I guess if you are running 10 or more locos at once, you might need a 5 amp booster. I am sure few of us, simultaneously run that many locos all at once. Club layouts and monster layouts with lots of regular visitors with cab controls might do that, but not even a major home layout would run 10 engines at once.
As far as idle is concerned, even with all loco's with sound, that is chicken feed. 10 operating Z or N gauge engines will not need much current at all, but 10 O of G gauge engines will need a heck of a lot of juice. Gauge does enter the picture
Most here are probably HO gaugers and if you have modern engines with modern motors, the current draw of a running loco with moderate to light load and sound is well under 3/4 amp. The little 3 amp block that comes with a digitrax Zephyr starter kit could run 4 HO trains easy. A single 5 amp booster would power far more trains than most any of us would ever run.
12 gauge buss (the only thing I use) is good for up to a 5 amp draw over 100 feet of 12 Ga. buss paralleled with code 83 N.S. rail and will only drop 0.75 volt at the farthest 50 foot distance from the booster or supply. With the little zephyr 3 amp block fully loaded at 100 feet of circuit (50 foot round trip) would only drop 0.45 volt! A true non-issue if there ever was one.
A little Zephyr DCC starter pak will run 3 modern train locos with sound, simultaneously, with no strain and virtually no loss over 100 feet of 12 gauge buss! No power districts and no boosters.
Note* If you use 14 gauge buss, the losses are virtually doubled! Result, If you want to stay away from buying boosters and creating power districts on a more normal sized layout, run 12 gauge buss. It leaves room for some growth and expansion without boosters.
Richard
If I can't fix it, I can fix it so it can't be fixed
Just to make it clear, the layout has 250'--maybe more -- of track but that includes sidings, both stub and parallel, a five track staging yard with each staging track about 10' long, and so forth. The bus is about 2X50 feet-- 50' for each bus wire.
I'll focus on getting everything off the 'tracks' and see how it all runs.
Thanks, guys.
Mike
If you have a lot of sound locos, you may be experiencing the problem with surge current that some sound locos have. Sound locos tend to have larger capacitors than no-sound ones. If they do not use a circuit to limit their crrent draw on power up, they can have large a curent draw as their capacitors charge up when power is applied.
250 feet of bus wire is a 500 foot wire length for the complete circuit. Even #12 wire will show a significant voltage drop over this distance. If it really 250 feet long? That's quite a layout. Even if you located the command station inthe middle, that's still 125 feet/250 round trip.
You may be at the point where you need more boosters, not because you need more amps, but because the physical size of the layotu is too big to not have voltage drop issues. 2 or 3 of the Tam Valley 3.5 amp boosters would be pretty economical. Just adding crcuit breakers will not solve the problem of long runs, so getting one big booster and some circuit breakers to keep 8+ amps away from the track won;t do it. Best practice would be to use the Prodigy output to feed the extra boosters and any stationary decoders, but not any track, and gap both rails between sections powered by each of the extra boosters. This way you gain the ability to not have a short in one section shut down the entire layout. 3 boosters spaced evenly along the 250 foot distance feeding equal distance in each direction(-----B----------B----------B-----) like that would result in about 84 feet of bus run (complete circuit), which is fine for #12 wire.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
How do you have the 250' wired? Bus with feeders?
First thing I would do is to remove everything from the track and then test the short recovery with the "quarter test" deliberately short the track at multiple different points and verify that it shuts down instantly and that it recovers properly.
If it does not, then the next step is to connect the system to a short section of track and verify proper performance when recovering from a short,
The key here is to see if the issue is the booster/command station or the wiring of the layout.
Simon Modelling CB&Q and Wabash See my slowly evolving layout on my picturetrail site http://www.picturetrail.com/simontrains and our videos at http://www.youtube.com/user/MrCrispybake?feature=mhum
Mike,
First thing I would do before reqiring is removing 10 of the locos and eyeing if the short recovery time goes down.
NP.
My situation is that I have a MRC Prodigy Wireless (3.5 amp capacity) and no booster on a layout with about 250 ft. of track. At the moment there are 18 decoder equipped locomotive on the layout, some at idle and others just sitting. When I have a short that trips the circuit breaker, it often takes a shut down and several minute wait to get power back on. Is this normal? Too many locos on the track?
I have a plan to move most engines into a block and shut it off to see how that affects operations. Any thoughts?
Decoders vary, of course, but a decoder that offers no sound capability will almost certainly draw no more than a decoder which is completely muted when both are idle. Add a light, or two, and the power draw goes up a wee bit. Add another loco, a bit more, and so on....
QSI's can be muted anywhere from no sound/fully silent all the way up to half of the maximum designed output if you haven't adjusted the master volume downward as part of your initial addressing and performance setup via the various CV's, as I do routinely. So, a QSI only muted to half full volume will draw more than almost any silent/muted other brand. Then, depending on the numbers not fully muted, and how much work the drives are performing, you can go all the way up to many amps.
I routinely silence decoders that I won't be using, and I routinely place my QSI's not being used, say in the roundhouse, on Stage III Coma, or into what they term full shutdown. Even in a deep coma, the decoder must, as Randy says, be paying attention, and there will be an invoice at the end of the year for that service...it isn't free in terms of power usage. But I also routinely have one or two other locomotives, often one steamer and one diesel, sitting in neutral and making the appropriate random sounds while I drive another train. I would guess the total consumption for a long coal drag with two steamers moving it up a grade, plus the two idling, to draw in the range of 2.5 amps....or less.
Crandell
Very little. Even motor decoders are running their CPU to listen for packets, but the overall draw is very little. Really not going to matter unless you have a LOT of locos. We regularly have over a dozen, most with sound, sitting in our engine terminal, plus that booster also powers the two mainline through tracks, which can both be occupied at the same time by a multiple unit consist going in each direction - never stresses a 5 amp booster, and it even resets fine if a short occurs. If our 'power mad' member is there with his locos - closer to 30 sitting there.
It depends, sound locos draw more than non-sound and some brands seem to draw more than others. My experience is with 10 locos, 7 with sound, my RRampmeter shows a draw of 1/4 to 1/3 amp when nothing is running on my NCE PH Pro system .
Hope that helps.
Does a decoder equipped loco draw a small amout of current if it is sitting on the layout but its address has not been called? I know some are programed to immediately make idling sounds when the command station is turned on. Anyone have an estimate of the current draw for a sound-on idling locomotive?