I am using a Digitrax Super Chief 5 amp booster/command station on my layout. I have uaed 14 gauge wire for the power bus and 20 gauge for the feeders. What I am seeing, or rather hearing, is that in sections of the RR the booster doesn't shut down when a short occurs. Rather I will hear a high pitched whine from the place where the short is occurring and it seems to happen in places furthest away from the booster/command station. i do have the 'scale switch' set for HO. Is it time to add another booster? Other than that, everything is running normally.
There's never time to do it right, but always time to do it over.....
You may not need a booster. What you may be hearing is the ARC caused by the short circuit. What you should do is divide your layout into several districts with an adjustable circuit breaker like the PSX series with one for each district. There are times when the short circuit will not trip the command stations circuit breaker because the short does not draw enough current to trip it, but the heat generated at the short location will cause some damage. Break up the power buss into two or three seperate districts and set the circuit protection to a lower trip current.
I agree with the previous reply.
How big is your layout?
A 5 amp booster is a lot of power, so it takes quite a bit to require a second booster.
If your current booster isn't tripping, you need to look closer at the number of feeders. You probably need more feeders.
Do the quarter test along your layout at various points to be certain that the booster is tripping in all cases.
Rich
Alton Junction
retsignalmtrWhat you should do is divide your layout into several districts with an adjustable circuit breaker like the PSX series with one for each district
I could easily set up two districts since where this conditon occurs is inside of a large return loop which was added last year. I will admit I am little bit of a novice so could you offer a little explanation to your comment - or maybe point me in some direction.
Thanks - I am sure this is the solutiion.
Harold, is that "large return loop" a reverse loop?
richhotrain I agree with the previous reply. How big is your layout? A 5 amp booster is a lot of power, so it takes quite a bit to require a second booster. If your current booster isn't tripping, you need to look closer at the number of feeders. You probably need more feeders. Do the quarter test along your layout at various points to be certain that the booster is tripping in all cases. Rich
Rich,
This occurs inside of the reverse loop section which also contains a small yard. I am running additonal feeders today as I am doing other wiring in a different place in the layout.
I also thought the installation of the AR1 might be a culprit. The unit won't accept 14 gauge wire. So I ran 22 gauge into it from one bus, ran 22 gauge out to a new 14 gauge bus which powers the loop. I was never happy with that arrangement.
Size of the layout - it's about 252 square feet.
richhotrain Harold, is that "large return loop" a reverse loop? Rich
Yes, it is a reverse loop wired into an AR1. Without measuring, it's about 25-30 feet long.
Harold, one more preliminary question.
Are the shorts only occurring in the reversing section (loop), or does this short circuit problem without tripping the booster occur in other parts of the layout as well?
I might add that the size (gauge) of your bus and feeder wires is adequate, in my experience.
richhotrain Harold, one more preliminary question. Are the shorts only occurring in the reversing section (loop), or does this short circuit problem without tripping the booster occur in other parts of the layout as well? I might add that the size (gauge) of your bus and feeder wires is adequate, in my experience. Rich
Interesting question. I just went down and tried the quarter test. The booster trips everywhere else except in all the track contained in the loop. When I do the test within the loop, the AR1 clicks rapidly as if it is trying to trip and I hear the whine at the point of the test. Maybe I need to adjust the trip current???? Also interesting, I just installed a separate reverse loop closer to the booster than the other one and it does the same thing - AR1 'clicking' and whining.
I can still set up power districts but need a little guidance......
The first thing that I would do is to adjust the trip current on the TTC screw on each AR1. Each one-quarter turn of the screw increases (or decreases) the amperage sensitivity.
If the quarter test throughout the layout, outside of the reversing section(s) trips the booster, then you need to increase the sensitivity of each AR-1. Trial and error with the turn of the screw will get it right - - - - unless the AR1 is faulty.
HaroldA I can still set up power districts but need a little guidance......
I have a double main line measuring 162 linear feet around the layout. My DCC had been controlled by an NCE PH-Pro 5 amp booster with 5 AR1's controlling five different reversing sections.
I decided to divide my layout into 4 power districts by adding a series of four PSX circuit breakers. I ran into all kinds of problems in that the mechanical relays on the AR-1s didn't act as quickly as the solid state PSX units. I wound up replacing all 5 AR1s with PSX-ARs, a costly undertaking.
Because of the configuration of the PSX/PSX-AR units, I wound up adding a second booster. Ugh.
So, look before you leap.
Ready?
It's working fine. The AR1 is "intercepting" the short, which is what an auto-reverse unit does. The booster (or base station) should not trip under these conditions. Only the reverse loop shuts down, because that's the only part of the layout which sees a short.
You should, however, do something about feeding the AR1 with larger wires. If nothing else, solder a very short length of narrow wire to your standard bus wires so the thin-wire run is minimized.
It takes an iron man to play with a toy iron horse.
Thanks guys - will try what you have suggested. Looks like I have a little work today - adding more feeders, adjusting trip currents and fixing the wires going to the AR1. It's going to be hot today so a good day to spend in the cool basement.
