Z-4000 overloads, question for barry

Ed,

Having the TIUs in normal or super mode makes absolutely no difference as regards how many amps are being drawn. Unless you changed something in the way the transformers are wired to the tracks or changed some other wiring, running in Super TIU mode has nothing stop do with your power problems. The layout should work just as it did before instituting Super TIU mode.

Make sure that you didn't somehow connect tracks from one transformer to tracks belonging to another transformer, or connect together the two handles of one transformer. Doing anything lie that is sure to make for weird power problems and an unsafe operating environment.

The Z4000 has separate power supplies for each of its outputs, including the 10 and 14 volt terminals. The accessories and other things connect dot the 10 and 14 volt terminals are not contributing to the load on the transformer handles.

As I understand your problem, you are drawing 5.5 to 6 amps (according to the meter on the Z4000) from the first output on Z-4000 number 1. This output then shuts down. Forget all the other outputs for now. When the output shuts down what voltage and current do the meters indicate after the shut down, voltage and current? How do you get it back? Do you need to reset the circuit breaker on the transformer? If the circuit breaker is tripping it is possible that the breaker may be bad. They can go bad. If you do not need to reset the breaker but maybe turn the transformer off and on again there may be a problem with the transformer. There may be may other possibilities but lets check this out first.

Al

What is the ameter indicating on track 1 transformer 1 when you have no engines or cars on the track and the voltage up to 18?

It should be zero amps or close to it. If any more, you have a short in your wiring, TIU, or track 1.

Thank you all for responding to my post.

The circuit breaker does not trip. I have to turn it off then on for it to work again.

with all the engines and passenger cars on but not running at 14V the current drawn is about three amps. when I went to super TIU I found that some engins depending where on the layout they stoped last, upon power up would not be found or not on track. I did add jumpers between the three main tracks thinking this would improve the TIU RF signal.it seemed that this helped with the communication problem. but as I added more engines and passenger cars the current from xfmer one track one went higher. I will undo all the jumpers and see what happens.

but what about my communication issue?

any thoughts on that? thank you so much,Ed.

If there is any way to post your wiring diagram, that would help to try and diagnose the problem.

Rod

 I did add jumpers between the three main tracks thinking this would improve the TIU RF signal.it seemed that this helped with the communication problem. but as I added more engines and passenger cars the current from xfmer one track one went higher. I will undo all the jumpers and see what happens.

Good idea. Add them back, one at a time, reassess your current draw, and see if you can recreate the problem.  Then you'll know which jumper is the culprit.

edcava,

Now I am really confused. Origionally you said that you had 3 loops of track with a yard and a turntable using 2 TIU's. All was fine until you made the TIU's super TIU's. Now you say that you added jumpers between the 3 main lines to improve the signal and that is when the current went up and your troubles started. Then you started to swap lines between different tracks. ???

It sounds to me like you added a bunch of shorts. Remove all the extra jumpers and cross connecting wires and go back to the original 3 loops and yard. Does that fix you power problem. Forget about the signal for now and lets get the power problem fixed first.

Any time you have a weird problem do not bounce around. Go back to the simplest thing that worked and come up one thing at a time. It may take longer but it works.

Al

Thank you all again for helping with my overloading.

I removed all the jumpers(shorts). no change. so I removed everything from the layout.

I had: scale DREYFUS w/ 5pas. cars

         NYC 464 w/ 5 pas.cars

         WMshay w/4 log cars and caboose

          8th. ave. subway (3 cars all lit)

         penn. GG1 incl./ caboose

         penn. BB1  incl./caboose

         penn. L5    incl./caboose

         BN SD9     incl./caboose

         MLW ltl.joe incl./caboose

with all this off the track the current at 18V was 0.3,0.3 and0.3 from the three outputs with or without the jumpers. I could run all this at slow speeds but when I increased the speed the overload occurred. I then put back the SHAY,LTL JOE and a UPF3 w/ 15 cars and caboose and ran them at 50mph. the avg. current was 2.0,1.2 and 1.3 from the three outputs. output 1 is higher( I think) because that is the longest loop with 8 home runs connected.the others have only 3 home runs each.

so now I think my problem is just not enough power.(I could run even more trains).

can I wire the Z4000's for more current? ( I do have four ).

thank you Ed.

