Porkster Can anyone explain how the protection on the booster works. Does it trip out for a period of time then auto reset and if so what is the delay before resetting.
Can anyone explain how the protection on the booster works. Does it trip out for a period of time then auto reset and if so what is the delay before resetting.
Rich
Alton Junction
Porkster I will determine today whether it is the booster that is shutting down or the PSX circuit breaker.
An LED lights up on the PSX when it trips.
Henry
COB Potomac & Northern
Shenandoah Valley
Hi Randy, thanks for your continued interest. Yes, I believe that the gaps are good, I have used the black Hornby IRJ that seem to give a good sized gap, and no none have closed up. Both my loco's stopped. One is steam that appears to have pickups on all of the 6 big wheels(that's 3 per side) the other is diesel with pickups on both sides of the front set of wheels. The gaps are basically aligned. Cheers Porkster
Hi Rich, good call, its easy to get sidetracked when considering puzzling issues like this. Thanks to all for hanging in and trying to resolve the problem. I will determine today whether it is the booster that is shutting down or the PSX circuit breaker. Can anyone explain how the protection on the booster works. Does it trip out for a period of time then auto reset and if so what is the delay before resetting. It is my belief that it is the circuit breaker that is tripping and not the booster. I did the coin test yesterday and proved that each district is totally independent of the others. A short on one district has no effect on either of the other two districts. Which is what we would expect. What I will confirm today is, does a short on the RL trip the breaker or the booster. If it trips the breaker which is my belief, then I don't see too much of a problem. The breaker would be protecting the booster which is what we want. Should it prove that the booster is tripping, then yes we do have a problem. Hence my interest in knowing what a booster trip looks like. Porkster
What he's saying is that if one side of the gaps is powered with a PSX, and the other side via the PSX-AR, then when something bridges the gaps, if the polarity is right, the two protection devices are in parallel. But if it's not correct, it's a short circuit.
Now some additional questions - are the gaps definitely good? One hasn't closed up, has it? The locos that hesitate, do they have all wheel pickup, or are they split pickup, like a steam loco that picks up on one side with the drivers and the other side with the tender trucks? Are the gaps staggered or aligned across from one another?
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Porksterwhile the PSX and the PSX- AR are on different circuits, they are effectively in parallel both feeding power from the booster into the fault.
in parallel?
greg - Philadelphia & Reading / Reading
Whenever a thread about an "electrical" issue gets this long, and with this many replies, and the issue remains unresolved, I like to go back and read an OP's initial post.
Having done that here, and considering the replies that have followed, I am coming to the conclusion that there is a wiring problem on Porkster's layout. Let's review what we do know.
The Digitrax AR-1 didn't work correctly because of the presence of PSX circuit breakers which are solid state and react more quickly than the AR-1 with its mechanical relay.
When the AR-1 was replaced by the solid state PSX-AR, the pause when entering or exiting the reverse loop should have been eliminated by simply using the default trip current settings on all four PSX units. The fact that the pause was not eliminated at this point seems to indicate that the problem is with the wiring (assuming that the gaps are properly placed).
What that wiring problem is I cannot say at this point. Assuming that the wire gauge (bus and feeders) is large enough, it may be the way that the main bus and sub buses are wired. In my view, the use of terminal block(s) may be suspect - - not the use of terminal block(s), per se, but, rather, how the terminal block(s) are wired.
If the main bus is connected from the booster to a single terminal block and the four sub buses run from that terminal block to the input side of each PSX unit, then there should be no issue with the trip current set at default on each of the four PSX units. Perhaps a better way (or alternate way) to do this would be to feed the bus wires from the booster to the first PSX circuit breaker and then daisy chain to each subsequent PSX circuit and the PSX-AR.
If this were my issue, I would reset the trip current setting to default on each PSX unit, and do the quarter test in each power district to see what is going on. One thing that troubles me is that the high trip current setting on that one PSX circuit breaker is higher than the 5 amp booster, so it seems to me that if the booster would shut down the entire layout in the event of a short in that particular power district.
CV55 and CV65 are used on the PSX-AR for the so-called "double reverse mode".
