rrinker Depends on how much marketing had to do with the design. Really. If the compnents are just squaking by in terms of current capacity and so forth, keeping a short in place and walking away for an hour to eat dinner is probably a bad idea.
I disagree that marketing has anything to do with this issue. Leaving a short in place, or ignoring it, is a different story. Especially if the breaker is set to continually reset each time a short occurs.
That is why at the club we have the breakers set to trip and remain tripped until manually reset. We had too many occurrences where some idiot would not pay attention to what they were doing and either forget to turn the throttle down all the way and the train would creep until it created a short, or think they'd stopped the train when it had actually stopped due to short.
Marketing has EVERYTHING to do with engineering design. If engineers just built what they wanted, with no control by marketing, products would cost a lot more than they do, but they'd also seldom fail. Why pay extra for a 50% safety margin when 5% "ought to be enough"?
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Well, another lengthy explanation eaten by the network monster. I should just wait until I get home, never happens there.
So if district A has a short and breaker A trips, but there is one feeder from district B crossed over and connected to the bus for district A, there may not be enough current flow to cause breaker B to also trip - so now youhave power flowing into the output of breaker A. Some MOSFETs can handle that, it's al alternative to using a diode for reverse polarity protection on DC circuits. May not have damaged that, but what about the detection circuit, the part that monitors current flow and decides there is a short and triggers the MOSFET. Who knows how the EB-1 works, there's no schematic. The PSX line seems to have a large transformer - if that is what is used for current sense then the current sense should be isolated from the control circuit via the transformer and they should be hard to kill. Other breakers though have no isolation between the detection circuit and the track power, so spikes or power applied to the outputs can certainly damage parts.
rrinker So if district A has a short and breaker A trips, but there is one feeder from district B crossed over and connected to the bus for district A, there may not be enough current flow to cause breaker B to also trip - so now youhave power flowing into the output of breaker A. Some MOSFETs can handle that, it's al alternative to using a diode for reverse polarity protection on DC circuits. May not have damaged that, but what about the detection circuit, the part that monitors current flow and decides there is a short and triggers the MOSFET. Who knows how the EB-1 works, there's no schematic. The PSX line seems to have a large transformer - if that is what is used for current sense then the current sense should be isolated from the control circuit via the transformer and they should be hard to kill. Other breakers though have no isolation between the detection circuit and the track power, so spikes or power applied to the outputs can certainly damage parts. --Randy
Any idea how many amps are generated during the quarter test?
Here's another question. Can the use of 12 gauge bus wire and one pair of crossed feeders contribute to potential circuit breaker damage in the event of a short? In other words, is the bus wire gauge too large for a relatively small HO scale layout, especially when detecting shorts?
Rich
Alton Junction
Get some clip leads for your multimeter (because holding the probes to a piece of rail is a pain - and not as solid a connection as a soldered feeder. Clip it to the rails. Set in ohms mode. Drop a quarter on the section of track, see what the resistence is. E=IR so I=E/R, E is you DCC voltage, R is the resistence you just measured.
If it's too low to read on common meters, one of my fancier ones might work. Since you aren't supposed to press on the quarter, I doubt it can be 0 ohms. Which would be infinite current, aka, as much as the source can provide.
With proper wiring (big enough bus for the length, enough feeders), it's going to be enough current to trip at least a 5 amp booster. Maybe not a 10 amp, but you shouldn't be applying a 10 amp booster directly to the track unless you're running lots of heavy O scale locos. The problem comes in when the combined resistence of the quarter and the wiring is such that the current is just under the trip threshold for the circuit breaker or the booster - that's when you get lots of heat and things melt. 15V at 4.5 amps is 67.5 watts - my soldering station is only 60 watts. But you should be able to draw 4.5 amps from a 5 amp booster all day long without anything cutting out - it's rated to supply 5. 2.5 amps on a breaker at 15 volts is a little more sane, 37.5 watts. but even something as small as a 15 watt light bulb can melt plastic, as evidenced by the awesome Casio scientific calculator I used all through college only to have melted when my toddler son "hide" it by putting it in a bedside lamp. By the time I realized it was in there (after turning the light on) it was already too late and the flap, which also had keys, was melted beyond repair.
