Ok so I have been searching the internet for the answer to this but to no avail. I am building my layout to be run by DCC (first time using DCC). I am going to break it up into power districts. I am trying to save money where I can and the NCE circuit breakers are $30 each. I know people use automotive lightbulbs to limit current in the event of a short which I know can still be dangerous and degrade dcc signal. Would it work to use automotive fuses instead of a dcc breaker or lightbulb? Thanks
Yes it would.
But when the fuse blows, you must replace it. When a circuit breaker blows, you usually just reset it.
Ed
You need fuses that are small, in the 3 amp range, less than the output capacity of your DCC system.
Eventually, you will tire of replacing fuses. It will be a while before the fuse cost overtakes the circuit breaker cost, but that will eventually happen.
My advice is to wire your power districts now, but just depend on the DCC system for one big block of circuit breaker protection. You can add breakers later.
So basically just let the internal breaker in my NCE be my only source of protection until I buy breakers you’re saying? Then just have the blocks wired up for when i do get breakers? I have a massive stockpile of fuses from when i worked as an auto electrician. Reason I want to at least run fuses is in case I step away for a sec and have a derailment I don’t want one of my N scale engines becoming toast.
The plastic twin bladed fuses are rated too high for what you need. The old time glass fuses can be found in sub 1.0 amp versions
I just watched a Youtube video, where the poster was breaking in a loco, left the room for an extended period of time. The loco derailed at the turnout and the Procab kept resetting resulting in melted ties and truck.
That’s the exact video that made me start looking into this. 1 or 2 amp blade fuses are too high?
The DCC Specialties PSX circuit breaker is 1.27 amps for the NCE power cab. My guess is that if it were set at 2 amps, the power cab would trip but the circuit breaker would not. But I am a guesser, not a guru. I’d wait for a second opinion if I were you. [:)]
The limiting factor is not the system’s capacity, say 5 amps, but the DECODERS’ capacity!!! They are more like 1.5 to 2 amps or so, and they’ll smoke in a really bad way if you use 3 amp bulbs or fuses to limit damage. Find out the maximum permitted current for all your various decoders, including those you may acquire and use in time, and then act to limit current damage accordingly.
If your controller’s ability to limit current is suspect or insufficient, and you want to be more careful with the decoders, then use fuses or tail light bulbs in series that do not exceed the upper limits for your decoders. But, if your wiring is good, your system should be able to manage shorts on its own.
The video is of an S5B booster. Does a Powercab automatically try to reset?
I don’t believe the powercab itself does but the booster does which i plan to get. So it sounds like 2a fuses are a possibility which I have many of but again I need to check all my decoders to be sure. Down the road I will probably try to get breakers but everything costs money and I can’t do it all at once.
I’m just curious, how many separate power districts (breakers) are anticipated? Sometimes individuals lean, especially initially, towards more than needed by including some extra ones that seem “useful”. That can depend on a number of things, like a club layout where segregated areas and multiple operators can be a nice optional feature.
But for a home layout, it can be as simple as one for mainline(s) and (typically) one per reversing loop. Sometimes folks think it is necessary or very useful, say, to have a connected yard on it’s own breaker to know where a problem has arisen. But if there is only one operator, my case, it’s usually obvious where a problem has occurred basis what is moving & where.
I only ask since the multiplier is a big factor in expense. Six means $180, not insignificant. Two is $60, etc. Just for consideration.
An aside, if reversing loops are involved, the reversers vary in type and cost. I went with $25 circuit breakers & $32 reversing breakers, finding I did not need fancier ones to combine with my NCE 5A Powerhouse Pro. I was a novice, but trusted the advice I got at Tony’s Trains, based on a discussion of my particular layout plan with my chosen DCC system.
https://tonystrains.com/product/dcc-specialties-onguard-og-cb-circuit-breaker
https://tonystrains.com/product/dcc-specialties-onguard-og-ar-auto-reverser-circuit-breaker
Hmm…well my plan has a 2 track main and a yard with reversing loop so I guess a minimum of 3 districts I would want without overdoing it. Layout is not very big 9.5x7’ but I want be able to run 2 trains and swit
For a PowerCab, and in N scale - I’d use 1 amp fuses for each section. If you have a good supply - and sockets for them so they just plug in, by all means, use fuses.
Also, even if just stepping out for a bathroom break, stop all moving trains. I never leave stuff running when I leave the room, for any purpose.
–Randy
Since you stated you are only using the PowerCab, not a booster as of yet, a circuit breaker is pretty much worthless. According to NCE, light bulbs protect the Powercab, circuit breakers protect boosters. Since the smallest circuit breaker that I know of is around 2 amps and the Power Cab only puts out 2 amps, the breaker will never reliably trip, even with a short, to protect the Powercab, which is why they build in protection to the Powercab. According to NCE, never use a breaker to protect the Powercab. For the Powercab, according to NCE, either the CP6 light bulbs or automobile light bulbs is the correct way to protect things.
Also remember, breakers don’t always trip at exactly the rated current, and the lower the rating, the less accurate the trip point actually is. A 2 amp breaker may trip at 1.5 amps or 2.5 amps, or even 3 amps, whereas a 5 amp breaker may trip between 4.5 and 5.5 amps. A 10 amp breaker may trip between 9.5 and 10.5, but this is far more than enough current to melt trucks and tracks, let alone decoders! The higher the amp rating, the smaller the tolerance spread.
I started my layout with a Powercab and the CP6 device, which is fed by the Powercab and distributes track power in six 1 amp legs. If you need more power than 1 amp, you can get a 1.75 amp bulb or parallel two 1 amp bulbs to get 2 amps, but mostly everything except large consists and a lot of lighted passenger cars should not need more than 1 amp, especially in N scale.
Now that my layout has grown and I have gone to boosters, I have a 5 amp circuit breaker on the output of each booster to protect my boosters from trying to put out more than 5 amps each, and the CP6 is still protecting my blocks of track.
I read on NCE’s web site that you should use either the CP6 or the circuit breaker, not both, but I called Ed Wilson at NCE to find out why and he had no good reason why you could not use the breaker and the CP6 in series, in fact, he th
You don’t know PSX and since NCE doesn’t sell it, they aren’t going to recommend it or mention it in their Zendesk info page.
To answer my own question, poking around the NCE Zendesk, the Powercab does reset itself, so in the youtube example of an unattended derailment, it would put out burps of 2 amps.
Thanks for the detailed info. This helps. The way I look at it is when I get around to getting a booster I will look into breakers also but good to know I don’t need them without the booster. I am still very new to DCC and have only been back in the hobby for a few months now. DCC itself was unaffordable when I left the hobby.
Good advice also Randy, thanks!
Hi Bigdaddy, I corrected my post to 2 amps apparently while you were writing your post. Meant to say 2, but typed 5, probably because we were talking 5 amp boosters.
I would think the automotive fuses would “work” but would be too slow. My club has used “bulbs” and we’ve never had DCC control problems because of the bulbs. BTW…How are you going to “split” the DCC signal from the command station into “power districts”?