Hi Randy, well said, thank you. i think it is important for us to realise that while the PSX and the PSX- AR are on different circuits, they are effectively in parallel both feeding power from the booster into the fault. They both recognise it which is why we need discrimination between them in order for the AR to do its thing before the PSX trips. I agree it is a timing issue rather than a current issue. I may be wrong, but I don't believe that I have any wiring problems. The bus feeding the track is 11 gauge, the feed to the PSX and PSX-3 is 13 gauge. I have 24 gauge droppers on every piece of track but not the points. The bus feeding the reverse section is 18 gauge with 3 droppers of 24 gauge wire. All joints are soldered. So the question begs why am I having this problem, fault currents are likely to be high with minimum impedance given the size of cable I have used. I noticed on another site of someone with a discrimination problem with a new PSX they had installed. NCE told him to set CV55=1 and to make an adjustment to CV65? There is no reference to these CV's in the manual apart from them not being used. Interesting I thought. Cheers Porkster
OK, we are all saying the same thing. You ONLY want wires from the power source to ONE breaker, and from there to the rails, not to another breaker or reverse unit (except in the case of the AR-1, which is a reverser only and not a breaker)
When all devices are PSX or PSX-AR, there should never be a situation in which the inputs of one come from the outputs of another, all inputs should be sourced right to the booster. We're all on the same page then.
There are two factors involved - the trip current, and the trip speed. For a true short, with adequate wiring - one breaker set at 5 amps will trip just as well as one set to 1 amp, assuming the reaction time of both is the same. However you cna get less than a solid short if the wiring is inadequate, or if whatever is shorting the rails is not making solid conact (effectively, a poor connection, with measurable resistance across that point). In that case, a 5 amp breaker may not trip, but the 1 amp one would. Now if both breakers are set on the same trip current, but one is configured to react in 1/100th of a second and the other is set for 1/10th of a second, the first one will trip first. This is what happens when a PSX is feeding an AR-1, the PSX 'sees' the short faster than the AR-1 can correct it, and thus cuts all power and now the AR-1 cannot do its job. If someone made an AR-1 that used a solid state relay instead of an electromechanical one, you'd still have the same problem, although operation may be flakey rather than fail every time, with 2 fast acting devices it's a race condition to see which one trips first. Thus the PSX-AR was designed to be both a breaker and auto reverse, so there is no reason to connect it after any other circuit breakers and risk creating a race condition which would make operation unreliable at best. It internally handles the issue of what trips first by always first trying the polarity reversal, and only if that fails to clear the short does it cut off power completely.
You'd think after 40 years of typing I would be better at it - I started typing work for school long before most kids, because you should see my handwriting... Spelling things I'm good at, and I rarely make those kinds of grammatical errors you see all over the place these days, particularly from younger generations, the ones that make you just cringe. I can't play any musical instruments, either - I have very poor coordination between my brain and fingers.
Yeah, however you say it, one thing is clear. Since the PSX-AR is both an auto-reverser and a circuit breaker, it needs to protect the reversing section on its own.
Since Porkster experienced a pause as his loco crossed the gap into the reversing section, a short was detected but the polarities were not immediately flipped. So, some other device detected the short and cut power. The question is why and what device cut power -- the PSX or the booster?
not sure this is being clearly said -- if there are two circuit breakers in series, they will likely operate independently as soon as their trip current is exceeded.
current rises abruptly when there is a short. A circuit breaker with trip current of 1A isn't going to prevent one with a trip current of 2A from triggering. A short across a device that can supply 5A will result in a 5A short, triggering both breakers.
I have no experience with this, but it seems best to only have only one device that takes some action when there is a short. And I'm suggesting that it may not make sense to have a separate circuit breaker in series with an auto-reverser that is only an auto-reverser. This is different than an auto-reverser with a circuit breaker function.
