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5 amps versus 8 amps DCC

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  • Member since
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5 amps versus 8 amps DCC
Posted by willy6 on Friday, December 1, 2017 1:49 PM

My HO layout is still in the building stage with most of the track laid and will end up with about 270' of track. I'll probably be the only operator, possibly one other. I have 25 sound locomotives and all wired turnouts are not DCC. I have a Digitrax DB150 with a 5 amp power supply from my last layout. Based on the amount of locomotives and amount of track should I upgrade to an 8 amp system?

Being old is when you didn't loose it, it's that you just can't remember where you put it.
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Posted by cuyama on Friday, December 1, 2017 2:15 PM

If the sound locomotives will be on live trackage all at once, you may need more power than 5 amps. But the better way to provide this is with additional 5 amp boosters, IMHO. Shorts will then have less chance to be catastrophic, wiring runs likely shorter, etc. The use of multiple boosters is wisely built into DCC technology and best wiring practices.

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Posted by richg1998 on Friday, December 1, 2017 2:56 PM

Get a RRampmeter and measure the layout current before you spend.

Do you know how much current a sound locos draws?

How many locos will you have sitting on the layout?

Sound can get annoying at times.

I built my own DCC amp meter and the club five amp NCE has run about ten locos. Current was around 3.5 amps. Most locos where sound.

When I put a dummy load on the layout, the booster tripped at about 4.97 amps as I recall so I know the readings are good.

I doubt you will run that many yourself. Be realistic.

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.

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Posted by selector on Friday, December 1, 2017 3:25 PM

I may get some pushback from this opinion of mine, but.................I don't think many of us can operate more than two trains, or four locomotives (the latter case comprising two separate consists, or MU's) at once.  We soon find it's too risky, nerve-wracking, or just too much un-fun trying to manage the trains effectively and still find a way to enjoy watching them.  We might try to let one run on the loop, a fast passenger train for example, and then switch and do other stuff with the main consist of our attention.  Add one more, totalling three, and you are now in some bother.

I say this, with quite a bit of agreement from others over the years here on this forum, because of two reasons:

a. Too many sound-equipped locos emitting sounds at once in a room of any size tends to lead to fatigue and annoyance.  We mostly mute or electrically isolate all but two or three locomotives at any one time to keep the enjoyment high; and

b. Due to this widely practiced tendency across the hobby of those who like sound locomotives, the amperage draw is usually below about 2 whopping amps for your typical layout.  This assumes you aren't also running lit passenger cars (Bachmann Spectrum heavies come that way, and Walthers' have a provision with an extra purchase of a kit...last I knew), or lights inside buildings, quite a few switch motors, and other accessories from the one bus under the layout.  If it's just two lashups of diesels with sound, or a couple of steamers and one pusher at the back of one of them, you'll have to watch that RAMP meter a lot to see the draw edge above 2 amps.

All this with variance, natch.  Bigger layouts, hosted ops sessions, six or seven long consists with MU'd locomotives, grades near 3%...yeah, you'll need more than those 5 amps you have currently. Maybe.  But 8 amps?

Naaaww....

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Posted by riogrande5761 on Friday, December 1, 2017 3:37 PM

 

selector

I may get some pushback from this opinion of mine, but.................I don't think many of us can operate more than two trains, or four locomotives (the latter case comprising two separate consists, or MU's) at once. 

I agree.  I would guess that 8 amps would only be needed for a power district where a lot of engines are being operated at the same time, not just sitting on the track, like a yard where several operators may be working.

The basic philosophy in DCC is on larger layouts, rather than having more amps, you set up power districts so that if many engines are operating, chances are they are powered in a different power district by another booster on it's own power supply.  So power is spread out over the layout using multiple power districts, say all of them 5 amp boosters.

Of course if you really want to melt plastic when there is a short, more amps will assist in that regard!  Stick out tongue 

Rio Grande.  The Action Road  - Focus 1977-1983

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Posted by RR_Mel on Friday, December 1, 2017 5:42 PM

I agree with all of the above.  Many of my locomotives have dual can motors and even running two trains with multiple locomotives with dual motors with sound I rarely see the current above 3 amps and I’ve never seen it over 4 amps.
 
