I was on a layout tour yesterday and the owner was having a problem with his layout. Everytime he has a short the whole layout drops. This problem surficed when he added in a Ramp Meter throught which the power is routed to the layout. The path is as follows Command station--->Ramp Meter --->PSX-4, PSX-2, PSX-2 wired in parallel--->Power to each block in series. Blocks are isolated from each other as far as I can tell. There are no jumpers installed on the PSXs (mechanically set to 2.8A). CV 49 is set to the minimum breaker trip value ~1.8A. The Command station is a 5.0A Power pro. Its setpoint is 5.1A per the manual and is not adjustable. The command station is in fact tripping before the PSXs verified by the flashing fault light when dead short is applied.
Other Data:
The owner says that it was working correctly before the Ramp Meter was installed.
Same thing happens when Ramp Meter is taken out of the circuit.
All 8 PSX breakers have melted shrink wrap on their transformers.
I personally hand over handed the wire from the command station to the breakers, there is no bypass around the breakers. Is it possible that all 8 of the PSX's failed at the same time when the Ramp Meter was installed?
Thanks
You need to determine if the fault lies with the layout or the PSX breakers.
Remove the PSX breaker outputs at all of them. (You should have used a terminal block at the outputs for troubleshooting). Then power up the system and short each PSX output one at a time.
The command station booster should not shut down. If it does, try resetting the PSX braeker settings. They can be set to 4 amps each, since the command station booseter puts out 5 amps and should short out only when 5 amps is reached. If that doesn't help, it may be possible that the breaker in the command station booster has failed and is shutting down with a small current, so you need to check for that.
If everything acts OK when the breaker outputs are shorted, there is a problem in the layout wiring somewhere. I would look for the sub-power dirstricts to be tied together somewhere. Look in the area where work was done last.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
I have that exact setup, a PH-Pro 5 amp command station/booster, a RRampMeter, and several PSX circuit breakers, all wired just as you described it.
I don't see how the installation of the RRampMeter between the booster and the circuit breakers could adversely affect the breakers.
Has the layout owner reset the PSX circuit breakers?
He didn't adjust CV49 while there were Trip Current jumpers on J6, did he?
Elmer's diagnostic techniques are excellent advice at this point.
Rich
Alton Junction
richhotrainI don't see how the installation of the RRampMeter between the booster and the circuit breakers could adversely affect the breakers.
Yeah I couldnt figure that one out either. Is it possible the breakers in the PSXs have a different trip timing than the Command station? Is that adjustable?
The Command station is a bit on the old side, and it was used for several years as the only means of overcurrent/short circuit protection. It says PH-1 in the bottom corner and Northcoast Engineering is spelled out. Have no Idea how old the system is or if he ever updated it (apparently they send you a new chip in the mail when an update comes out).
richhotrainHe didn't adjust CV49 while there were Trip Current jumpers on J6, did he?
There were no jumpers installed, nor did it appear that any were ever installed.
I tried shorting the output of the PSX's, it still dropped the whole layout. We did not however disconnect the outputs of the breaker from the layout. (this should have been in my initial post)
CV 49 is set to the lowest trip value of approximately 1.8A, for all of the CBs.
The update chips from NCE for the command station were issued for improved throttle control, but there was nothing on the update chips that would affect the booster one way or another.
I don't believe that the PSX units take too long to trip, causing the booster to trip first. In my experience, the PSX trips immediately with its solid state circuitry. In fact, the PSX trips so fast that I had to replace my Digitrax AR-1 units with PSX-AR boards. The mechanical relay on the AR-1 was too slow for the PSX, so the PSX tripped first.
The only thing that I can imagine in your case is that the trip current on the PSX is set too high so the booster trips first. But you are indicating that the trip current is set lower than 5 amps on the PSX.
What size is the wiring on the bus, and between the booster, the RRampMeter and the PSX units? Is it all the same gauge?
From what you are indicating, all was fine until the RRampMeter was installed. As Elmer indicated, it may be best to start over. Temporarily remove the RRampMeter and all but one PSX. Reset the PSX and then do the quarter test on the power district controlled by that PSX. The PSX should trip, not the booster.
Then proceed from there.