rrinker Rich - it won;t matter where you put them on a bus coming from the booster, electrically it's all the same. If I run a pair of wires from the booster, and tap off for various circuit breakers and reversers, it's not going to matter which one is 'first' - they are all wired in parallel. As long as each device had a direct link (ie not going to the outputs of any other device) back to the booster's output, all is good. Or are you trying to say something else that I'm not quite catching? I do agree that setting the trip current to the max is not a solution. That may erroneously allow the AR-1 to work, but the 15.6 amp trip level exceeds botht he booster AND the AR-1 capacity which is why it even has a chance to work. You certainly should not have to do that with a PSX-AR for the reverser. Needing to do so indicates there is another wiring fault somewhere, perhaps a crossed feeder os simply insufficient feeders or a too long/small bus which would make the short of crossing the loop gaps looks like a high current load rather than a short. --Randy
Rich - it won;t matter where you put them on a bus coming from the booster, electrically it's all the same. If I run a pair of wires from the booster, and tap off for various circuit breakers and reversers, it's not going to matter which one is 'first' - they are all wired in parallel. As long as each device had a direct link (ie not going to the outputs of any other device) back to the booster's output, all is good. Or are you trying to say something else that I'm not quite catching?
I do agree that setting the trip current to the max is not a solution. That may erroneously allow the AR-1 to work, but the 15.6 amp trip level exceeds botht he booster AND the AR-1 capacity which is why it even has a chance to work. You certainly should not have to do that with a PSX-AR for the reverser. Needing to do so indicates there is another wiring fault somewhere, perhaps a crossed feeder os simply insufficient feeders or a too long/small bus which would make the short of crossing the loop gaps looks like a high current load rather than a short.
I agree with you as to the wiring from the booster to the various PSX units. The reason that I make reference to upstream and downstream (these terms were stated to me on the NCE-DCC forum) is that the PSX-AR cannot be "protected" by a separate PSX circuit breaker. Maybe a better way to put it is that the PSX-AR cannot be nested inside of a PSX-protected power district. When terminal blocks are involved, I have seen situations where the pause occurs, and the terminal block wiring needed to be re-routed.
In Porkster's situation, he mentioned that when he installed the new PSX-AR on his layout, presumably with default current settings, locos still paused as they crossed the RL gaps. That should not happen at default settings. There should be no need to reduce the current setting to 1 amp on the PSX-AR, while raising the current setting to something greater than 5 amps on the PSX circuit breaker. So, for that reason, something else must be wrong.
Eich - it won;t matter where you put them on a bus coming fromt he booster, electricallt it's all the same. If I run a pair of wires fromt he booster, and tap off for various circuit breakers and reversers, it's not going to matter which one is 'first' - they are all wired in parallel. As long as each device had a direct link (ie not going to the outputs of any other device) back to the booster's output, all is good. Or are you trying to say something else that I'm not quite catching? The "upstream/downstream" terminology generally means the order in which the outputs of one device connect to the inputs of another - if the outputs of a PSX feed the inputs of a PSX-AR, then the PSX-AR is 'downstream' of the PSX and that would be incorrect. You would normally use a terminal strip of some sort but let's say I cram 5 pairs of wires into the booster track terminals, and connect a pair of wires each to 3x PSX's and 2x PSX-AR. They are downstream from the booster, but none of them is upstream or downstream of each other and this would be correct. In your picture of the pair of wires coming out and going to the PSX with the PSX-AR tapping off in the middle - if the PSX and PSX-AR were swapped, that's still electrically the same, further out on a bus line is not really 'downstream' - electricity travels too fast for that to have an effect over a few 10's of feet. Another example, instead of DCC, assume plain steady DC power (like you'd apply to the rails for some of these direct radio systems). I say DC so there's no fallback to the "well it changes direction" idea. Puit the power supply in the middle of a bus that extends 20 feet to either side. When you switch on the power, both sides get power at the same time, there's no waiting for the electricty to 'fill up' one side then go to the other.
I do agree that setting the trip current ot the meax is not a solution. That may erroneously allow the AR-1 to work, but the 15.6 amp trip level exceeds botht he booster AND the AR-1 capacity which is why it even has a chance to work. You certainly should not have to do that with a PSX-AR for the reverser. Needing to do so indicates there is another wiring fault somewhere, perhaps a crossed feeder os simply insufficient feeders or a too long/small bus which would make the short of crossing the loop gaps looks like a high current load rather than a short.