That's why you should never walk away from a short, either fix it, or just shut everything off when you leave the train room (my preference). ANd I am leaning strongly towards using manual resets on breakers, so it doesn;t sit there and keep trying every few seconds. One short, circuit opens, that's it. No retries, no chance of generating significant heat. A loud buzzer ala one of John Allen's 'trick' cars would draw attention to the area of the operator who goofed up, too. (ok mostly kidding about the buzzer, that would just be annoying - but most of the breakers have options for external manual reset buttons and status LEDs)
rrinker but even something as small as a 15 watt light bulb can melt plastic
but even something as small as a 15 watt light bulb can melt plastic
Nuts, I once foolishly replaced a 1.5 volt incandescent bulb with a 12 volt incandescent bulb in the plastic headlight housing on a Proto Heritage Berkshire. Completely melted the headlight shroud and part of the rest of the housing in a mere few seconds.
Randy, then I have a question, and a pretty basic one at that. I have two PSX's and I have never had a short except for the ones I induced to check the wiring and the circuit boards before I installed them. They are installed under my layout and when I power up my layout I check to see that the LEDs are on.
Now, say there is a short, I would have to get under the layout to check to see if the PSX has tripped. In that case I would shut down the system and then search for the short. The whole process from the short to shutting down the layout can take a few seconds. Are you saying that those few seconds may be too many?
Bear "It's all about having fun."
It's generally pretty obvious when you have a short - everything in a particular section of the layout stops. If it's something more than that, the whole layout would stop. The breaker keeps the power off, but tries periodically to see if the short still exists. A few minutes of those blips isn't going to hurt anything, but leaving it cooking for an hour might.
Why don't you connect your good circut breaker to the power leads from the booster to the track so you can run your trains. At least you will have protection until you hear from NCE.
SouthPenn Why don't you connect your good circut breaker to the power leads from the booster to the track so you can run your trains. At least you will have protection until you hear from NCE.
Well I am running trains. The main is connected to teh breaker and the yards to the booster.
Gary
Were these dead circuit breakers in use when you had the DC track feeders hooked up to layout accessory lighting?
http://cs.trains.com/mrr/f/744/p/264162/2982049.aspx?page=2
Henry
COB Potomac & Northern
Shenandoah Valley
Hi all,
Still haven’t heard from NCE but thanks to Rich my new PSX breakers are installed and all functioning properly.
NO Bus or Feeder wiring has been changed Since we already confirmed the original wiring was good.
This morning we connected all three PSX breakers to the booster by providing booster power to the left most breaker and then daisychained the other two.
One by one we individually tested each breaker And the corresponding district. Each breaker tripped and the booster stayed on.
Then we added a second district and confirmed each breaker just tripped the corresponding district. That worked so we added the third.
All three breakers connected, all three tripping only the shorted district and the booster stays on unaffected.
Thanks Rich for taking the time to help.
Now I’m really curious as to what happened to the NCE EB1’s. When NCE gets back to me I’ll post what they tell me.
Received a call from NCE today.
NCE diagnosed the problem! EB1’s are all good!
As it turns out the EB1’s were programmed to detect a higher voltage than what the jumper setting indicated and to wait longer than normal before tripping.
Apparently, as long as the programming jumper is in place and you select a CV while programming a locomotive you are programming the EB1’s also.
When I first received and installed the EB1’s about two years ago I had just changed my DC Layout to DCC and knew as much about DCC Systems and programming as I do about string theory. I installed the EB1’s and tested each district and everything worked fine. It wasn’t until quite some time later I decided to try to program a DCC locomotive. They were too LOUD so I lowered the value in CV130 to 65. There was no reason to retest the breakers and there were no shorts.
A while later when i did begin to read about programming accessories I came across the EB1 programming capability But did not venture there. I assumed (you know what they say about that) unless I called up the EB1 address [2044] (Like you need to select a loco) I was only programming the selected loco. Therefore I left the program jumper on.
CV130 is the master volume on my BLI Locos but CV130 also controls EB1 settings. so every time I programmed CV130 I was unknowingly programming the EB1’s. There are other EB1 CV’s that were messed up too. They are now back to factory default.
The tech told me that they now tell everyone to program the EB1’s for manual reset. He programmed the three i sent. So to use them I will need a momentary On/Off switch connected to jumpers 1 & 2.