Just as a comparison, I run 375 feet of tubular track on a 14 x 22 G shaped layout using ONE Z-4000 and ONE TIU, all 4 channels.

Your current readings of 2 amps and lower are quite reasonable.

Each Z-4000 handle has a breaker ratedt at 10 amps. Each will put out 8-10 amps at 18 VAC (in command mode); 180 watts per handle, indefinitely thanks to being fan cooled.

I don't think you are short of power.

So with those low current readings, what is the problem? I am not getting it.

Rod

aluminum instead of copper wire?

Your current readings are fine. What makes you think you need more power? OK. You say the current with nothing on the track was 0.3 on each output. Now you increased the speed and the overload occurred, what did you increase the speed of since you had nothing on the track? Sorry, but is confusing. If you mean you increased the voltage remember you said you had 18 volts. Now you put something on the track to run and they run fine, the currents are fine, but you think you need more power.

You must find this fustrating and I am sorry but it is very confusing. You seem to have a problem when nothing is on the track but not when you put trains on the track. As Rod said the Z-4000 will put out a current of 10 amps and you aren't even close. It almost sounds like you have a bad Z-4000 for transformer 1 but you said you swapped transformers. Boy this is weird. Lets go back to basics. Check your wiring again especially from the Z-4000 to the TIU. Also check that your transformers are phased properly.

Al

You are only pulling 4.5 Amps total, that's not overloading a Z4000. Something else is wrong.

Try concentrating on one loop at a time. Remove all but one train from all your tracks. Run the train slowly then at speed (50MPH works) and watch for arcing at block joints and lights flickering or going bright there.

Note the power consumed.

Move the same train to the second loop and run again. Same things to look for.

Then run it on the third loop.

The Power draw should be close to the same on each loop. If power is higher on one loop, you need to find out why. Watch to see if it is higher all the time or at one point in the loop.

Let us know what you find.

Well I seemed to have caused some confusion. I apologize and thank everyone for trying to help.the basic problem is that when the track 1 xfmr. gets to 5.5-6AMPS the red overload light flashes and shuts down.(does not trip the circuit breaker).I replaced the xfmr. and the same thing happens. I will recheck all my wiring. could an engine be the cause?I will run one engine at a time and see.

I will get back to you. thanks,Ed.

Guys,

Let me throw out one more bit of information here about the Z4000, so that you all can take it and run with it.  That is, see if your mileage varies from mine, as the saying goes.  Anyway, the Z has six breakers-- the 4 external ones which you can see, which are in the hot (or red) outputs.  These are 3 and 4 amps in the accessory outputs (10 and 14 volts sine AC), and two at 15 amps in the two outputs of the main handles (variable volts, in an output shaped like the teeth of a comb, the length of teeth fitting within an envelope outline in the shape of a 27-volt sine wave).

If you will, the Z4000 is an electronic copy of the postwar ZW-- the patent for it says it's design is based upon the ZW.  The 27 volts comes from the ZW boost when blowing the whistle, plus the fact that we now use 120-volts as household voltage; then (postwar) it was 115 volts.  The Z4000 was built to run postwar trains, in effect (plus to apply special sequences of E-unit and DC-offset signals using pushbuttons).  And it was like two ZWs in one, for the two train outputs.  Let's say 10 amps on each, simplifying.  Now for the ZW you could buy an external magnetic breaker of 5 amps for each of the two main handles (again simplifying-- ie, just forget that the ZW's only breaker was 15 amps-- thermal --on the common return of all 4 return posts.)

