MTH Z1000 transformer - Which wire is positive?

There is no positive or negative in alternating current toy trains. An inline fuse can be inserted in either or both feeder wires.

 

 

 

 

That's what I thought Arthur but the DCS manual on Pg. 15 says to connect the black negative (-) and the red positive (+) to the black and red banana jacks (respectively) on the  Fixed Voltage input on the TIU.

 

Why would the manual differentiate the two wires?

 

 

It will only matter if you are adding more transformers and want to keep them phased.  If you use the MTH adapter you don't have to worry. 

 

The internal barrel is considered HOT (red) and the outside of the Barrel is considered common (Black).  So if your going to attach them without adapter find which wire is connected to outside barrel and that is black.

 

 The reason is the controller will place the offsets for bell and whistle on the center rail red output.  Additionally it keeps phasing the same as you add transformers since the Z-1000 and brick would be made to the same standard.

GGG,

 

One would think so.  Actually not all Z-1000 transformers are "in phase with each other.

 

I discovered this when setting up two Z-1000s on my layout.  There were issues when I connected a crossover between inside and outside loops.   Turned out that one of my two (brand new, came boxed in starter sets) was out of phase with the other.  AT the time, I mentioned this on the forum and others verified my findings.

 

Not wanting to cut cords, I ended up making an AC "adapter" cable to correct the phasing.

 

So Chuck, it's not an issue with one Z-1000 brick, but i would check to be sure if you add another.

 

Ed

Ed,  Yes Lionel had that issue with Bricks too.  By design they are suppose to be the same, factory errors occur.  I think you could have opened the brick and swapped the wires on the output to correct the issue.  G

I cannot tell you why MTH or any manufacturer writes things that are mis-truths.

 

The only logical explanation is that your equipment uses DC. Does it? I am not familiar with those items, so I may be wrong.

 

I can tell you that alternating current has no positive or negative reference, except instantaneously. That is why parallel supplies must be in phase, so that instantaneous peaks do not oppose each other. 

 

I would be greatly interested to hear what the engineers at MTH have to say about this issue.  I will gracefully back down from my rigid dogmatic stance if they can provide a solid explanation.

 

Over to you, Mr. Wolf...

 

Arthur,

 

While you are correct that here is no + and - in AC current, there is, however, AC Hot and AC Common. Traditional practice states that circuit breakers and fuses are typically placed in the Hot wire of a toy train transformer, just as circuit breakers (and, in the past, fuses) are placed in the Hot wire of home electrical systems.

 

Do you disagree?

Well I couldn't tell which was hot or common so I hooked up the Z-1000 to the TIU after cutting off the adapter. Couldn't tell by any writing on the wires which was which. 

Everything is working great. 

Should I be concerned and do more homework or am I safe because it's working well?

Great discussion guys.  Thanks.

Barry, as a licensed electrician, I agree that the primary of a toy train transformer has a hot and a NEUTRAL. These contacts are determined by the orientation of the line cord plug in the receptical. I disagree that the secondary of such a transformer has wires that can be identified as hot, common, ground, neutral, grape, root beer or salty.

 

If the wires to which you refer have voltages that can be measured with respect to ground or neutral, then the transformer is in violation of the NEC and cannot be used safely.

 

With that said, I understand completely the dilemmas under which professionals such as you and I find ourselves laboring with respect to the toy train power industry and the ambiguities that attend the terminology thereof.

I guess we have a big problem with the TMCC and Legacy power bricks in that case.  Both of them have one side of the secondary connected to the wall plug ground connection.

