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look on the back of your transformers if your serial number starts with 0398 is the old model and the meter voltage on the transformer always reads more then the actual output, put an ac meter on the transformer output and with throttle close tell us what the voltage is, then increase the throttle all the way up and let us no what the voltage change is, it should read anywhere from 2 volts to maybe 26 volts depending on if there  is a load on it.

also when you first power it up read the amp led display on the front of the transformer it should read like o1 on the left and maybe 24 on the right , it will only show up for a second so you have to be watching it!

Alan  let me know what you find out maybe I can help you all!?

Alan

steam,

   Some of the 1st generation Z4K's had different read out fine tuning problems, I have one that is actually 3 Volts lower on the digital reading than the actual voltage being delivered to the tracks.  I set it at 21 to achieve 18 on the tracks.  I will probably never have it digitally fine tuned, I run DCS with that transformer all the time any way, and I purchased the Z4K from a OGR member at a very good price because of the digital problem.  The Z4K operates perfectly other wise.  If your Z4K operates properly for actual running, I would not bother to have it fine tuned.

PCRR/Dave  

Thanks for offering to help!  I thought at first it was just the gauges indicating wrong.  Today I hooked up to a track.  The right side handle works pretty well.  It turns the power off, the headlight of the engine goes off and the e unit cycles fine.   The left handle shows somewhere around 6 or so volts.  I forget exactly.  It was enough that with the handle in the off position the train engine sits with the light on, barely enough to keep it sitting still.  You can't cycle the e unit by turning the left handle on and off since it is on all the time.  Both gauges on both sides seem to be in-accurate.  It would be nice if there was a way to fix the left lever at least so it could be used for our second line.  

The transformers at my club (2 Z4000s) did this.  It is now sometime ago and I don't recall much except under load the voltage readings seemed ok.  This would be at the Z's themselves.  We had close to 100 feet of #14 out (and the same back) to the TIU's plus maybe another 25 feet the same to the most distant track block connections.

I was more concerned about the voltage drop to the engines (I had a 4-pulmor diesel, which, at a certain point on the most distant rails of the most distant block, could move itself when restricted to a 2-pulmor consist, but not move with the addition of a single passenger car.  Try 1.35 form factor (that's the heating and thus voltage drop in the Z output, relative to a pure sine wave, when set at 18 volts, compared to the same drop for the pure sine wave).  That form factor takes 2-1/2 in wire size number to overcome.  So #14 increased to #12 does not quite offset the form factor... not to mention trying to keep to the good practice of no more than 5% voltage drop in circuit.  You see, the raw output of the main Z coil is 28-volts pure sine wave, but only the envelope of the 18-volt wave is a sine wave.  The actual wave is somewhere between 300 and 600 cycles (the patent is written by lawyers)... I suppose the 400-cycle wire tables would be eye-opening enough.  (That info will actually be useful.)

Anyway, faced with the cost of improving this situation or the awkwardness of moving the Z's away from the refreshments bar, spurious voltage readings were of little concern to me, and I gave them no further thought... until now.  My best guess is that the meters involve some sort of voltage sensitive circuit coupled through a rather small capacitor(s), and amplified to drive the digital display by some off-the-shelf standard design.  In an otherwise idle circuit, but having the output handle set at 18-volts,  the active circuits (they were all somewhat bundled together, IIRC) induced voltage waves of opposite sign into the idle circuits, thus causing their meters to read less than 18-volts, or perhaps even causing them to read voltage when the handles were off... I cannot quite recall.

Look at this as being a perfect example of that old saying, "When you don't understand how something works, it will seem like magic."  Sometimes life will just be easier if you leave it at that.    (Sorry, I was in 6 hours of bumper-to-bumper 60mph to zero traffic today for 6 hours of lectures to get 5 PDH (the missing hour went to engineer jokes)).

--Frank

Well, it's a long story, but I read the posts before I decided that my computer was so unresponsive (jammed adware script, it was) that I sicced my anti-virus onto a complete computer scan... two hours later I replied to the posts I had read, without realizing that the real problem had been posted in the interim.  Namely, that the control of a conventional engine was involved and the e-unit would not release due to the amount of energy remaining in the left handle circuit.  So I unintentionally minimized your problem.

My club layout could not handle conventional engines, only DCS and TMCC, so I did not think of conventional.  I had said all the power wires were bundled together.  This was a simplification.  Actually, all the hot wires were bundled together, and all the common return wires were bundled together separately; the two bundles were about six inches apart on the same route.  It is this separation that caused our problem, IMHO... you see, each of our four circuits had 50 square feet of air between the out and back conductors of that circuits.  Now an air-cored transformer is not very efficient of space, but that does not mean that it is not effective at times.  Here that air-core is equivalent of about 7 square inches of iron core-- that's about 3 times the core area of a postwar ZW.  Granted it's only a single turn, but 3 turns on the core area of a ZW is about 1 volt.

Well, that's at 60 cycles... with DCS you can say that you may be transferring power at 400 cycles.  In that case, the iron core equivalent is about seven times more effective (400/60), so you may be transferring seven volts,  which definitely will interact even with the postwar electromechanical e-units.

So, what does that mean?  Well, if you are using star wiring and the OGR wire with an outer jacket over the out and back conductors, you don't have much air between out and back.  But not all do that.  Some say a lot of wire can be saved if the common return is made thru the outside rail and just one connection to the transformer(s) (or the load side of the TIU(s) at a point where the outside rail is closest.  With can motors and cruise control of DCS or TMCC or Legend locomotives, you may not notice any problems.  But this arrangement can result in the out and back path of the traction current being separated by a lot of air.  Look into this by making a scale drawing of the current path (on squared paper) out and down the track and back along the outside rail.  Whatever wiring layout you have, look at it in these terms and give it some thought.

--Frank

 

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