If you have the ability to run more than two trains yourself keep your hat on, as you grow older your hair doesn’t grow back. BowBowBow
 
 
Mel
 
Modeling the early to mid 1950s SP in HO scale since 1951
  
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by rrinker on Friday, December 1, 2017 6:44 PM

 I don;t even need a RRAmpmeter to measure this - if you are only running one, maybe 2 traisn at a time - 5 amps is MORE than enough. Even if every train runs with 3 powered units, 5 amps is plenty.

 Brings up a good point though. Size of the layout has little to do with how much power you need. Only in the extreme does it matter - say you have a 50x100 basement (I wish!) and you run all around the walls, plus a few penninsulas. Even if you only ever run ONE loco on such a layout, you probbaly need extra boosters - because the bus runs will be too long for one single booster, even with fairly heavy wire, the voltage drop over such a long distance will be too much. On the other hand, if you have an 8x10 layout but it's designs such that 8 trains can run at once, you might need an additional booster. 

 I had no problems running 2-3 trains with sound locos on my 8x12 donut layout using an original Zephyr (2.5 amps).

                                                --Randy


Modeling the Reading Railroad in the 1950's

 

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

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Posted by BigDaddy on Friday, December 1, 2017 7:00 PM

Howard Zane's 2800 sq ft layout has sound locos I haven't seen a real operating session, but there are steam loco's with sound everywhere.   At least a dozen maybe two.  It is a great show for visitors, but if I were there as a lone wolf, I wouldn't want locos that I am not going to run this session or maybe the next 3 session making noise.

I would install switches to de-power various tracks, roundhouses and sidings.

If you are modeling the modern era with multiple head and rear end power, you probably still need 5 amps.

 

Henry

COB Potomac & Northern

Shenandoah Valley

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Posted by willy6 on Saturday, December 2, 2017 10:28 AM

Thank you for all the replies, I was concerned about the length of the track. I'm using awg 14 bus wires with feeder wires about every 4 feet. I feel comfortable now after reading the replies.

Being old is when you didn't loose it, it's that you just can't remember where you put it.
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Posted by BroadwayLion on Monday, December 4, 2017 11:28 AM

selector
I may get some pushback from this opinion of mine, but.................I don't think many of us can operate more than two trains, or four locomotives (the latter case comprising two separate consists, or MU's) at once. We soon find it's too risky, nerve-wracking, or just too much un-fun trying to manage the trains effectively and still find a way to enjoy watching them. We might try to let one run on the loop, a fast passenger train for example, and then switch and do other stuff with the main consist of our attention. Add one more, totalling three, and you are now in some bother.

 

You are correct. LION runs 12 subway trains on layout of him. Problem is him has only one head and only two (furry) paws.

LION AUTOMATED the layout of him. Is regular DC layout with fully analog automation. No computer chips were destroyed in the constructionof this system.

LION sits up in the 242nd Street interlocking plant and can move the trains in and out of the 242nd Street terminal just by using the home signals on the interlocking plant.

ROAR

The Route of the Broadway Lion The Largest Subway Layout in North Dakota.

Here there be cats.                                LIONS with CAMERAS

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Posted by MisterBeasley on Monday, December 4, 2017 12:43 PM

I agree with the need to evaluate how many engines you are actually running.  A few sound engines idling will not be as important as the load from running trains.  If you're running only 2 or 3 trains, 5 amps will be plenty.

It's a good idea to provide power switches to power off dead tracks when the engines are not in use.  This not only reduces load a bit, it also protects you from "rogue" engines if there's a hiccup in your DCC system.

Lighted passenger cars will add to your DCC power load if they draw track power.  So, battery-powered cars are no problem, but even LEDs draw a little bit.  Incandescent bulbs will draw considerably more.

It takes an iron man to play with a toy iron horse. 

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