Hi,
I have an N scale layout that's about 4' x 9'. I have a main line that can go into a small switching yard that includes a turntable. I think I can divide my layout into 3 sub districts. What type/name of circuit breaker do you suggest I use?
Thanks,
Andy
I like the PowerShield circuit breakers from Tony's Trains - easy to set up and they come in various configurations. You can look at them www.tonystrains.com
Yep, I've used the tail lights for years on my large HO Siskiyou Line layout and they work great. They're a lot cheaper than the Power Shields ... $1-$2 per block.
Joe Fugate Modeling the 1980s SP Siskiyou Line in southern Oregon
It takes an iron man to play with a toy iron horse.
MisterBeasley wrote:Is it that important to subdivide your layout? For a large layout, dividing it into separate sections to help with fault isolation is a good idea. It's also helpful if you're running multi-operator sessions, so that some trains can keep running when one section shorts out. However, for a small, single-operator layout, the effort to do this may be more than it's worth.
True enough.
But for debugging purposes, it always helps to divide things up, even on a smaller layout. The first time you get a mystery short, you'll be happy you subdivided the layout!
Hm.
Im on the fence here... What do I do with the ABBA F units that might hit a short? There is potential for damage.
I see a bulb on a track feeder wire located between the power BUS and the Rails. Do I need one bulb or two? Mind you there is like potentially 8 amps availible at the DCS 200 station.
Should every track feeder get a bulb?
Or should I just get the power shield and hope they throw quickly enough to save the engines?
The Preview video on the Website was very well done, particularly the diagram presented.
Falls Valley RR wrote: Hm.Im on the fence here... What do I do with the ABBA F units that might hit a short? There is potential for damage.I see a bulb on a track feeder wire located between the power BUS and the Rails. Do I need one bulb or two? Mind you there is like potentially 8 amps availible at the DCS 200 station.Should every track feeder get a bulb?Or should I just get the power shield and hope they throw quickly enough to save the engines?
You need to divide your layout up into train-length blocks, and then put a bulb in series to the feeders going to one of the rails in that block. The current potential of your booster (8 amps in your case) doesn't have anything to do with what gets to the track through the bulb -- the bulb will limit the current to the block.
For example, if you put a single 1156 bulb on the feeders to the rails on the fireman's side of the train block, no more than 2.1 amps will flow to the block when a short occurs. Two amps is the typical max value of an ordinary power pack and will seldom do any damage when a short occurs.
As the video link threads show, you can adjust the amps flowing to the track by using different combinations of bulbs. I don't recommend anything over about 3 amps to the track or damage to your track or equipment may result.
Using the bulbs limits the current to the track, and thereby limits the damage from a short.
An ABBA loco set probably draws about 1 amp normally, or perhaps near 2 amps if the units are all sound equipped. With the bulbs, you need to allow some "headroom" on the current limiting capacity, or the bulbs will start drawing power and taking it away from the locos.
Generally, you should run the bulbs at about 70% capacity in a train block. If your ABBA loco set has all-sound powered units (and no dummies), then it will draw near 2 amps. The 1156 bulb is rated at 2.1 amps, and doesn't have sufficient extra capacity for this load. This means the bulb will begin to glow a dull orange and the locos will slow down, unable to reach top speed because the bulb is limiting the power the locos are getting.
If your loco set draws near 2 amps, then you need a bulb combination that limits the current in a single train block to around 2.85 amps so the bulbs are at 70% capacity. Two 1142 auto tail light bulbs wired in parallel and then put on the feeders to one side of the rails in a train block will be about right, resulting in a train block current limit of 3 amps.
The loco set will draw the 2 amps without the bulbs interferring, but if there's ever a short, the current won't exceed 3 amps -- which is way better than an unprotected 8 amps flowing through the short. A current of 8 amps will be enough to weld wheels to the track or to heat up and melt plastic truck sideframes.
(8 amps at 14 volts (most DCC systems output 14-16 volts) is 112 watts. Just imagine applying a 112 watt resistance soldering tip to the short and turning it on. In a matter of seconds, the area will be hot enough to melt solder, so you can just imagine what kind of damage might result ...)
jfugate wrote:But for debugging purposes, it always helps to divide things up, even on a smaller layout. The first time you get a mystery short, you'll be happy you subdivided the layout!
That is one of the basic tenets of any electrical system. Take Joe's advice, you'll be glad you did.
Karl
The mind is like a parachute. It works better when it's open. www.stremy.net
I am in the process of building a new layout using an NCE Power cab, 1.7 Amp DCC system. I am uncertain on what lamp or combination of lamps to use.
To protect the 1.7 Amp Power cab, and my 2 expensive new QSI sound locos, what lamp combination should I use? Single 1156 limits to 2.1 amps which is more than my Power cab can offer, so would the lamp do its job?ORSingle 1142 bulb, limits to 1.5 amps. Is this to low, limiting my ability to run locos?OR Some other combination of lamps, resistors, etc?
Thanks