 

As neither a licensed electrician, or as some may have noted, particularly competent, I look at this from the perspective of a guy that does work on his own house and tries to play with trains.
Electricity appears at the breaker box in my garage. I take a wire that has a black wire a white wire and a bare copper wire and i run it to an outlet. My black wire is attached to a circuit breaker. I believe that's where the electricity comes into the wire. My white and bare copper wires are attached to bars in my breaker box via screws hold down things. In my outlet i follow instructions and attach the other end of the black wire to the hole that is labeled black. The white to the hole labeled white and the bare copper to the green nut....
Now my still limited knowledge calls the black wire hot, the white wire common and the bare wire ground.
Now i plug in my z1000. IF MTH made it Correctly, my black wire is connected to the center of the barrel connector(after the voltage is regulated from 120 to 18Vac.The outside of the barrel connector ultimately connects to my white wire. I connect the Z 100 to a mth  barrel to banana adapter. The black wire that brought electricity into my house is now connected to the red wire of the connector. The white common wire is now connected to the black wire of my mth connector.

My understanding is that now it is critical to keep this convention through your model train layout, especially if you are using a control system or multiple transformers on isolated loops. Keeping this covention, is as critical as not swapping red and black, in a DC circuit.

In short. Follow the manufacturers recommendation. I will leave it to someone else, to post on how to make sure the vendor didn't make a component damaging mistake and mess up the "phasing", which I think boils down to swapping my black and white wall wires.

Actually, the secondary of the transformer for most train transformers is totally isolated from the primary, and there is only a magnetic connection between the two.  The ones I mentioned are a special case, as they use the ground to propagate the TMCC signal, and thus have to have it connected through.  I believe there is a small resistor inside the transformer to provide excess current protection between the connections, at least that's what I measure.

 

 

i always thought TMCC signaling depended on the secondary (outside rail) NOT being connected directly to earth ground?

 

Or do you mean the way they are coupled inside the Command Base?

You're correct, the connection from the command base P/S to the ground pin of the outlet is the OTHER side of the signal that is received by the antenna, not the signal that travels along the rails.

 

I told you which was which in my post.  Why ask questions if you won't use the advice?  Outer barrel was black common.  Inner was Hot.  G

"...my black wire is connected to the center of the barrel connector(after the voltage is regulated from 120 to 18Vac.The outside of the barrel connector ultimately connects to my white wire..."

 

Nope.  There is no connection between those wires.  The voltage is not "regulated." It is "transformed."  It is not a metallic connection; it is an inductive connection.

 

A metallic connection, without current limiting (see next post) would be illegal and dangerous. 

 

 

 

Gunner John said: "I believe there is a small resistor inside the transformer to provide excess current protection between the connections, at least that's what I measure."

 

John, you are absolutely correct, and pointing out that the connection is current-limited is the difference between "connected to ground" and "uses a ground reference for RF signals."

 

Thank you for solving the riddle for us.

i did the same..center wire to red..but really doesnt make any difference as it is ac(single transformer application only).if you use additional transformers be sure they are in phase.

GGG,

 

He cut off the adapter, so at this point, the outer barrel means nothing.

 

Chuck,

 

If you look at the wire very closely, you will see that there IS some writing stamped into one of the two leads, and the other lead has a slight ridge in the plastic if you run your finger over it.  The wire with the stamped writing is Black, the wire with the ridge is Red.

 

Ed

Ed, of course, but I responded after he posted so one would assume you wait for an answer or 2 before taking action.  G

Arthur,  As stated it doesn't matter on the input until we get to phasing.  Since the TIU is a single unit with 4 inputs and 4 outputs phasing could come into play.  So for transformers with red and black plugs (MTH, LIONEL, K-LINE, etc...) it makes sense to tell the user to go red to red and black to black.

 

The original poster won't have an issue until he gets a second transformer and sets up block control.  At that point if the transformers are not phased he will find out in short order.  Pun intended.  G

 

I had already cut off the barrel before starting this thread thinking it didn't matter. Hence my original question about which WIRE was hot... I wasn't asking about the barrel. I could have worded the original question better.

 

Thanks though G.

 

Chuck

 

 

Thank you Ed.  I went out and checked and sure enough you were right. Thanks!

 

Chuck