unit, each containing headlights, and nine AMT aluminum passenger cars, each of which contain two large-globe light bulbs. From wattage estimates given in the old Lionel instruction books, I figured this train would try to draw roughly 190 to 226 Watts. When the Z 4000 was cranked up all the way, the max indicated voltage was only 16, and the max amperage varied from 9.3 to 9.4. This told me that the maximum power put out by one side of a Z 4000 was about 150 Watts. By comparison, however, the full power of a Lionel ZW can be drawn from any one of the four handles, and will be controlled by the condition of the circuit breaker, which is supposed to be good for 14 to 15 amps. Therefore, for the short term, the Lionel ZW should be good for over 200 Watts, until it heats up and/or the circuit breaker trips.
Hi! Add me to the list of those satisfied with the ZW 275. Yes, at times, I do notice a very slight hum. It never runs hot. A few years ago, Trainland overhauled it (nominal fee) and replaced the original cord. Been working just fine.
PS....We run postwar Lionel......For sure, no noise concern.
HELLO MR. NELSON, ONE QUICK QUESTION. I HAVE ALREADY PHASED MY 3 LIONEL POST WAR ZW'S AND MY 1 KW. MY QUESTION IS. DO I LEAVE THE WIRES CONNECTED TO BOTH "U" TERMINALS AND "A" TERMINALS? SOMEONE TOLD ME TO DISCONNECTED THE "A" TERMINALS AND LEAVE THE "U" TERMINALS CONNECTED ON OF ALL THE TRANSFORMERS. THANKS FOR ALL OF YOUR HELP. AL
When you phase the transformers all you need is a connection thru all the U termanials. Connecting all the U is all you need as long as you know you have it correctly. ( you can change the polarity on the A and the U by reversing the plug in the socket. ) I always just add one at a time. If I can get a light between two U's then the plug needs to be turned over that is in the socket. ( I use a light with two wires for testing ( 14v bulb)
Wiring the commons (terminals U of the ZW and KW) can be tricky. If you simply wire all 4 of them together at the transformer location, you'll need 6 AWG wire (3/16-inch diameter!) for the common wire to the layout to be safe, because the return current can add up to 55 amperes in the worst case.
It's better not to connect the U terminals together among the transformers, but instead wire them to the layout using 4 individual 14 AWG wires, the same as you would use for the A-D outputs. That way each transformer's common return wire is fully protected by the transformer's own 15-ampere circuit breaker.
Another way to reduce the return currents is to run the transformers out-of-phase. You would probably not want to do this for any pair of track blocks whose boundary a train can cross. But it makes sense for isolated track loops or accessory circuits. For example, two in-phase ZWs require a 10 AWG shared common wire to handle the worst-case 30-ampere return-current sum, but two out-of-phase ZWs can share a 14 AWG common wire, because the worst case return-current difference is only 15 amperes.
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