MisterBeasley Ready? It's working fine. The AR1 is "intercepting" the short, which is what an auto-reverse unit does.
It's working fine. The AR1 is "intercepting" the short, which is what an auto-reverse unit does.
I am not so sure about that. Harold says that he hears the relay on the AR1 clicking repeatedly and he hears a whining sound which tells me that the short is pesisting. The AR1 should click once and only once.
Either the TTC adjustment is insufficient or the relay is sticking. It is not fine.
richhotrain MisterBeasley Ready? It's working fine. The AR1 is "intercepting" the short, which is what an auto-reverse unit does. I am not so sure about that. Harold says that he hears the relay on the AR1 clicking repeatedly and he hears a whining sound which tells me that the short is pesisting. The AR1 should click once and only once. Either the TTC adjustment is insufficient or the relay is sticking. It is not fine. Rich
The AR1 is a relatively new unit. Once I get back down there i will try adjusting the trip current aling with a couple other ideas from you guys. Believe me when I say I am a novice when it comes to RR electronics so anything to keep it simple is fine with me. As a side note, i do wish i could find a comprehensive book on he topic.
Adjusted properly, the AR-1 should click once when the rails are shorted and if the short persists after the relay clicks, the booster should shut down.
It's OK to run smaller wire to the AR-1 terminals, but it should be kept short, a few inches to give enough room to connect it to the full-size bus. Voltage drop in the wire is proportional to botht he size of the wire and length, so short lengths of smaller wire will not cause enough drop to be a problem, unless everything else is marginal to begin with. You should be able to fit at least #18 wire in the screw terminals of the AR-1.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
It would have been nice if you mentioned the reverse loops in your original posting. The AR1 operates by detecting a short circuit condition when a loco enters the reverse loop and it flips the polarity of the loop to correct that condition. Either the AR1's sensitivity is too low or it is detecting a short in the reverse loop that it cannot correct. Make sure you have all the insulated joiners or gaps in their correct places and try readjusting the trip sensitivity. The PSX AR's are a better choice but they are a little more costly.
I was an avid user of AR1s for years. But they are, admittedly, out of date technology with the mechanical relay.
I have no regrets with the switchover to the solid state technology of the PSX-AR along with the PSX circuit breakers.
First of all, thanks guys for your help. I did go down and adjust the trip current on one of the AR1's and it works perfectly. The one which controls the reverse loop I was referring to is also fine. i am almost ashamed to admit, but when I crawled under the layout to add more feeders I said 'what was I thinking when I wired this????' The feeders are way too long, there aren't nearly enough of them and the bus is way too short which probably accounts for the feeders being too long. SO, tomorrow there is a trip to Lowe's in my future along with a significant re-wiring project in this one area. Going forward I will also look into the PSX devices as the Digitrax devices are probably updated. Thanks for that tip.
Like I said, there's never time to do it right, but there's always time to do it over. (sigh)
Harold, glad to hear that the TTC adjustment worked. As long as it is working properly, there is no need to move to PSX-AR solid state technology at this time. I might suggest that the same applies to adding circuit breakers or a second booster at this time.
Chances are, if you create power districts and use solid state technology for the circuit breakers, you are going to have to replace the AR1s as well. That gets expensive, so hold off until you absolutely need to go in that direction.
But definitely get those bus wires and feeder wires in order.
There is one huge advantage relay devices like the AR1 and PM42 have over the others (besdes that the PM42 can report state to Loconet) - thsoe relays have effectively NO voltage drop. Even the best MOSFETS like used on the PSX4 and PSX-AR (assuming they DO use the best) do not have a zero resitence when 'on' and those cause a little voltage drop. If you build your own computers at all, you may have seen motherboards advertised as using "Low RDS MOSFETS" - This is the resistence, drain to source (don;t worry, you don;t have to undertsand all that) - basically, this is the resistence you will measure between the terminals that the power flows through. It's never 0. It can;t be zero (unless someone invents the ideal semiconductor). Just like long runs of bus wire, or on a larger scale, the resistor in series with your LED headlighs, the more resistence, the larger the voltage drop (also proportional to current). Relays don't have this problem.
As far as reversers (and frog power, for that matter), I will have PLENTY of "old fashioned" relays on my layout - to set frog polarity and also automatically flip reverse loops when the turnouts change position. Rather than wait for a short and then fix it, my plan is to avoid shorts altogether. Sure it's a bit more complex than hooking up 1 wire from a Frog Juicer to the frog, but a short is a fault. The idea is to avoid faults.
rrinker As far as reversers (and frog power, for that matter), I will have PLENTY of "old fashioned" relays on my layout - to set frog polarity and also automatically flip reverse loops when the turnouts change position. Rather than wait for a short and then fix it, my plan is to avoid shorts altogether. Sure it's a bit more complex than hooking up 1 wire from a Frog Juicer to the frog, but a short is a fault. The idea is to avoid faults. --Randy
Randy,
My sentiments exactly. Like I have said before....''I avoid them, like the plague''.
Take Care!
