Wiring two MTH transformers to same layout

[Anonymous]

I want to run the same train on two loops of 0-27 track by switches from one loop to the other. Or, I may want to run two separate trains on the loops at the same time (each train would stay on its own loop without crossing over to the other loop). I used insulator pins on all 3 rails from the switch to the section of track leading from one loop to the other. I am able to run the two trains at the same time using two transformers (one on each loop), or either train on its own loop while the other train (loop) is off. This set up worked ok using an old Lionel LW on one loop and an MTH z1000 on the other (had to reverse the plug for the LW in the wall outlet to correct train shorting when crossing over). However, I now have problem of train shorting when crossing using a z1000 instead of the LW. Both z1000s are connected identical to their loop and I can't rotate plugs (wide prong of plug inserts only one way in outlet). What's wrong?

[willpick]

Tom, your two Z1000's are probably out of phase[:(]. Since you were able to phase the LW and one of the Z1000's, I'm confident that they (the Z1000's) are out of phase. To prove this, take a 12 volt bulb, connect it across the insulated gap. Then raise the voltage on the two Z's to 6 volts. If the bulb is bright, then they ARE out of phase[:(].
I'm assuming that you are using O 27 tubular track--- and that you are running conventionaly, using the controller box to vary the voltage-- If so, then all you need to do is reverse one set of wires at the output of the controller box, and you should be in phase.
I'd check the date code on the transformers(if it is there) I suspect that they are from different production runs. Lionel had a similar situation a year or so ago, where transformers built before a certain date were out of phase with the ones built after that date-- If this is the case, then I'd notify MTH via a phone call, email,etc. Hope this helps!

[spankybird]

Also double check that the common terminal of both transformers are to the outer rails and the red (hot) is to the center rail.

[FJ and G]

Tom,

Welcome to the forum.

[lionelsoni]

If the two transformers are out of phase, there are several possibilities for fixing the problem:

First be sure that the problem is with the transformers. About half the outlets in your house are wired to one phase, half to the other. Sometimes the two outlets of the same duplex recepticle are wired to opposite phases. Find out whether the problem still exists when both transformers are plugged into the same extension cord.

If this doesn't fix it (It probably won't), you could look around for a second outlet wired to the opposite phase. You probably won't find one; but you might get lucky.

You could reverse one of the plugs, by cutting it off and replacing it with an aftermarket plug, by filing down the fat pin, or by making an adapter that swaps the wires. These might be safe; but then again they might not if MTH had a good reason for polarizing the plug. Not knowing that, I would stay away from these solutions.

If you have no accessories operated from control rails, you could simply swap the wires between one transformer and the track.

However, in my opinion a better arrangement than connecting one transformer to each loop is to wire the center rail of each loop to the common of a single-pole-double-throw switch to allow it to be connected to either transformer. (Remove the insulating pins from the outside rails--they are not needed in any case.) This way, phasing becomes irrelevant; and the train can remain powered by the same transformer as it moves from loop to loop. Going from one transformer to the other as you have done is problematical, since, even if you got the transformers into phase, the voltages can still be different and fault current of some amount will flow in the transition. If it is great enough, it could erode your pickups.

[Anonymous]

Thanks to all you folks who responded to my problem. All of you had good stuff.
I was also able to get a hold of *** at MTH Technical Support (very helpful) and he confirmed that it is a phasing problem with my oldest z1000 transformer block. Seems that the the original batch of these blocks could have a phasing problem that was corrected in the newer batches. Original do not have +(hot) and - noted on the constant power accessory terminals; the later ones do. Anyway, he said to send the block to MTH for free repair even though it's out of warrenty (like a recall fix on your car). Nice of them. I wonder if Lionel would do the same.

He suggested, as most of you also did, to remove the insulator pins from the outside rails. This will also help with any variance in voltage between the 2 transformers as train travels accross the insulated center rail.

I'm getting another z1000 in a MTH set, so I'll try it out on the loop that has the old z1000 to see if I can get everything to run properly. If all is well, I'll send the old block to MTH for repair and I should be able to live happily ever after.

Thanks again,

Tom