If the transformer can make the locomotive exceed the desired speed at any point on the track, it's unlikely to be the transformer unless it's trying to climb a grade.
Note that he says it "takes off" and jumps the tracks! That doesn't sound like insufficient power to me.
Right, that was my point, it happens at different times, but where on the layout does it happen? Maybe he'll need a couple extra feeders to supply power.
He didn't say it happened at certain track sections, but rather "at times".
Bob Nelson
I guess a question would be, does the loco take off around the same area of the layout, or at random areas of the layout?
Again, it speeds up too fast on certain track segments. I can't imagine why everyone thinks this is a transformer issue!
BTW - One can buy just the Z-750 controller from MYH, PN 40-750C ($49.95).
For all, as Bob has noted several times in the past he has published an offset chart for approximate RMS sine wave equivalent voltages if one is measuring a chopped sine wave (like from a CW-80) with a standard RMS (root mean squared) ac voltmeter. Contact Bob for the chart if you are interested.
Regards, Roy
Checking a modern "transformer" with a voltmeter only is problematic, since some of them will put out full voltage when not loaded.
If this is the MTH 30-1025 set from 1997 it is likely the transformer controller has failed. The Z-750 uses a separate transformer that plugs into the track power controller and most likely the controller has failed. There are a couple of things you could try.
You could try just operating the caboose (If it is lighted - my 1997 MTH catalog does not specifiy if the caboose is lighted or not) and see if the light intensity smoothly changes with the position of the controller handle as it adjusts from minimum to maximum voltage.
You can also try the same with the locomotive. As I recall all the earlier MTH locos (as do the newer ones) start up in neutral and since this set predates use of LEDs for lighting, the loco headlight should also vary smoothly with the position of the controller handle.
Otherwise you can try an 18 volt lamp (separately or using an accessory) or AC voltmeter tied to the transformer to do the same thing.
If the controller is faulty then you will not see smooth variation of the lamps or voltmeter.
If the controller operation with lamps or a voltmeter is smooth you may have a binding problem with the locos drive or drive rod mechanism (the 1997 1025 set is a Huson steam loco), particularly if this loco was used on a floor layout and has pet hair, carpet fibers, etc., caught up in the bearing surfaces. You can also remove the shell and check that the grease has not hardened in the motor drive worm ad spur gear although modern lubricants do not harden up like the older ones. If you disassemble it leave the motor loose and see if it runs smoothly on the Z-750 and move the drive wheels and rod assembly by hand to see if it turns smoothly.
Good luck!
The power rating that you need depends on the train(s) you are running and not at all on the length of the track. I would not rule out the possibility of a defective transformer. If the problem is in the track joints, I would expect the train to run faster near the point of attachment of the feed from the transformer and slower far away from that location.
If the locomotive "takes off" and runs too fast, it's not transformer capacity you lack.
I'm guessing you have poor connections between track segments and when it gets onto one that has that has more voltage, it speeds up and jumps the track. I'd start by cleaning all the track ends and crimping the pins correctly. I use tiny SS rotary brushes to clean the inside of track connections.
Gentlemen,
I purchased a NYC Super Freight Express train set for my children some years ago and have not been able to have them enjoy it as it seems to be having electrical issues with the transformer. The set came with a Z-750 which provides 75 watts of power but when I hook up the set the transformer seems to become sporadic and the engine will at times "take off" and jump the tracks. If I am using too much track could it be a matter of this being caused by inadequate power for the amount of track I'm trying to use? I hate that this train stays stowed away due to this problem so I guess what I'm asking is - would a larger, more powerful transformer correct this issue and allow me to enjoy this train? I am new to model railroading so I appreciate your patience.
Best Regards.
Kurt
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