Frank
zstripe rrinker As far as reversers (and frog power, for that matter), I will have PLENTY of "old fashioned" relays on my layout - to set frog polarity and also automatically flip reverse loops when the turnouts change position. Rather than wait for a short and then fix it, my plan is to avoid shorts altogether. Sure it's a bit more complex than hooking up 1 wire from a Frog Juicer to the frog, but a short is a fault. The idea is to avoid faults. --Randy Randy, My sentiments exactly. Like I have said before....''I avoid them, like the plague''. Frank
Reverse loops or reversers?
I suspect that you are referring to reverse loops. But, at least some of us have one or more reverse loops on our layouts including the OP who has two reverse loops. I have 5 reversing sections on my layout. Nothing wrong with reverse loops, certainly not the equivalent of the plague.
As far as reversers like the AR1 and the PSX-AR are concerned, they don't work on DC layouts anyhow, so they only matter to DCC users in the first place. The AR1 works just fine in the right environment, and Harold nicely solved his problem with a simple turn of the TTC adjustment screw. Once you start to add some solid state electronics like a PSX circuit breaker to your layout, however, only then does the AR1 show its age.
As far as powering the frog, you can get by quite nicely with an unpowered frog in most cases. I do. I have over 60 turnouts on my layout, and none of the frogs are powered. No problemo!
No, avoid auto-reversers. Since with DCC you can change the phase under the moving train at any time, you can use a relay to change it when you line the switch, BEFORE the train hits the gaps. This applies to any loop that is at least as long as the train that will be running over it - line switch, train enters, any time after the last car clears the switch but before the loco hits the switch, you line it the other way, and this also flips the loop track phase. No short ever occurs. Works for a wye as well. ANd yes, even a turntable - that fancy NYRS PTC III turntable controller has an option to drive a relay to reverse the bridge polarity when it turns more than 180 degrees. So you get instant flip instead of the dead zone of split rail, so sound doesn't cut off, and there's no short to be corrected by an autoreverser.
Yes, it's slightly more complicated to set up (depending on things such as what sort of switch machines you use - the servo drivers I use already HAVE a connection to drive a relay, and there are others that even shut off frog power while the servo is moving and then applies correct polarity only after it reaches the end of throw, so you don't have to worry about "DCC friendly"), but there is never any chance of hesitation and no issues with high inrush reset.
rrinker Since with DCC you can change the phase under the moving train at any time, you can use a relay to change it when you line the switch, BEFORE the train hits the gaps.
Since with DCC you can change the phase under the moving train at any time, you can use a relay to change it when you line the switch, BEFORE the train hits the gaps.
rrinker No, avoid auto-reversers.
No, avoid auto-reversers.
richhotrain rrinker Since with DCC you can change the phase under the moving train at any time, you can use a relay to change it when you line the switch, BEFORE the train hits the gaps. What type of relay are you referring to, Randy? Rich
What type of relay are you referring to, Randy?
You can use a DPDT relay (your choice of coil voltage) and cross wire like a reversing DPDT toggle switch!
I used a DPDT toggle sw for a few years on my current layout to control the polarity of my huge Reverse loop staging until I rebuilt the layout to use a differeny type of staging tracks.
I had the toggle sw at the end of the Reverse Loop and would have the Toggle handle set that it would point into the Loop or out of the Loop when flipped to show direction of the Train and thus track polarity!
Each time a train went into the Reverse Loop staging I would just flip the toggle to set the polarity for the next train coming out of the Reverse Loop Staging!
I could have easily replaced the Toggle Sw with a Relay and using a Caboose Ground Throw w/Electrical Contacts - to auto throw the Track Polarity.
One doesn't have to have the ELECTRONIC Auto Throw Auto Reversers as good old Mechanical Relays lasted for years in the good old days!
BOB H - Clarion, PA
Bob, thanks for that reply.
I wondered if Randy was referring to a DPDT. I have used that approach in the past to manually switch my reversing section(s) before moving to an auto-reverser mechanism.
I appreciate your making that distinction between a manual DPDT toggle switch and an automated DPDT relay.
Richhotrain,
Seeing You are determined to find fault with my replys...Bob H and Randy, gave You my answer.
I also have over 60 turnouts on my layout, original Shinohara and Atlas and they all perform quite well, Thank You, along with 3cab DC control.
A couple of additional comments from the OP - First, I realized I needed another way to turn trains and the solution was a second reverse loop. I finished it up yesterday and it going to add so much to the ability to run trains and to keep my interest. In addition, it is going to finally allow me to create a little place called Elmer's Crossing in memory of my dad.
Second comment is this - I remember, and not too fondly, the days of an Altas Controller that only worked when I was very profane, or of the days of block wiring when it seemed as if I was forever throwing toggle switches. if I read the posts correctly, maybe components like the Digitrax AR1 have been the next step in the evolution of reverse loop controls and the new all electronic components are the next generation.
For me, it was once again a matter of cost and then simply not having the knowledge to do it any other way. When someone starts talking about PSX's and MOSFETS, my eyes just glaze over because I don't have the understanding. As I said in an earlier post, I wish there was a print resource for guys like me who aren't familiar with the intricacies of electronics - one that started with the basics and went from there. I have found places on the internet but even some of those assume too much.