Dunno about the speed of electrons. An electrical engineer, I am not. But, regarding the placement of one or more PSX-AR's on the same booster as one or more PSX circuit breakers, some time ago, I was told by some very knowledgeable guys on the NCE-DCC (Yahoo Groups) forum, that the PSX-AR(s) must be wired upstream of the PSX(s), and the PSX-AR manual confirms that. Where do you read instructions for the PSX-AR showing it downstream of the PSX?
Some time back, we also had two different forum members (not Brendan) with the same issue as Porkster. Again, the experts on the NCE-DCC forum pointed out that the use of terminal blocks can cause this pausing issue, depending upon how the terminal blocks are wired relative to the various PSX units.
The biggest problem with combining PSX-ARs with PSX circuit breakers on the same booster is current detection. The PSX-AR manual mentions this with the following comment. "If you are using both Power Shield X Breakers and Reversers on a layout, and the locomotives hesitate when crossing a reverse gap, then increase the Trip Current on the Power Shield Breakers to the next level or until the PSX-AR operates correctly". Porkster did this, but incorrectly in my view, by setting the trip current too high on the PSX unit.
I'm glad there is a diagram. I was asking if the optional circuit breaker (PSX) was in place or not. My issue with downstream is that electricity moves at the speed of heat (also light), in lab conditions 1 foot in 0.001 milliseconds.
In the real world we have various size wires, solder joints and bits and pieces in the PSX itself slowing things down, but still, electrons must be moving PDQ which minimizes the downstream effect.
Why do the instructions for the PSX-AR show it downstream of the PSX?
Porkster, diregard that diagram in the PSX-AR manual that illustrates two reverse loops, one at each end of the mainline. It is proper to use both of the output ports on each PSX.
Thinking on that a little more, having both feeds (dcc 1 and dcc 2 ) through the PSX circuit breaker possibly explains why I have to have CV49 set so high. I was surprised to find that putting a volt meter across the tracks did not give me the true track voltage? I had to take the back off the command station and get track voltage off the cct board as per the procab manual. I will rewire tomorrow and test it out.
Porkster Well that's interesting, I must admit I had not noticed that subtlety. So in the case of mainline section B, in effect, dcc 1 from the booster goes through the PSX circuit breaker then on to the track while dcc 2 from the booster goes directly to the track. I wonder why that is?
Well that's interesting, I must admit I had not noticed that subtlety. So in the case of mainline section B, in effect, dcc 1 from the booster goes through the PSX circuit breaker then on to the track while dcc 2 from the booster goes directly to the track. I wonder why that is?
Porkster Hi Rich, sorry to be a little slow, but I take that when you talk of the "other side" your are referring to the track side of the command station as opposed to the power input side from the power supply. So by me connecting the PSX-AR directly to the track supply I am effectively connecting directly to the booster?
Hi Rich, sorry to be a little slow, but I take that when you talk of the "other side" your are referring to the track side of the command station as opposed to the power input side from the power supply. So by me connecting the PSX-AR directly to the track supply I am effectively connecting directly to the booster?
Two of the ports connect to the 5 amp power supply, and the other two ports provide power output to the track.
Just to clarify something based upon your first question, the "power input side from the power supply" is feeding into the booster, and the track power is provided by the output side of the booster. The "other side" of the command station is the control bus/cab bus side.
Porkster With respect to the wiring, I have taken a 2.5mm + and -ve supply from the Power Pro track output to a terminal strip under my layout. I then loop off with separate supplies to the PSX-3 unit and the PSX- AR. The PSX-AR is not feed through the circuit breaker. I have assumed and maybe incorrectly that because the two other districts feed from the two other circuit breakers in my PSX-3 are insulated via IRJ they have no bearing on the district with the RL. I have therefore NOT altered CV49 on the other two breakers, they will still be on their default setting of 0 which is the same as 3. Have I gone wrong here? Do I need to change CV49 on the other circuit breakers setting all 3 CV49's to 3 or 4?
With respect to the wiring, I have taken a 2.5mm + and -ve supply from the Power Pro track output to a terminal strip under my layout. I then loop off with separate supplies to the PSX-3 unit and the PSX- AR. The PSX-AR is not feed through the circuit breaker. I have assumed and maybe incorrectly that because the two other districts feed from the two other circuit breakers in my PSX-3 are insulated via IRJ they have no bearing on the district with the RL. I have therefore NOT altered CV49 on the other two breakers, they will still be on their default setting of 0 which is the same as 3. Have I gone wrong here? Do I need to change CV49 on the other circuit breakers setting all 3 CV49's to 3 or 4?
