OK, I measured the track voltage. So, . . . am I done?

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.

I added drops about every 6-8 feet on my track, the main platform has around 400 feet of track and I have 70 drops in total.  Voltage drops are virtually non-existent, and I have no issues running the most power hungry locomotives I own.

17.3 volts….17.2 volts…17.1 volts and a $7.00 voltmeter what do you expect the accuracy and repeatability of that meter is….have you checked? Not anything I would be worried about or be seen in you layouts operation. Just run your trains. Transformer power rating is what it’s capable to supply on demand. Power = Voltage x Current.

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,

Mannyrock

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.

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?

Thanks,

Mannyrock

@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?

Thanks,

Mannyrock

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.

Thanks Big Kid.

Mannyrock

For kicks, if your meter has provisions to perform it, you might want to also measure the amp draw that the two engines are pulling.

You could also measure them one at a time to see which one draws more amps or add lighted cars and see how much more amperage they draw than just the engine(s).

If the trains you have run well at a constant speed around your layout then all is well. If the transformer is rated at 18V and was really set at full throttle the voltage measurement should be around 17V, not 5.1V. There is something off with the 5.1V reading but I would not be concerned about it.

I wonder if he meant 15.1? At 5.1Vac, I do not think that the trains would be moving much at all.