If you just picture for a minute the Z4000 made out of all copper wire, instead of electronics, you might find it easier to picture what happens when the outputs of two handles become wired together outside the transformer.  Here I refer not the the common or black outputs, but to the A and D or the variable red outputs, as may be.  With the copper ZW, the joining of two power districts, A with D in effect, led directly back to the two corresponding carbon rollers on the single coil.  If these were set at different voltages, a difference of so many turns existed between them, and to each turn corresponded a difference of about two volts.

To make a long story short, in the ZW the full short circuit current would flow through only the turns between the two rollers (and out to the layout and back), without ever flowing through the 15-amp breaker in the common.  This was a maximum of about 45 amps (maybe 50), reduced by whatever additional resistance was present in the layout wiring.

If the postwar ZW had two ammeters in A and D, you could see that the train power woout on the track, a circulating short circuit current travels, say out on A and back in on B-- if say A is set to a higher voltage than B.  In this case, this short circuit current adds to the current on meter A and subtracts from that on meter B.  Other than making voltage A rather equal to voltage B, little effect would be seen in the voltages sent to the trains.  Of course the short bit of coil in the ZW, the several few turns, would begin to heat up.

So the UL people addressed this problem with a requirement.  In addition to the well-known requirement that the output of either main handle be limited to 180-watts (typically 10 amps times 18 volts in many applications by operators, as here), or corrected to it in one minute-- the UL also wanted the issue of the interconnection short circuit circulating current (above) addressed.  So there are a 5th and 6th electronic "breaker" located within the Z4000, one on each of the main variable output.  These are technically electronically supervised overload relays, and act after 24 seconds of uncorrected overload (from the patent).  The issue of circulating current is also addressed by this system (although the patent gives no verbal description of how this is done, or the timing it is tolerated).  I assume the same 24 second timing is used.

I think that one can assume that the meters on the Z400 "fail" to see circulating current in just the same way that the imaginary meters on my postwar ZW would fail to see it.  Making things electronic does not always change the underlying situation.  The Z4000's would use MOSFET's as the main gating devices, and these things will conduct in either direction, once triggered, IIRC, until a current zero occurs.  Its not like you have an output to the trains, and the the circulating short waltzes in, taking its time and causing a zero current crossing to shut the MOSFET down.  No, the current that is the sum of all currents starts in whatever direction it's going to go, right off the line.  Here current is essentially non-compressible, and it typically moves at 3/4 the speed of light.

It is not unusual to have the internal "breaker" be quicker than the exteral thermal breakers.  That explains the blinking or steady red light (I forget which).  Those Z400's in our club require pulling off all the handles, then resetting them to 18 volts.  We have weird sequences and amp numbers when power districts become bridged from rail creep, but since I know that's what it is, I don't pay much attention to the transformers except to shut them down quickly if a derailment occurs.

The reason for the two sets of breakers (we also have fuses, but enough co-ordination that the fuses generally don't blow) is historical, I think.  You see, during the development of big commercial breakers (was it 200 amp and up?) with adjustable delays supervised by built-in electronic circuits, we had a lot of problems.  Well, you see, short circuits tended to remove the voltage driving these new built-in supervisory circuits.  However, there has been  no sign of such problems with the Z4000 (I only even saw two reports of them being sent back in quite a bit of watching).

I hope this outline helps.  It isn't really necessary to make exact analysis of what is happening, just to understand its nature.

--Frank

uld flow out on each and register correctly, lets say.  But if A and B are bridged

The snippet on the bottom of my last post, under the signature, fits somewhere in the 6th paragraph.  Probably in the middle of the word "woout" [wo... out] in that paragraph.  But some more may be gone who knows where.

I think I needed to toggle wys/wyg.  My mileage varied.

--Frank

The corrected 5th (wasn't the 6th) paragraph above should read:

"If the postwar ZW had two ammeters in A and D, you could see that the train power would flow out on each and register correctly, let's say.  But if A and D are bridged out on the track, a circulating short circuit current travels, say out on A and back in on D-- if say A is set to a higher voltage than D.  In this case, this short circuit current adds to the current on meter A and subtracts from that on meter D.  Other than making voltage A rather equal to voltage D, little effect would be seen in the voltages sent to the trains.  Of course the short bit of coil in the ZW, the several few turns, would begin to heat up."

