# Track voltage



## fooldancing (Sep 27, 2020)

I am currently running an MTH Pennsylvania 2-8-0 set with lighted caboose. What should I set the track voltage at from my transformer. I am running the DCS TIU system. I used to run G gauge, and I recently switched to O gauge.

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## DonR (Oct 18, 2012)

I found the manual for your set via Google



Manual for MTH Pennsylvania 2-8-0 set - Google Search



On Page 14 it states the output of the transformer is 14 Volts. I do no know whether the DCS systems uses
a different voltage. Perhapss GunrunnerJohn can give you specific advise. He is very knowledgeable of MTS systems.

Don


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## gunrunnerjohn (Nov 10, 2010)

The "standard" track voltage for command operation with O-scale for DCS and TMCC/Legacy is typically 18 volts. Most of the currently manufactured bricks have an 18 volt output for that reason from MTH or Lionel. Some of the MTH transformers like older Z-1000 and the Z-4000 will output up to 22 volts. That's OK for DCS, but TMCC/Legacy specify very clearly that 19V is the maximum track voltage. Command locomotives will run on less voltage, though if you get below 15-16 volts, sometimes stuff like electrocouplers start to be problematic, especially on older Lionel TMCC stuff.

If you're looking for a general recommendation, you won't go wrong with 18 volts on the track for any of the O-scale current command systems. That includes DCS, TMCC/Legacy, and all of the Lionel LionChief variations.


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## Lehigh74 (Sep 25, 2015)

While they are rated at 18V, I saw something recently that talked about setting voltage as low as 14 since it is easier on the electronics.


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## gunrunnerjohn (Nov 10, 2010)

The only thing I see 14 volts doing is making the electrocouplers unreliable and lowering the smoke output on anything that doesn't have the smoke regulator. I don't think it does anything significant for the electronics. In truth, there is a school of thought that under heavier loads the motor drivers are actually working harder than at 18V as they have to pass current for a longer period of time to achieve the same torque.


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## mesenteria (Oct 29, 2015)

Lehigh74 said:


> While they are rated at 18V, I saw something recently that talked about setting voltage as low as 14 since it is easier on the electronics.


Low voltage is THE ONE thing you do NOT want in any scale when dealing with DCC. That's why we urge people to have multiples of feeder wires touching the rails all over the place, to ensure high voltage. The reason is that it vastly improves the ability of the shorts detection circuitry to do its work protecting itself and all them expensive decoders.


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## gunrunnerjohn (Nov 10, 2010)

I am hopeful that low voltage is something I won't have on my new layout! I'll have over 100 drops for around 400 feet of track, that should do the trick.


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## fooldancing (Sep 27, 2020)

Thank you for clearing things up a bit. Now my question is, do I set the track voltage at no load or after I start the locomotive up? Sitting no load I have 17.7 -- 17.8 volts and once the train is started I have 15.6. I fear burning the electronics up if the volts are higher sitting at idle.

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## gunrunnerjohn (Nov 10, 2010)

18 volts at the locomotive isn't going to burn anything up that's operating properly. My bricks put out 18V, and I've connected them directly to the tracks for years.


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## fooldancing (Sep 27, 2020)

Do I make sure that it's 18v constant while the train is running, or, when it's setting idle? I'm sure that the volts drop once I got start up, while it's running at speed, and the smoke unit is on.

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## fooldancing (Sep 27, 2020)

Sorry for the dumb questions. I really do appreciate you taking the time to help me.

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## Lehigh74 (Sep 25, 2015)

Set it at no load. It doesn't need to be exact. I used to just put my ZW throttles at max (20 volts) and never had problems with my MTH locos.. Lately I put the throttles at 18 on the dial. I don't think it's critical that you measure the voltage either, but I've done it a few times and measured a bit less than what the dial indicated.


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## fooldancing (Sep 27, 2020)

Thank you Lehigh74. That helps a lot too. I am using a DC power supply that I used for my 1 gauge trains. 

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## gunrunnerjohn (Nov 10, 2010)

If you're running MTH, you don't have too much to worry about, they tolerate more voltage than the Lionel command stuff. You just set the voltage and then leave it for command operation. Note that if the voltage is varying a lot on the tracks, you either have a transformer loading issue or some wiring issues. When I run command, if I see the voltage at the track vary by a volt or more under load from no load, I'm looking at wiring and poor connection issues.


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## Lemonhawk (Sep 24, 2013)

17.8 to 15.6 underload seems to be a lot of drop. Where are you measuring this? Measure at the source and then at the various points around the track to see if the drop is between the track and the source which would point to something in the wiring that is eating a lot of power (heating), you might even spot the problem using a thermal or infrared thermometer.


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