I’ll put them in storage with these notes. The PBX breakers are working just fine.
gdelmoro I was only programming the selected loco. Therefore I left the program jumper on. CV130 is the master volume on my BLI Locos but CV130 also controls EB1 settings. so every time I programmed CV130 I was unknowingly programming the EB1’s. There are other EB1 CV’s that were messed up too. They are now back to factory default. The tech told me that they now tell everyone to program the EB1’s for manual reset.
Just to be clear, the momentary pushbutton is there to manually reset the breaker after a trip. That has nothing to do with the programming. If you don't read the instructions and remember to remove the programming jumper as it states, you will have the same issue.
Yes - got it Maxman.
Think I’ll sell them on eBay.
I sort of recall we mentioned trying to reset the EB-1s in case some CV got set incorrectly...
But, all's well that ends well.
gdelmoro when i did begin to read about programming accessories I came across the EB1 programming capability But did not venture there. I assumed (you know what they say about that) unless I called up the EB1 address [2044] (Like you need to select a loco) I was only programming the selected loco. Therefore I left the program jumper on.
29 posts into the first thread, someone wrote
The EB1 is programmable by CV's I don't know how hard it is to inadvertently change those settings.
Not hard would be the answer.
I was expecting the answer to be, "they are fried we don't know why" so we all learned something.
Randy you are correct!
Due to my DCC naivety and belief that there was no way it could be an EB1 programming issue And not knowing what I know now, these were the facts to me:
1. I never even tried to program any of the EB1’s so how could there be a programming issue. I didn’t even know how.
2. To program anything on a DCC system (as far as I knew) you had to call up the loco address (or in this case the accessory address), then select a CV and then enter a Value. I knew I never even attempted to do that related to the EB1’s.
3. Finally in my rookie DCC state I couldn’t imagine how all three EB1’s could have had the same programming problem when I knew I never programmed even 1.
CLEARLY, all 3 were invalid.
What I learned thanks to all the people that helped and special thanks to Rich and Randy; When you ask for help on this forum and knowledgeable people offer assistance you should at least give it a try And a whole lot about DCC Circuit Breakers.
Well, Gary, the Case of the Missing Electrons has been solved. And, while you had to spend some serious coin that you did not have to spend, as it turns out, it sounds like NCE has learned something when it comes to telling their EB1 customers about programming the EB1. I for one have learned a lot as a result of your dilemma.
gdelmoroNCE diagnosed the problem! EB1’s are all good! Embarrassed As it turns out the EB1’s were programmed to detect a higher voltage than what the jumper setting indicated and to wait longer than normal before tripping.
First off, thanks Rich for guiding me to this 'continuation thread'. I was really interested in finding out why these EB1 failed,..of course now we know they did not fail.
But this 'fault' of theirs does not make me too inclined to use them on my new layout. I think I will go with the PSX's
Brian
My Layout Plan
Interesting new Plan Consideration
Brian, I agree. The PSX and PSX-AR units are superior in every respect.
This is my latest dilemma, and the reason I became aware of these different time delays in shutting down.About a year ago I purchased 4 auto reversers knowing I would need a few. The ones I bought were these, DT300, PSX-AR Breakers.
I went back into my email history and found this quote by the gentleman I purchased them from,..
They are combo reversers and breakers, yes. The ones I have are slightly older, and do not have the config for the delay. You can use them alone without the standard non-reversers for the rest of the layout, which is what we've been doing; but we now want to add the non-reversing ones for all the power districts to protect everything else. And the problem with the reversing ones that I have, is that without the config for the delay, they will get into a "race state" with each other to assert dominance when used for adjoining blocks, and we don't want that.
They are combo reversers and breakers, yes.
Does this mean I might run into problems with using these reversers with those PSX circuit breakers?........OR, can I set the timing on the PSX breakers so as not to conflict with the non-programable PSX reversers I purchased.
...follow on question about
Do I suppose it is not always necessary to utilize both items in one power district?? For instance I am proposing to wire all of my staging tracks into one PSX reverser,...and that reverser has a circuit breaker.
So my question is do I technically need the addition of a PSX power sheld circuit breaker for the staging deck power district?