[The original lapse into terminal B instead of D is a typo, and also corrected here.]

--Frank

In the 3d paragraph above, the difference in output voltage was 1/3 volts per turn [not 2 volts as stated].  There were 42 turns and the variation was 14 volts in the part of the coil which was arranged for the rollers to contact.

The impression I wanted to convey was that it was easy with the ZW to get a one-turn difference between the position of the rollers in the setting of the handles, without noticing it in the output voltage.  The Z4000 has rather the same feel and small voltage variations, although a potentiometer is involved,  in its case.

--Frank

Interestingly, in the 10 or so years I've had a Z4000, I've never had the externally resettable breakers for the handles ever pop; it's always been the internal electronic.  Had forgotten they are there.

You are correct Frank in your comments on the ZW having the possibility of an unprotected short between handles.  This is a good reason for putting a breaker or fuse in every output (A,B,C, or D) of a ZW (or virtually any other standard transformer) even if you're absolutely certain the internal breaker (on U circuit only) is perfect.

With 2 Z4k's hooked to 2 TIU's hooked to 3 loops and a yard area, he could have a real can of worms if any of these are interconnected anywhere. 

I have 3 transformers feeding 2 TIUs feeding 6 "loops" and don't consider it a can of worms.  But, every bit of trackage is in a toggled block (70 or so) which facilitates isolating problems.

It sure would be great if somebody was near to edcava and could get over to him and look at what he has. It seams as if he has to have something crossed some where.

Al

I sure do thank everyone for their input.

I ran some of my enigens one at a time to see how much current they draw. approx. one amp each. I find that if I run fewer trains I am ok. and better if I run a passenger set on track three and not on track one. I still may have a wiring problem. I will check all my home runs again.I am using AWG12 copper wire. could the switches between loops be an issue? I am using both ross and atlas switches and switch power is from an independant supply. thanks.Ed.

Ed,

I am using both ross and atlas switches and switch power is from an independant supply. Could the switches between loops be an issue? 

Possibly there could be problems for any of the following reasons:

• If the switch tracks between the loops do not properly have their center rails insulated from one loop to another, allowing a connection between the two loop's power sources
• If the switch tracks are wired for non-derailing operation, using an independent power supply which is not in phase with the loop's power supplies
• If the power supplies for all loops are not in phase with each other
• If any one of the loops has it's Hot and Common wires reversed relative to another loop's power supply

In getting my DCS system going on my layout this last week, one day was spent with some bizarre symptoms similar to what has been described here.  I thought I had carefully phased all the transformers earlier, but something must have got past us.  After much trial and error, I ended up clipping the wide prong of the plug on one of the Z4000's, and plugging it back in "backwards".  This instantly and completely fixed the glitches.  Part of our problem, in retrospect, was that we thought of the phasing issue several times but didn't take seriously the possibility that one of these new Z4K's could have been manufactured with the plug on backwards.  So, just to let you know, it can happen.

I thought this was only a problem with some of the early Z4000's.

Were all of the transformers plugged into the same wall outlet?  It is possible to have wall outlets that are not on the same hot leg of the 220V line feeding your house, and this will create a "phase" (really "polarity") reversal.

Hojack,

Please post the serial numbers from each of your Z-4000s.

Dale M,

You raise a very interesting point. What DOES happen when you reverse one of the plugs in the situation you describe? The neutrals were tied together, and each side is ~120v from neutral, but 240 with respect to each other. I presume then that you could have a possible 44v max differential between the red outputs of the 2 Z4Ks. But when one plug is reversed, you now have the neutral and a hot leg tied together, right? That does not sound too healthy.

Chris

LVHR

There is no problem.  Reversing one plug reverses the polarity to match the other wall outlet.  The primaries of the transformers are completely isolated from the track, eliminating any concern that there may be 220V difference on the power cords.  Neutral is still neutral.

