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Z vs ZW Performance problems and questions

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Posted by lionelsoni on Monday, January 29, 2007 10:35 AM
The size of the core determines how high a voltage and low a frequency each winding turn can stand before the core saturates.  The "magnetizing" current that flows in the primary winding to create the magnetic field lags the line voltage by 90 degrees, and therefore is at its maximum magnitude at the axis-crossings of the voltage.  Too little iron in the core will cause the transformer to draw high-current pulses at those times; but will have little effect on the load regulation.  That is determined by the series impedance of the windings, probably mostly the resistance of the primary winding.

Bob Nelson

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Posted by jkerklo on Monday, January 29, 2007 9:36 AM

It sounds like the ZW voltage is dropping when under load.

You might try measuring the voltage at the transformer while the train is running.  An analog meter works best for this, since you will likely see a changing voltage.

Might also try measuring track voltage at the farthest from the track connection while the train is running.  A difference in voltage between the transformer connections and the farthest track point would indicate a problem with track or wiring.

I have noted as much as a five volt drop from no load to full load for a ZW that was in good condition.  More than that would indicate a problem internal to the ZW. 

A look at the transformer core (metal plates) shows air gaps in both sides of the core.  Less iron means less magnetic transfer from primary to secondary, so output voltage drop from no load to full load is high. I, at first, thought that Lionel was just being cheap in constructing its coils, but later realized that it might be a safety design.  When the transformer output is shorted from a derailment the output current is self limiting; probably a good thing.

JK

 

 

 

 

 

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Posted by lionelsoni on Monday, January 29, 2007 4:52 AM

There was a fellow at a train show Saturday selling three Zs.  I was tempted; but I've really got all I need.

I tried running mine without the fixed 6-volt winding for a while; but I had to put it back.  The 773 Hudson really needs the extra voltage.  I believe that that locomotive represents a carryover of prewar voltage notions.

Bob Nelson

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Posted by Nick12DMC on Monday, January 29, 2007 2:29 AM

 mikegraz wrote:
I don't have any technical explanation BUT I recently viewed some of the older TM "great Lionel Layout" DVD's and more than a couple of Postwar collectors mention that the Z could really put out the power on all 4 terminals without problem where as the ZW was straining with a heavy load on all 4 handles.
So I would say that there is no real problem with your ZW. They seem to pale when compared to the Z.
Mike

Yes Mike is correct, I was watching one of the TM "Magic of Lionel" DVD's the other day. One collector mentioned that the Z put out more actual power than a ZW.

If the Whistle control is not working on the ZW try a spray of contact cleaner on the copper whistle switch contacts. This was the problem with my ZW, now the whistle works fine. Worth a try before you replace the disc's.

Nick

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Posted by PostwarMan07 on Monday, January 29, 2007 1:25 AM

I don't know too much on the subject but Im going to give it a shot....

Z tansformers give 25 volts to each of its 4 terminals.  I like to think of volts on a transformer as mph in real life (I think lionel actually put mph on the transformers in the pre and postwar years just for fun).  So if a moter could handle any amount of voltage I guess the Z could make that engine go 25% faster than the 20 volt ZW.  Since the postwar engines can't handle 25 volts over time we must stay within the 20 volt range.

There seems to be confusion about the 25 watt advantage of the ZW over the Z and why the Z is still more powerful.  Watts are totally separate from volts.  I think of watts as the transformer's capacity.  Lets say you buy a postwar train set with a scout engine and 3 cars.  It came with a 1033 90 watt transformer.  This is the right transformer for this set because the scout engine may only use 50 watts to run.  If you then buy a 2343 ABA santa fe and a set of streamline passenger cars you would need over 110 watts.  If you try and run it on that 90 watt 1033 it's going to run sluggishly and the transformer may overheat after a while.  Thats why lionel offers a 275 watt ZW.  You can run your 50 watt scout set, 120 watt santa fe set, and still have about 100 watts left to run accessories and switches on the two other terminals.  To make sure your layout runs smoothly use a spare transformer for accessories and leave the ZW for the trains (since these transformers are getting older this may be helpful in extending their life)

I hope this helps you guys and if any information I've said is wrong let me know.  I wouldn't want anyone getting the wrong info.

