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DCC

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  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Wednesday, October 17, 2012 4:01 PM

Paradise Railroad

What does it mean when the track voltage Measured with a RAMP meter shows 25v AC and DCC?

When you say DCC do you actually mean DCC (digital command control) or are do you mean DC (direct current, as opposed to AC, alternating current)?? As several folks have noted, normally a DCC system puts around 14 volts AC on the track. A DC power pack for non-DCC engines normally peaks around 12 volts, but some designed for 'large scale' trains as used in garden railroads may get up around 18-20 volts I believe.

Stix
  • Member since
    February 2002
  • From: Reading, PA
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Posted by rrinker on Tuesday, October 16, 2012 9:46 PM

 The Atlas system was somewhat known for producing excessive voltage, because the Generator is a bit too high - for HO and N scale anyway. But 25 volts with just 17 in, almost impossible. If you are seeing a mix of voltages - sounds like you may have accidently connected another power bus, maybe for lights or turnouts, to the track power. Especialyl if it's only in certain spots.

              --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
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  • From: Colorful Colorado
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Posted by Texas Zepher on Tuesday, October 16, 2012 8:13 PM

Paradise Railroad

What does it mean when the track voltage Measured with a RAMP meter shows 25v AC and DCC?

It means there is something pretty serious wrong.  25V is too high even for G-gauge.  Quoting NMRA RP-9.1, "In no case should the peak amplitude of the command control signal exceed +/- 22 volts.". 

Max outout for Digitrax is 20V and Lenz is 22V.   I don't know the other vendors.  

Either there is a second source of power on the track or the DCC unit is malfunctioning and passing extra power through to the track.

  • Member since
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Posted by locoi1sa on Tuesday, October 16, 2012 5:22 PM

If its a Lenz system you can program the system for the voltage you desire. The electronics can step up voltage through the booster but if the power supply does not hold the amp rating at the stepped up voltage then the boosters will not shut down during a short. If it is not a Lenz system then check your power supply. Most systems other than Lenz will not regulate voltage and current from the power supply. Even O scale 2 rail runs good on 20 volt DCC systems with those giant 4 amp decoders. I know a G scale guy that runs his out door layout on 24 volt with 10 amp boosters. So if your O 2 rail or G scale you should be good, but anything else you have issues.

            Pete

 I pray every day I break even, Cause I can really use the money!

 I started with nothing and still have most of it left!

  • Member since
    October 2012
  • 2 posts
DCC over voltage
Posted by Paradise Railroad on Tuesday, October 16, 2012 5:11 PM

Most of the track has 17.5v showing DCC.    Just a few blocks have 25v showing DCC and AC present.  I have disconnected all other power supply's except the track power.  The layout is HO scale with an Atlas DCC system.  The Atlas generator produces 17.5v.  Has anyone experienced this issue?  If so what did you find was the solution.

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Tuesday, October 16, 2012 4:48 PM

I run an NCE PH-Pro 5 amp system.

My RRampMeter shows around 15 volts.

No way are you getting 25 volts on your DCC system.

Rich

Alton Junction

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    October 2006
  • From: Western, MA
  • 8,571 posts
Posted by richg1998 on Tuesday, October 16, 2012 4:24 PM

How about more info. What system are you using?

I measure about 14 volts at my home layout using the NCE Power Cab and about the same at the club with the 5 amp NCE Power Pro.

Rich



If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.

  • Member since
    September 2007
  • From: Charlotte, NC
  • 6,099 posts
Posted by Phoebe Vet on Tuesday, October 16, 2012 2:46 PM

My Digitrax Super Chief supplies just a little over 14V on my HO layout.

Dave

Lackawanna Route of the Phoebe Snow

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  • From: Orig: Tyler Texas. Lived in seven countries, now live in Sundown, Louisiana
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Posted by jeffrey-wimberly on Tuesday, October 16, 2012 1:12 PM

What scale are you running? 25v is way too high for HO. My Digitrax Zephyr only puts out 12v and that's with seven locos on the track.

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  • Member since
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DCC
Posted by Paradise Railroad on Tuesday, October 16, 2012 12:02 PM

What does it mean when the track voltage Measured with a RAMP meter shows 25v AC and DCC?

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