On the wiring protocol, the terminal strip under the layout could be an issue. Even though the PSX-AR is not fed through a PSX circuit breaker, if all four PSX units are receiving power simultaneously through the terminal block, the PSX-AR is not literally wired "upstream" of the PSX-3. I have seen that exact situation cause a pause, as you experienced, on more than one layout of fellow forum members.
The solution is to feed the PSX-AR directly from the booster so that only the PSX-3 draws power from the terminal block.
Porkster Hi Rich, thank you for your help. Please let me clarify my control set up. I purchased my PH pro system from DCC Concepts who recommended a "cobalt PSU2+ 18v 5A" power supply. i think this unit is only protected by a glass type fuse cartridge judging by the fuse holder on the front of the unit. So I don't have a " booster" as such, and my power supply will only trip if the fuse blows.
Hi Rich, thank you for your help. Please let me clarify my control set up. I purchased my PH pro system from DCC Concepts who recommended a "cobalt PSU2+ 18v 5A" power supply. i think this unit is only protected by a glass type fuse cartridge judging by the fuse holder on the front of the unit. So I don't have a " booster" as such, and my power supply will only trip if the fuse blows.
You do have a booster. It is the other side of the DCC command station.
So, when you are connecting the PSX-AR to the command station, you are connecting it to the booster side of the command station.
rrinker The thing is, with the PSX line, there's no reason to have a PSX-AR in line, upstream OR downstream of a PSX-x. The PSX-AR is both an auto-reverser and a circuit breaker, so if flipping the polarity fails to cure the short condition, it cuts all power. The PSX-AR should be fed directly from the booster, just like any PSX-x's.
The thing is, with the PSX line, there's no reason to have a PSX-AR in line, upstream OR downstream of a PSX-x. The PSX-AR is both an auto-reverser and a circuit breaker, so if flipping the polarity fails to cure the short condition, it cuts all power. The PSX-AR should be fed directly from the booster, just like any PSX-x's.
Hi Randy, thank you for your comments. Yes, the PSX-AR is feed directly from the power pro command station which in turn is fed from the 5amp power supply. The AR1 is not compatible with the PSX-3 so on advice from Digimax I fed the AR1 directly from the Power Pro command station. Cheers Porkster
Sorry Henry, I don,t quite follow, but yes the entrance track is PSX-3 protected. This is the breaker that has ended up with a CV49 setting of 12 or 13 to get the RL to work. Cheers Porkster
Hi Rich, thank you for your help. Please let me clarify my control set up. I purchased my PH pro system from DCC Concepts who recommended a "cobalt PSU2+ 18v 5A" power supply. i think this unit is only protected by a glass type fuse cartridge judging by the fuse holder on the front of the unit. So I don't have a " booster" as such, and my power supply will only trip if the fuse blows.(Which has not happened - yet!) With respect to the wiring, I have taken a 2.5mm + and -ve supply from the Power Pro track output to a terminal strip under my layout. I then loop off with separate supplies to the PSX-3 unit and the PSX- AR. The PSX-AR is not feed through the circuit breaker. I have assumed and maybe incorrectly that because the two other districts feed from the two other circuit breakers in my PSX-3 are insulated via IRJ they have no bearing on the district with the RL. I have therefore NOT altered CV49 on the other two breakers, they will still be on their default setting of 0 which is the same as 3. Have I gone wrong here? Do I need to change CV49 on the other circuit breakers setting all 3 CV49's to 3 or 4? Cheers Porkster
The AR-1 is ONLY an auto-reverser, so if the problem is a short and not just a polarity mismatch, it will just flip back and forth and never cut power to the track. For short protection as well as reversing, thge AR-1 has to be downstream of a circuit breaker. It works with the PM-42 because all of the Digitrax devices had a trip speed setting - with an AR-1 downstream, the PM-42 has to be set at the 'fast' setting, not 'fastest' or the same thing that happens with the PSX will happen - the PM42 will trip before the AR-1 can reverse the phase.