Track voltage

Voltage is not the best measure for capacity. Amperage is the  best measurement for load. You have  180watt power supply. Watts equals volts X amps, so you theoretically have 10 amps max at 18 volts. If you have an ammeter, make some measurements with that to see where you stand.

@John H posted:

Voltage is not the best measure for capacity. Amperage is the  best measurement for load. You have  180watt power supply. Watts equals volts X amps, so you theoretically have 10 amps max at 18 volts. If you have an ammeter, make some measurements with that to see where you stand.

Thanks John, I thought it was the voltage drop that would affect the trains running? I’ll check to see if my meter measure’s amps also.

Gene

Gene,

You have a serious bit of good news there.  Your voltages are quite consistent regardless of where on the layout voltage is measured, and just as importantly whether the track has a load (engine, lighted car, etc.) on it or not.

The bad news is these measurements can't tell you how much extra capacity you have available.  With everything powered and running as things presently sit we can't determine of if your PH-180 is loaded lightly or heavily .  That's why measuring current in addition to voltage is also important.

If it's presently lightly loaded you should be able to add another train to the mix.  If heavily probably not.

From your pictures it appears that your meter should have a current measuring function, but current isn't measured the same way as voltage is.  You measure voltage between things; between the rails, between the terminals on a lockon, between the two wires leading to a lamp.  There is no need to break (open) any of these circuits to get a voltage measurement.

Current on the other hand is measured through things; e.g. through a lamp, through a motor; through an electric horn.  To do this you have break the circuit to the device and insert the meter, while in current mode, into the circuit, closing the break before taking the measurement.

This means that you have to disconnect one of the wires between the PH-180 and the track and insert the meter between that point and the point where the wire was formerly connected.

Let us know what you find, or if you need more help.

Mike

I use this little gem from Harbor Freight, very useful around the layout.  No need to break any wiring to measure current.

@Genemed,

You are right in thinking that voltage drop will affect your trains' performance. It looks like you have that covered well. If your wire was too small, or you had too few power drops, you wouldn't get those readings. I thought your concern was about how much load your brick would handle. To estimate that, you would need to know how many amps you are already using. When you reach close to capacity, just separate out one or two of your loops and power them with another supply.

Thank you all in helping me understand volts vs. amp current. I have the ph180 going to the lockon which feeds a terminal block. From that terminal block I feed the 3 closest loops. I then feed a mid table terminal block which feeds the other 3 sets of each loop. If I wanted to put an inline amp current meter should it go between the lockon and the first terminal block?

Gene

@gunrunnerjohn posted:

I use this little gem from Harbor Freight, very useful around the layout.  No need to break any wiring to measure current.

Thanks John. I’ll get one of these or use an inline amp meter.

Gene

If I wanted to put an inline amp current meter should it go between the lockon and the first terminal block?

Yes.

@John H posted:

If I wanted to put an inline amp current meter should it go between the lockon and the first terminal block?

Yes.

Thanks John, any suggestions on what to buy? I’m online researching now and it’s a bit confusing for me on what I would need.

Search for "10 amp analog AC panel ammeter" like this: On Amazon.

Baomain Ammeter DH-670 AC 0-10A Rectangular Ampere Needle Panel Meter Gauge Amperemeter

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@John H posted:

Search for "10 amp analog AC panel ammeter" like this: On Amazon.

Baomain Ammeter DH-670 AC 0-10A Rectangular Ampere Needle Panel Meter Gauge Amperemeter

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$8.99

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Thanks again John. I was looking at that last night but wasn’t sure. I guess it’s simple and does the job. For me the digital ones were very confusing to understand.

The most difficult aspect of using the Harbor Freight meter that @gunrunnerjohn recommends is trying to open up its heavy duty plastic packaging, let alone avoiding getting your hand sliced on a cut-plastic edge.

Once you've accomplished the opening procedure, the Harbor Freight clamp-on accuracy mirrors that of more expensive meters.

I have the pricier version of that meter because I also wanted to measure DC current out of the car battery to examine current drain from devices such as the Garmin GPS (that will run down the car battery if not turned off.)

In fact, for routine troubleshooting I use the Harbor Freight meter much more than my higher-end Fluke.

On all my main lines I have analog ammeters, similar to what @John H shows above, permanently installed.

I also have several other clamp-on meters, including one that measures DC current with the clamp-on.  The Harbor Freight is just so Handy, that I find I'm using it a lot.  As long as your power is pure sine wave, it tracks very well with my much higher priced Fluke.  Since I run the PH180 bricks, I have that base covered.   My workbench has the MRC AH501 Pure Power as well.

@gunrunnerjohn posted:

I also have several other clamp-on meters, including one that measures DC current with the clamp-on.  The Harbor Freight is just so Handy, that I find I'm using it a lot.  As long as your power is pure sine wave, it tracks very well with my much higher priced Fluke.  Since I run the PH180 bricks, I have that base covered.   My workbench has the MRC AH501 Pure Power as well.

Thanks John, would you say the Harbor Freight meter would be as accurate as an analog inline one?

Easily as accurate.  I found it to be surprisingly accurate when compared to other meters.

Thanks John, I’ll pick one up in the next day or so. It’ll be easier than mounting an inline meter. I’ll post the results when I get it.

Gene

I find it very handy for quick checks.  In truth, I haven't seen the need for a full-time volt or amp meter for the layout, I have the bricks, so I have a pretty good idea of what the voltage is.  I have a voltmeter and ammeter on the workbench for testing, that's when I usually want to know what's happening.