John W
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Posted by martinden on Tuesday, January 23, 2007 3:37 PM

Just as an aside ... The reason the Z (and other late pre-war transformers -- which Lionel dubbed "Trainmasters") went to a maximum of 24 volts was not primarily to operate standard gauge trains, which were almost at the end of the line for Lionel -- last year was 1940, I believe, and there wasn't much standard gauge offered at that point. 

The reason is the 167 whistle control, which contains a choke coil that absorbs about 5 volts. Lionel intended and assumed that most O gauge trains would be operated with the 167 in the circuit. Thus, with the track connected through a 167, it got 19-20 volts maximum. Pressing the whistle button by-passed the choke coil, raising the maximum track voltage to 24 or so. When the "Multicontrol Trainmaster" transformers were introduced in 1948 (RW, VW, and ZW), with internal whistle controllers, their maximum output was about 19-20 volts, though when the whistle control is activated, total voltage goes up to 24 or 25 because the 5-volt "compensating winding" is brought into the circuit. 

The 027 line included (generally) smaller locomotives which (generally) operated on lower voltages. (These generalizations could be discussed and dissected at some length, too much so for this post, right now.) Thus the transformers supplied with 027 sets usually topped out at about 16 volts, though there are exceptions. Thus, the 1033, which was included in the vast majority of 027 sets from 1948 through 1956, had a maximum output of 16 volts.

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Posted by stubbsO on Tuesday, January 23, 2007 10:37 AM

OK Dewey, will do. I did play with both at 20v and it seems that the Z still pulls better tha the ZW. I can only guess where 20v is on the Z. Could be that the dial is a smidge off on the Z, but still goes better. Maybe the ZW needs a check up. I just can't understand that even with a newer #8950 GP stalls out with the ZW, as that doesn't have nearly the run time as my other pw locos, and it's newer technology, parts, etc in that.  Keep the input comming. Thanks again

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Posted by A&Y Ry on Tuesday, January 23, 2007 8:52 AM

stubbsO

John mentions the word "toast" above and with good reason. You should probably limit your Z's operating voltage to about 18 vac which is plenty high for running either postwar or modern O-gauge trains. You can damage components in your engines and lighted equipment with voltage that is consistently too high.

As for your ZW, it is producing more than adequate voltage [20vac]. As regards the ZW's capacity, you need an AC ammeter connected in series [inline on the Hot center rail wire] to record the amperage output while you run a covey of engines and lighted cars to see if it will handle a 10 amp load [about 180-90 watts at 18 volts]. If the ZW falls short of handling a 9-10 amp load, then you need to get it checked out by an experienced Lionel Service Station Dealer in your area.

Again, clean well connected track with well connected feed wire{s} from the hot and common ["U"] binding posts.  

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Posted by 3railguy on Monday, January 22, 2007 10:08 PM

The voltage readings you are getting are normal. The Z is a prewar transformer designed to put out 6 to 25 volts for running big standard gauge trains. After WWII, Lionel came out with the ZW with a voltage range of 6 to 18 volts for the smaller O gauge trains. Be careful with your Z because you can easily toast postwar motors.

You only say your Z gives better pull than your ZW which is normal because the Z puts out higher voltage. If your ZW is truely sluggish, it can be a number of things. A sluggish ZW has a tendancy to get unusually warm or hot from resistance. Cleaning or replacing the rollers and mechanical contacts as others say helps if this the case. Loose or bent parts can cause semi shorts which also cause resistance. Shake it and listen for loose parts. WITH THE TRANSFORMER UNPLUGGED, open it and feel for bent or loose parts. Move the levers back and fourth while it is open to see if anything is binding. Another thing to check is to turn it upside down and sniff for burnt electrical smell. This indicates the windings may be shot. If they truely are shot, there isn't alot you can do except strip it for parts. Origional handles, terminal nuts, and lens caps are worth a fair amount of change.

As far as the logic of the 1033 and ZW is concerned, it was a matter of economics. the 1033 is a trainset transformer made as cheap as possible to run a the small train and a couple accessorys. Lionel kept the cost of the set low so they could attract people. A ZW on the other hand was designed for an expanded layout that draws more amperage. The amperage draw of two trains, illuminated passenger cars, layout lighting, etc, adds up quickly and causes voltage drop. Consider the extra 4 volts a booster to make up for the drop. ZW's were reliable, well made beasts in their day that could survive much more than 24 hour continuous use if the draw was 60% of it's 10 amp rating. These ZW's are 50 years old now and they do not preform as good as they did when they were new.

