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RRampmeter readings

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  • Member since
    May 2005
  • From: South Carolina
  • 313 posts
RRampmeter readings
Posted by trnj on Monday, November 2, 2009 10:06 PM

I recently installed a RRampmeter and noticed that my DCC-powered engines draw only between .02 and .04 amps, according to the meter.  Am I correct in assuming this is correct?  (Engines: Walthers H10-44, Stewart VO-1000 w/ ESU decoder, BLI SW-7, and Bachman 44 tonner with ESU decoder.)

TRNJ

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Tuesday, November 3, 2009 6:58 AM

 Sounds about right, especially for the Stewart, Now put a decent size train behind them and check again - it will be higher, but not that much. Sorta confirms my overkill theory - no you do NOT need an 8 amp booster to run 4 HO or N scale trains. You don't even need a 5 amp booster.

                              --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
    November 2002
  • From: Colorado
  • 4,075 posts
Posted by fwright on Tuesday, November 3, 2009 12:17 PM

trnj

I recently installed a RRampmeter and noticed that my DCC-powered engines draw only between .02 and .04 amps, according to the meter.  Am I correct in assuming this is correct? 

TRNJ

I could be wrong, but I suspect the decimal point is a typo/misread.  I would expect readings from 0.2 to 0.4 amps for most modern HO locomotives.  If the 0.02 and 0.04 amp readings are correct, then there is an error somewhere.

just my experiences

Fred W

  • Member since
    November 2002
  • From: Colorado
  • 4,075 posts
Posted by fwright on Wednesday, November 4, 2009 10:15 AM

David

After doing some checking, I have concluded you are right and I was wrong.  I did not believe that newer drives had gotten below the 100ma threshold under normal conditions.  Doesn't matter whether on DC or DCC, the average current draw of the motor should be the same.  This analysis assumes decoder current is negligible in comparison, which should be correct for a non-sound decoder.  If decoder current was significant, decoder overheating would be an issue.

In checking, I noticed that Model Railroader reviews no longer include DC current draws while running - just slip and stall.  I had to go back to my '90s issues to find reviews that included current draws while running light.  And lo and behold, I came across several examples of reviews of locomotives drawing 20-40ma while running light.

my apologies

Fred W

  • Member since
    January 2008
  • 595 posts
Posted by mreagant on Wednesday, November 4, 2009 1:15 PM

Very interesting information.  How, exactly, would I measure amp draw on a locomotive using a standard mulit-meter?

  • Member since
    October 2005
  • From: Ulster Co. NY
  • 1,464 posts
Posted by larak on Wednesday, November 4, 2009 7:28 PM

Put it in series with one rail and use AC mode. The values will not be precise due to the waveform but are OK for relative indications. You might want to borrow a DCC meter for comparison and create a conversion chart for your meter.

The mind is like a parachute. It works better when it's open.  www.stremy.net

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