Whenever you have transformers with their outputs out-of-phase for any reaosn, you will have voltage ouput (between the "hot" outputs) that is the sum of their outputs.

So if you have two blocks, fed from two transformers that are out of phase, and let's say you have each transformer set to feed 20 volts to the track, when the loco's rollers cross the insulated gap, you have a 40-volt short.  Suppose you have passenger cars, which internally have 20-gauge wires---you SHALL have the internal wires of the car overloaded and, if you are using twp postwar Lionel transformers, there is NO circuit breaker protection.  Eventually, there'll be a fire.

Dale, your suggestion is interesting.  Not only are the ransformers not plugged into the same outlet, but they are intentionally on different circuits.  My electrician did a great job of setting up some big relays by the circuit panel: I have four circuits in the train room, and all the outlets are turned off with one wall switch by the door.  that way when I leave I know everything is off. I have one circuit in the repair bench room that is not switched, for battery recharging etc.

I would like some clarification concerning polarity and phasing, if you guys are interested in pursuing this.  I know when I wire house circuits I sometimes use 12-3 to run power to 2 separate circuits:  in this case it is important to be sure that the two circuits are fed from breakers on separate hot legs of the panel, so as not to overload the single shared common (white wire).  In that case you want the two circuits to be out of phase so that at any time on the AC wave there will only be 120 v.

My understanding was that "phasing" the transformers did not have anything to do with polarity; in my terminology, reversing the polarity would be making the transformer red output the common and the black output the hot, which would make your 3-rail track outside rail hot and the center rail common.  Phasing, I thought, had to do with the AC wave.  But if that is true, then why would phasing involve reversing the plug prongs (hot and common)?  Obviously my understanding has some gaps here.

There was a certain amount of fluky behavior when we were testing the track, hesitations, dropping out of DCS into conventional mode, and so on. But the worst thing that was happening was when the loco bridged the insulating pin between track run by what we later decided was the out-of-phase transformer and track run by another transformer: there was sparking and both transformers immediately shut down.

I never thought of this alternate-hot-leg issue when we were checking our system.  If Dale is right about this, then the MTH transformer may be just fine, and I should retract any implication of poor quality control at MTH.  Let me hold off publishing the serial numbers until we sort out whether I may have been premature in clipping the plug prong.

This would seem to add a whole extra dimension to the phasing process:  one would need to first be sure all the transformers are plugged into "phased" outlets?  Which perhaps is why when we first phased the transformers, everything seemed fine: they were not yet plugged into the outlets where they would end up on the layout.

RJR, Am I okay with my clipped plug or should I go back to my panel and change the circuit feeds at the breakers?

I use the term polarity, rather than phasing, because phasing usually refers to phase shifts between two sinewaves that may be anywhere from 0 degrees to 359 degrees.  In our case we only have two possibilities - 0 degrees (same polarity) and 180 degrees (polarity reversal).

If the branches are wired with a shared neutral, your electrician probably followed normal practice of trying to balance the loads on the two 220 legs to minimize current in the neutral, but this does create the problem you are having.  For your train room, you would prefer to have all of the outlets that feed your track transformers be on the same 220 leg. 

The problem is that if you are using 12-3 to feed two circuits, the circuits should be split to the two 220 legs.  If you have separate runs of 12-2 to each branch, you can use the same 220 leg since the branches do not share a neutral wire.

If you have 12-2 wire, you can ask the electrician to move the branch to the desired 220 leg, or you can use a plug strip from the wall to feed all of your transformers.  The plug strip is probably good for 15 amps (about 1750 watts), and that should be plenty of juice to drive several Z4000s.

