Thanks everyone, so it looks like I need the PSX then to ensure no current will go to the loco during a derailment. After reading the above looks like the CP6 will still allow 1A at 12V to the locomotive which could still cause the tiny Z trucks to melt, right? I thought CP6 were simply made up of 1A fuses.
In general, the tungsten light bulb has fairly low resistance so you won't really notice. However, this depends on Loco motor current (and passenger car incandescent bulbs). So if you ran AZL locos, you'd never know it, even several of them. But, run with a märklin or especially an MTL locos with permanent magnet brush motors, you would probably would notice it, a bit. It's not a 'linear' function. But still, if you have a short, its generally a wheel on a loco, and it will be passing ~1 to 2 Amps so still a chance of overheating. It just doesn't have the effective power of 12 Volt too.
I use a 12 V lamp in series with my track. Have done that for years, and it works well with all my AZL DCC engines. On my new layout I have divided it into 2 powersections, each with a lightbulb in series. Then if one section is short, I can still run on the other. I also use a 12 Volt powersupply to power the engines using my NCE PowerCab. Check up my setup: http://www.platelayer.com/---platelayers-dcc.aspx
Yup, thanks got it! 1A is 1A no matter what voltage. Good to know about the bulbs. I plan on running some older marklin, some that exhibited HOS too so their amp draw is higher than usual. I will opt for the PSX.
Not so fast! The PSX is ABSOLUTELY the fastest breaker, by far (Default is 1ms (1/1000 of a second), if it exceeds the Trip Current of 1.27 Amps (after you have jumper 1- of J6 or set CV49=0 ). However, the PSX still Resets every 2 seconds, so still "Watch Your Trains. In our experience (mostly N, that 1ms trip is WAY too fast, especially with steam locos, between Booster sections (where the voltage can never be exact, sound cars, bad brushes on commutator motors, etc. So you will likely have to change CV55 from 0 to a 1 to enable 'delay'. CV65 controls this with a programmed value 8x your desired time. The Default is 24 which is 3ms (24/8=3) which still will be too fast. You'll probably be at 80=10ms. So if you find unexpected stalls/hic-ups while running, its Tripping. Either wire a remote 12V DC LED or board-mount a 'Sonolert' on the board so you know whats going on. They are the Best but really designed for Sound boards, locos with 'Keep Alive' backup power or lighted cars with anti-flicker. The NCE EB1 is also very fast and works perfect for us. There are 7 of them on the layout and we have run mega modules at the NTS shows. The CP6 or just a bulb works too.
So I ended up getting a 12V 1A wall wart to power the NCE power cab. And since I don't have a big layout I just ended it at that. First thing I noticed was considerable drop in speed of the locomotives from the original 13.8V power supply. But I rarely run at full speed anyway so not an issue. Eventually I ended up shorting the unit when a locomotive ran right over a (Rokuhan) turnout. I pulled off the locomotive the minute I saw it, and it wasn't warm at all. All trucks looked good. The power cab display went blank which I never saw before. A simple replug in of the power supply and off and running as usual. Anyways seems like I am content with the smaller power supply and "watching your trains" approach.
Could you give me a link or specs to the wall wart? I want to be sure to get the right plug for my PowerCab. Also, I have my PSX-1 set up so that when it trips the track power a buzzer sounds, then after clearing the short, I have to press a reset button to restore power. So auto reset VS manual reset is a user selectable feature. The buzzer and button are DCC Specialties add on products for the PSX-1.
This is what I bought and it fit. The top speeds lower a bit but I don’t need to go past 20 anyway. https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/113192623513
If you use a supply less than ~2 to 2.5 Amps, you Power Cab will NOT be the component that 'protects' ! The wall-wart will current limit FIRST as it rated at 1 Amp. So every time you get a 'tick' short, your Power Cab will loose power and take several seconds to reboot !!! Then, you can once again start up your loco ! (over and over). Protect at the load BUT . . . IMHO: The Power Cab will be JUST FINE as it is. The only time you need protection (long time potential short) is "if" you derail a loco on a turnout. Your odds are REALLY low that you will have an issue. Now, go run your trains (and let me know in a *many* months later about your first issue and don't fib about 'not watching your trains'
Are only locos in motion the counting factor for the needed amps? What about the the others, idling on the track ( in my case arround 40 locos)? And what about the switch decoders? I guess, in DCC all decoders are permanentely under current. I´m planning to use a big Digitrax booster with (selected ) 3 amps for my layout. Is that okay? Thanks for any comments! TexRail
You can use a 5A DCC system, 3A is fine too. Most Z decoders allow no more that 20ma per LED, so if you have 40 locos all with lights on, thats less than 1A, and running locos pulling a train might use 50-80ma per loco, unles it's Marklin or MTL F7, using no more than 200ma each. Add up everything and most likely a 3A system is more than enough. When you get into a lot of Tortoise turnouts with stationary decoders, those will add up too.
Yup, you gotta add it up, see the NCE website also for explanations, specifically about how many trains can be run, but they say to add it up. I am an avid model airplane flyer and we are mostly concerned with motive power but lots of us have an amp meter in our flight tool box. It just plugs into the supply and shows data drawn from the battery, change to a different propellor, for instance, and confirm your electronic throttle (ESC) can handle the new amp draw before flight. I imagine something like that is available for our train use as well? I mention it because while rule of thumb amp draws will average out I know my Marklin loco's (not DCC) vary greatly in power requirements.