John Long Give me Magnetraction or give me Death.
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Posted by stubbsO on Monday, January 22, 2007 9:59 PM

 Back2Trains wrote:
The postwar trains are designed to run on 12-18 volts. If everything is in good condition, the postwar engines you mentioned should run very well on a ZW. 2023s were designed to be run with 1033 transformers which are 90 watt units with a maximum output of 16 volts.

 Not to argue with you but this does seem to kinda be contradictry in terms. My question would be , Than why did Lionel make a 250 or a 275 watt transformer? What would they be thinking with this logic if not just the 2023's, but with any other loco? Granted my stuff may be old and some of my track is better than some, and I have been playing with track to get consistant current all the way around, which I'm there at. Plus this only comes out in the winter. You can't tell me than Lionel didn't put these on the track and run them full blast for 24 hours at a pop, if not longer to test the durability of their product, because I'm sure they did, and Im sure they used the most powerful transformer they had on the shelf.

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Posted by Back2Trains on Monday, January 22, 2007 9:39 PM
The difference in performance is that the Z puts out 25% more voltage at full throttle than a ZW does. I would be careful running postwar and later near full output on your Z. You will shorten  the life of smoke units, light bulbs and maybe motors. The postwar trains are designed to run on 12-18 volts. If everything is in good condition, the postwar engines you mentioned should run very well on a ZW. 2023s were designed to be run with 1033 transformers which are 90 watt units with a maximum output of 16 volts.
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Posted by stubbsO on Monday, January 22, 2007 9:36 PM
Thanks for the input guys/gals? I've been trying a few different locos here, I have 2 sets of 2023's, 1 is a smoker more than the other, 2, 520's, a 681 steamer, 601, 611, 623 switchers, 2350 EP5, a newer GP that won't do squat with the ZW, better if I unplug and push it than around than to power it. All these run tons better on the Z than ZW. I would just think that with 275w would run better than at 250w. FYI, doing as previously posted with tests, at 20v the Z still pulls better than the ZW. Keep this topic running as it's good info. Thanks again
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Posted by ChiefEagles on Monday, January 22, 2007 9:33 PM
I've got 3 PW ZW's.  One was powering 6 dual engines today and had plenty of power.  Two scale SD80's and a scale Dash 8 dummy with lights and smoke was pulling 18 bathtub gons while other trains were running on the inner loop.  Two other scale diesels [Atlas] were pullung 9 K-Line diecast hoopers.  While two other engines were working sidings.  All on one side of one ZW.  The SD80s were flying and I had more to go but was afraid they might layover even on 072 curves.  Just as a note.  Why do you have 3 ZW's?  Going to seperate wiring for each loop [outer and inner].  They are already insulated from each other.  Run them on one ZW each.  The other ZW will power the sidings [they are insulated from the main lines.  A KW is powering the switches and accessories.  

 God bless TCA 05-58541   Benefactor Member of the NRA,  Member of the American Legion,   Retired Boss Hog of Roseyville Laugh,   KC&D QualifiedCowboy       

              

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Posted by Anonymous on Monday, January 22, 2007 9:13 PM
I don't have any technical explanation BUT I recently viewed some of the older TM "great Lionel Layout" DVD's and more than a couple of Postwar collectors mention that the Z could really put out the power on all 4 terminals without problem where as the ZW was straining with a heavy load on all 4 handles.
So I would say that there is no real problem with your ZW. They seem to pale when compared to the Z.
Mike
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Posted by lionelsoni on Monday, January 22, 2007 8:32 PM
What locomotive are you running?  The scale Hudsons need rather more voltage than other postwar and modern locomotives.

Bob Nelson

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Posted by A&Y Ry on Monday, January 22, 2007 8:27 PM

Thanks for the data Bob. I was not familiar with a "Z" by Lionel.

I see the specs now in Peter Riddle's Volume 3---same as the "V".

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Posted by lionelsoni on Monday, January 22, 2007 8:25 PM
The Z is a very rugged and simple 4-output Lionel transformer made both PW and PW.  Its output is specified as 6 to 24 volts at 250 watts.  Its (single) circuit breaker is rated at 15 amperes, the same as the ZW.  There are no whistle nor reversing controls, just 4 knobs.

