Hi all, I have just created my first DCC-EX with a mega, standard motor shield. Is a circuit breaker required to protect the the trains on the layout and the DCC-EX command station in the case of a short circuit on the track? I know a local model train dealer has an NCE EB1 Circuit Breaker available. In the past I depended on the Power Cab doing it.
on mine i experience shorts all the time (because i forget to throw "switch" / "turnout") and my dccex system shuts down for a bit and as soon as i fix the short its right back up to speed as it was........But i too have this same question and never really got an answer ...... MY thought was that if there was a short protection of some sort it would prevent the system from shutting down at the base station.....
DCC-EX has the short protection built into the Command Station's software/hardware and operates as Sid mentioned. No need to have an additional circuit breaker if you can live with a couple things. As Sid mentioned if you have other things on the DCC buss that you don't want to shut down if there is a track short you need to go further. Also until recently the command station cut the power at about 1.8-2 amps. So if you run enough engines and/or other items on the buss you need to go further. They did develop a motor shield that will put out up to 5 amps. I think they sold-out but I'm sure they are probably getting more in. Personally I'm not a big fan of 5 amps on an N scale layout. 5 amps can still do damage. The solution to both isn't just a circuit breaker. At least not a great solution as it isn't going to solve much. If you have a circuit breaker after the command station if will cut power off like the command station does now. I guess you could split the power after the command station and put the circuit breaker on the track power feed and it would cut that feed only if there was a short on the track. The feed to accessories from the command station that doesn't go to a circuit breaker would protect the accessory feed if there was a short there. The other option and what I'm doing for multiple power districts is have one or more boosters and possible additional circuit breakers. I'm using Tam Valley boosters and circuit breakers on a DCC-EX command station. Power comes from the command station (CS) to a booster and in my case I have two circuit breakers on a booster. The booster is powered by an inexpensive power supply and can put out 5 amp intermittent, 3 amp continuous, and I think it breaks at about 1 microsecond. It has a jumper if you want to power an accessory feed where it will power them for I think 5 minutes if the CS goes down. So one could connect the booster to the CS and run it to the accessories and the CS would handle the track. The booster would also act as the circuit breaker for the accessories. In my case I'm connecting two circuit breakers to a booster and the output from each goes to a different section of track. If either section shorts it shuts down and the other sections and the CS stay up and everything on them continues to run. You can also set their circuit breakers to trip at 2 amps or 4 amps. I have mine set to trip at 2 amps. Other manufactures have similar components but check to see what they are. The items aren't all that expensive. What one would pay to replace one burned out loco would easily pay for a booster and depending on what you spent on the loco maybe a booster plus one or two circuit breakers. In summary my DCC-EX command station now is only making and sending the DCC instructions on the DCC buss not supplying any current and shouldn't shut down for any reason. Sumner
sumner so if i read this right..... if i install a booster between the cs and the track the booster will shut down and the cs stay up and running.. As my system is right now its CS to track and when i get a short the CS shuts down until i clear the short. (kinda drives me nuts really as it also shuts down the pi4 but powers right back up just as it was before the short when i clear the short )
Bottom line for your Question is no you do not need a circuit breaker as the CS will shut down untill you remove the short...
Thank you sydney and sumner, I feel I can do a test run on my layout. As I committed to the circuit breaker I will still get it as it can be used to isolate a power district.
Depending on the manufacture you could add either a booster or a circuit breaker. Since I know Tam Valley products I'll use them as an example. You will need to research other manufactures. A circuit breaker would be the least expensive way to go with Tam Valley at about $34. Run from the command station to it with the two wires and from it to the track with two wires. A short on the track and track power would be cut but CS would keep running Disadvantage would be power to the layout would still be whatever power is to the command station. I believe using the booster like you suggested is the better option. Run from the CS to the Booster and then to the track. The booster runs about $48 and you would need a $12 to $15 power-supply if you don't have one (I bet you do). The power-supply could be whatever voltage you wanted (I run 12v). To start maybe only use the booster with the CS. It will break the power but the CS won't go down. Also you will now have more power to the track than you do now. Down the road if you want more power districts to make it easier to find a short add multiple circuit breakers to the the single booster. You would also have the option to add more boosters if the layout warrants that. Sumner
Thank You Sumner i will get me one of them boosters and give it a whirl. if nothing else i will have some extra parts for future layout.. side note the dccex cs and throttles are working fantastic. love the whole setup...
