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Hey Guys,

We had a lengthy and informative discussion two weeks ago, about my proposal to run about 12 to 16 separate sets of 18 gauge feeder wires from the main power supply wires in my  control box, out to the 5 separate track power blocks in my layout.

As discussed back then, the longest run of these sets of feed wires is about 8 feet.

I have completed wiring everything up as I proposed.

To make sure I had enough voltage in each track block, I broke the bank and bought a $7.00 Voltmeter at Harbor Freight.

By some random wizardry, I actually figured out how to set the red dial, and where to plug in the common and hot testers.

I have a used RMT Z-1000 transformer, which says on the box that it has a rated output of 18 Volts, and 100 watts.

I tested my transformer at the variable output posts, with the throttle turned all of the way up, and the meter read 17.3 volts.

I tested the farthest control block of track from my transformer, with power turned on only to this block, and the meter read 17.1 volts.   

I tested separately tested every other control block on the layout, and they each read 17.2 volts.

Interestingly, when I turn on all of the blocks at once, the farthest block also tests at 17.2 volts.  (Some sort of leakage I guess.)

So, I am just wondering, . . . am I done?

1.    Will adding more feeder power wires to the tracks create any additional benefits in any respects?     

2.     But also, if sometime in the future, I buy a more powerful transformer that is suppose to have say 150 watts, then what?   Will more power wires to the track be required to keep the voltage up at the max?  Or, to keep the wires from overheating?

Thanks as always,


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Your voltage readings are a nominal 18VAC. However, the real pudding is the voltage drop under a real load. At this stage, it isn't worth getting that pedantic over if you are happy with the trains operation. Go test run your most power hungry train and start running trains!

To directly answer your questions, you can always add more feeds. The only detriment will be what others think of you when you have a feed every inch of track.... A more powerful transformer doesn't automatically necessitate adding more feeds to a properly designed and executed wiring plan.

Now remember the command to run trains? If for some reason you have power related issues, come back to the forum here and let us know what is up and I'm sure we will get you straightened out. You are off to a fantastic start.

With only 8' of wire the voltage drop will be small unless there is a bad (high resistance) connection in a block. Unfortunately the the testing done so far does not provide meaningful operational data. The voltages measured are "open Circuit" with only the test meter current draw which is at most milliamps. To know the track voltage during operation there needs to be a load on the block. For a 100W supply that would be up to 5A. However the power supply will only deliver the amperage needed to run the train, I suspect that is less than 5A. The power supply wattage needed is determined by the current draw of the trains you plan to operate.

Each of the power districts on my layout have a 10A supply, a bit of overkill. Two steam engines and a  set of 8 passenger train can be in one block of a power district. The current draw for these two trains is between 6A and 7A (S gauge). With multiple 14ga feeders of about 20' I see about .3V drop.

Thanks for all of this great information.

I will turn on the electricity in all of the power blocks, put my two largest engines on the two ovals in the layout, put my flashing light caboose on the side track, turn the throttle all of the way up  so that the engines are running fast,  . . . and while they are all running,  test the voltage again.

I'll let you know what it reads.

Thanks again,


I think the 18 gauge wire will be fine. 18 gauge wire is rated at up to 16 amps at several feet, so with your run lengths likely it could handle 10 amps conservatively. Given you have blocks, you likely would blow the breaker (assuming you have a modern breaker) before the wire melted, especially given the number of feeders you are putting in.

The best test is under load, honestly taking an engine you know draws a lot (like an old Pullmor equipped engine) pulling a lighted car might show you if you have drops and is a better test IMO than a meter.

@Mannyrock posted:

OK Folks,

I don't have any Postwar engines or Pulmor engines anymore.   All of mine are modern can motors.

I did everything I mentioned in my last post, and ran the two largest engines and lighted caboose at full throttle, and I measured 5.1 volts on every section of my track.

So, . . is this bad, or good,  or good enough?



That should be fine. If you didn't see any significant slowing of the engines or the lights on the caboose/engines dimming significantly (ie where you notice it), then that should be fine. If you are running modern can engines then 18 gauge wire is perfectly safe the way you are using it.

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