Bob Nelson

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Posted by A&Y Ry on Monday, January 22, 2007 7:22 PM

I have three pw ZWs, now retired to test track and back-up service and they all variously read 18.8 to 20.2 volts [household voltage is 119.2]. All three have been refurbished over the past three to five years and served well for 15 years on a 5-track ,13 x 28 layout running large steamers with 30 car hopper trains, as well as dual-motored diesels. At the voltage you cited I believe your basic ZW transformer is okay.

If your engine is not running well, and it does run well with another transformer when set at 19-20 volts output, something between the ZW's output binding post[s] and the rails may be askew. Set your "Z" at 20 volts and see if the engine runs similar in speed and train consist to the ZW at 19-20 vac. Otherwise your ZW is losing output efficency in the secondary winding as soon as load is applied. I don't know why?

 

p.s: I cannot find specs for a "Z"---is it a Lionel transformer? The identity of the two pw Lionel ZW models, rated at 250 and 275 watts input, were noted by the wattage rating. The 250 watt unit had blue lettering on the ZW decal I believe.

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Posted by stubbsO on Monday, January 22, 2007 7:06 PM
Yes, they are the same on all, and this is using a volt meter on the post themselfs
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Posted by A&Y Ry on Monday, January 22, 2007 6:54 PM

Most likely, and based on your voltage readings, because the "Z" is producing and feeding the motor about 30% higher voltage than the "ZW" (25 vac / 19vac = 1.3159 multiplier or about 31%). Voltage is the pressure or motive force, amps or watts are the load, the wire,track and motor windings are the resistance.  Dirt, loose connections,etc, are VERY high resistance.

Is your voltage output on the ZW the same on all four hot posts---the A,B,C and D posts/throttles? You need to be sure that the binding post that your hot track feed wire out to center rail is connected to, is not broken or loose and providing a poor circuit. Also, check that your Common to outer rail is wired to a secure "U" post that is in turn still connected to the internal copper bus.

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Posted by stubbsO on Monday, January 22, 2007 6:41 PM

Then why will my Z pull a heck of alot more than the ZW? Why if I pull both in when cold and turn all throttles to full and check voltage, the Z has more volts than ZW? Or could it be like you said, the whistle rectifer is shot?

I just tried the whistle with a steam tender and won't blow like with the Z, but does work. Thanks

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Posted by A&Y Ry on Monday, January 22, 2007 6:36 PM

The initial 18 volts originally produced by a 1950s ZW is more than enough to run O-gauge trains that are on fairly clean well connected and wired track and engines that have clean power pickups and wheels. Most of us try to limit track voltage to 15-16 volts to prolong the life of incandescent engine, caboose and passenger car lights.

When the 275 pw ZWs came out 1/2 century ago, household voltage was 108-110 vac in most areas of the USA including TVA and local public power companies. Today, unless in a curtailled "brownout" situation, household voltage level is typically 120 vac and the ZW will reflect this roughly 10% increase and produce about 20 volts.

The 275 watt rating is power input to the primary winding rather than output at the low voltage secondary,which is how all postwar transformers were rated. The ZW will produce 180-90 watts at continous 30 minute running under load but will heat up considerably. Todays modern transformers are rated on output.

When you clean the units copper windings use an eraser and rub vertically with the wire. Then clean and spray with contact cleaner. Sounds like your unit is in pretty good shape if the rollers are still round and the power cord is not stiff and brittle---if it is a new one should be installed. Likely the horn/whistle rectifier is shot and won't work---not unusual. You can get a add-on Horn/whistle button box from Lionel or, you can install stud, anode-to-case+ diodes inplace of the old selinium or copper revtifier discs. A bolt-in with one electrical lead to be soldered.

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Z vs ZW Performance problems and questions
Posted by stubbsO on Monday, January 22, 2007 6:13 PM

I hope I didn't get taken to the cleaners on this, and I just don't understand electricity and how it works. I have both a Z and a ZW. The ZW I just picked up as the Z needs some work and has worked well for the last few years that I've had it. The Z wil put out 25 volts on all terminals at full power as I speak and the ZW only puts out 18-19 if I'm lucky. It just won't pull a loco around like the Z does, What gives here?

If their both rated the same except for the added 25 watts on the ZW, shouldn't they pull the same, if not alittle more on the ZW? Or am I overlooking something?

Could this be a recovered VW to look like a ZW, and how would I check this? I have pulled the tops off of both and cleaned the brass windings and the rollers look the same as far as wear goes on both. Thanks for the help.

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