On the other hand, reversing the plug to achieve proper polarity/phasing on the odd circuit accomplishes the same result without any downside problems.  In this case I would suggest that you boldly label the outlets and cut-down plugs to remind anyone that there is a potential problem.

hojack, it shouldn't make a difference which side of the 240-volt line your taking power off--the white neutral shouldn't be overloaded IF  the house is wired correctly

(I have come across a situation where a licensed but incompetent electrician used a 3-wire-plus-ground approach ("shared neutral") but put both breakers on the same side of the 240-volt line; that is wrong and a fire hazard!)

With respect to phasing, doesn't make any difference whether the transformers are on different circuits; what does make a difference is whether both circuits come off the same side of the 240-volt input.

In one sense phasing does relate to polarity.  Polarity on a 60-hertz line changes 120 times per second, and phasing means that both outputs are positive and of equal voltage at the same time. (Dale is correct that here we only have one possible misphasing 0 or 180)

The polarity of the output is dependent on the polarity of the input at any particular instant.  If the 120-volt AC line at a particular INSTANT is feeding positive to the left side of each identical transformer primary, the outputs should be in phase--if to opposite sides of each transformer primary, then they're out-of-phase

As to your question about the clipped plug, I expect that the transformer internally does not have any connections to its frame--that the two conductors go only to opposite ends of the primary coil--so it probably shouldn't make a difference.  PROBABLY!!  But be sure to mark the plug so you always get it right.

Thank you guys, this clarifies things.

I was talking generically about using one 12-3 to feed two circuits: this is not the case with the train room circuits. There should be no problem switching the train room breakers so that they are all on one of the panel hot legs, and balance these circuits with other circuits in the building on the other leg in the panel box.  

When I do so, I will replace the clipped plug on the Z4K with a new plug so that it can only be plugged in the right way.  Until then, I will keep it the way it is with the transformer plug reversed to compensate for that circuit being out of phase with the others.

Just to be clear to anyone reading this, it appears I was mistaken earlier and the MTH Z4000 transformer was NOT at fault.

If I am understanding all this correctly, should there be a suggestion to Barry that in future editions of his book, on page 68, where he describes the procedure for phasing transformers, that he add in his step #1 to be sure to plug all the transformers being phased into the same outlet to eliminate this issue?

thanks again

hojack, a caveat from one who's been there on replacing plugs:  it may be difficult to figure which conductor goes to the prong you filed down.  If you can figure a way to cut open the plug to do so, it might be a good idea. 

a whole other can of worms.    I still think changing the plug is a better long-term solution, i can't think of a labeling method that would be permanent and fool-proof.  will proceed with caution and not assume the prong is fed by the wire on the same side.  thank you for the heads up.

on page 68, where he describes the procedure for phasing transformers, that he add in his step #1 to be sure to plug all the transformers being phased into the same outlet to eliminate this issue?

Got it - thanks!

Hojack--

On the new plug, the wide blade will want to connect to the identified conductor.  Identified conductor?  The one that is different.  By having 3 raised fins molded into the insulation parallel to the cable, on the outer edge of one of the two wires.  They are small and hard to see.

RJR-- Glad to see you are still holding the fort.  I've been away for many moons.

--Frank

You have been gone a long while, Frank, good to have you back.

Hojack:  An Idea!  Before you cut the plug off, push a pin into the insulation on one side of the wire to make contact with the conductor (unplugged of course).  Take an ohmmeter and see which prong shows continuity with the pin.  That way you can tell which side of the wire goes to which prong of the plug.  Mark the side of the wire that is connected to the filed off pin.

Thanks guys.  good ideas, and i'll get that z4000 back the way it was made.    

I was working on the layout this morning and realized, the z500 brick that i have powering the TIU for the track that is run by that transformer is, of course, plugged into the same outlet as that transformer!  Yikes!  I can't help but wonder if something like this might be behind the difficulties experienced by original poster of this thread, but that's outside my qualification level.  

Clipping plugs just isn't going to cut it, and just compounds the confusion.  The only way to do this right is to first make sure that all the outlets serving the entire layout in any way, come off the same hot leg in the breaker panel: and only then to phase all the transformers to each other.  Live and learn!