I fail to see how this experience would say not to use the EB-1. It's less expensive and has 99% of the features of the PSX. It works exactly like the PSX - the PSX is not "superior in every way"/ An EB-1 is electronic, just like the PSX (and I still dispute the whole concept of no relays being superior to everything, as I have never had a problem with my PM-42 and sound locos - LOTS of sound locos in the same section - it still reset, no inrush problems. But a PM-42 is not very useful for a non-Digitrax system).
The EB-1 has all the important features of the PSX - electronic operation, optional manual reset button, remote LED indicator option, configurable trip current, configurable response time, and even more - for special cases, which I doubt applies to 99.99% of people, the EB-1 was a fairly complex programmanble retry time sequence that can be set via CVs.
About the only thing the EB-1 does not do is come in a panel of 4 boards together. Singles only. 4 of them are still cheaper than a single PSX-4.
What's odd is that NCE's answer to the PSX-AR is actually more expensive - so for an AR, the PSX-AR would seem to be the choice.
BTW the PSX is ALSO programmable via accessory programming on the main - so the same accidently programming could be done to a PSX if the default address isn't changed, just like happened to the EB-1.
As for the question of an additional circuit breaker, no, the PSX-AR is also a circuit breaker, if the short isn't fixed by flipping the output phase, it cuts off power like a plain breaker. So there is no need to put any additional breakers in line with the PSX-AR.
rrinker As for the question of an additional circuit breaker, no, the PSX-AR is also a circuit breaker, if the short isn't fixed by flipping the output phase, it cuts off power like a plain breaker. So there is no need to put any additional breakers in line with the PSX-AR. --Randy
My attraction to the PSX units is what I perceive to be a unit that is a little more fool-proof from electrically-challenged people like me. I just want as fool-proof of an item that I can get, without being a programing knowledgeable person.
I know many folks get all excited about this programing aspects, but at this DCC entry point I am at, it is not to appealing to me. And its pretty easy for an unintiated person like myself to get lost in some of the sutles of the wording, and the text, and the compatibilities.So with my limited grasp of the subjects I have another question about that staging yard power district I am asking about. I will have 18 tracks of staging in 3 groups of 6 tracks each,...all fed by the 3-way turnout. I am proposing that all of this staging will be its own power district. And I imaging having a single electrical switch that can turn the power off to the entire district until I am ready to extract a train from there,... (that will shut down those DCC/sound trains from drawing any current while not being used). When I flip that switch on to get ready to select a train, there will be some sort of 'in-rush' current,...I read this about the circuit PSX breaker...
The PSX series is a product of Larry Maier's 10 years experience in designing and producing intelligent, solid state, DCC circuit breakers and auto reversers. The PSX specifically addresses the increased inrush loads (currents) which occur due to large capacitors used for sound systems. This load appears as a system short circuit until the capacitors are charged. The logic in the PSXs determines if the load is a true short or just an inrush overload.
My question is will those older PSX reversers I have already be able to handle this situation?...or is this a reason I might what to have BOTH the reversers that I have PLUS the newer circuit breaker boards??
The PSX-AR is for reverse loops, not for an ordinary power district. You need a regular PSX for that. That the PSX-AR is a reverser AND a circuit breaker was so you didn;t have to buy and wire in two devices to both automatically reverse the polarity on the loop under normal operation AND protect against something like a derailment int he middle of the loop. Some other autoreversers are just that - autoreversers. If there is an actual continuous short, they don't cut piower. They need a regular breaker upstream. The PSX-AR does both in one unit.
The issue witht he older ones is mainly recovery under ehavy inrush currents - lots of sound locos, or putting keep alives in everything. It's funny that they had to redesignt he PSX to manage the inrush from sound locos while I've never had an issue with any of my Digitrax stuff handling multiple sound locos (and peopel ahve said they couldn't get their PM-42 to reset with just ONE sound loco - I'm sorry, that's not the PM42, that's inadequate wiring). At any rate, the current production ones do test for inrush and manage it. As do the EB-1.
They both come out of the box ready to use, you don;t HAVE to program anything. The PSX series has a lot of programmable options as well.
Your existing PSX-AR will probably have no issue with the reverse loop function. If there is a short that shuts down the entire stanging area, if you have a lot of sound locos, it may not restart until you remove some. The new ones would definitely be fine.
For the rest of the layout, either a new PSX or EB-1 for each power district will handle any sort of loco.