The wiring appears to be all the same gauge. The layout is the disassembled and reassembled in new location York Haven layout featured in one of the MRs from 1990. All new wiring was installed and it appears to be either 12-16 guage, not sure which, because I didnt install it.
Well, that's good. You really do want all of that wire to be the same gauge.
Your friend needs to go back and start over.
Take out the RRampMeter and PSX units and then add back one PSX at a time, resetting and testing each PSX as you go.
Installation of the RRAmpmeter should have had no effect on the PSX or system, so I see no need to remove it.
cacole Installation of the RRAmpmeter should have had no effect on the PSX or system, so I see no need to remove it.
Yet, the problem supposedly first arose when he installed the RRampMeter.
So, it makes sense to remove it while he re-installs and resets the various PSX units to get them back to proper working order.
Then re-install the RRampMeter.
What else can he do at this point?
Believe OP stated the owner said the "same thing" happens when the ramp meter is removed. If that is true the problem lies elswhere and may or may not have been caused by the initial installation of the meter. Will be interesting to see how this turns out. Not being an electronic expert, I'll watch with interest.
The minimum current that the PSX breakers can be set for is 1.27 amps. The default current level is 3.81 amps without using jumpers and CV 49 set to 0. Possibly the trip current is improperly set and is higher than the command stations trip current. Use the jumpers to set the current level and see if the problem persists. Setting CV49 to 0 should be done before using the jumpers.
BMMECNYC All 8 PSX breakers have melted shrink wrap on their transformers.
Melted shrink wrap as in overheated?
Are the transformers on all 8 PSX boards visibly damaged?
Over heated? What current were the units set for? Setting CV49 to 15 provides a 19.1 amp current level.
retsignalmtr Over heated? What current were the units set for? Setting CV49 to 15 provides a 19.1 amp current level.
I was asking what he meant by "melted shrink wrap" on the transformers on all 8 PSX units.
It is not clear whether or not the PSX units have been damaged.
The PSX board do NOT have shrink wrap on their transformers, unless you're referring to the light tan colored insulation that is wrapped around their windings.
If there is some other type of shrink wrap around the transformers that appears to have been melted, the owner must have added it for some inexplicable reason, and may possibly have inadvertently applied 110 Volt AC or similar high voltage to them.
cacole BMMECNYC All 8 PSX breakers have melted shrink wrap on their transformers. The PSX board do NOT have shrink wrap on their transformers, unless you're referring to the light tan colored insulation that is wrapped around their windings. If there is some other type of shrink wrap around the transformers that appears to have been melted, the owner may possibly have inadvertently applied 110 Volt AC or similar high voltage to them.
If there is some other type of shrink wrap around the transformers that appears to have been melted, the owner may possibly have inadvertently applied 110 Volt AC or similar high voltage to them.
richhotrain cacole BMMECNYC All 8 PSX breakers have melted shrink wrap on their transformers. The PSX board do NOT have shrink wrap on their transformers, unless you're referring to the light tan colored insulation that is wrapped around their windings. If there is some other type of shrink wrap around the transformers that appears to have been melted, the owner may possibly have inadvertently applied 110 Volt AC or similar high voltage to them. That's what he must be referring to, and so the question is, has that insulation melted somehow? Rich
That's what he must be referring to, and so the question is, has that insulation melted somehow?
Im guessing its insulation, not shink wrap. It looks as if it was at one time white but now the edges around the hole are a tan color with coils of the transformer clearly visible. The remainder of the insulation is white. I would say that it is melted.
So have you done any testing yet with the outputs disconnected from the PSX's? If so, what are the results? If not, why not? The problem is not going to fix itself.
I don't think that there will ever be an answer to this problem posted on the forum, because the OP was on a layout tour and the owner of one of the layouts expressed the problem.
Too bad, I would like to know what caused the problem and how it will be eventually resolved.
Always do the quarter test to make sure SOMETHING cuts off the power in the event of a short? Insufficient feeders or anything that allows less than 5 amps to flow would not trip the booster, so you could have 4.999999 amps at fuill track voltage flowing through a short - nearly 60 watts at 15V to the rails.
However - the PSX breakers are rated to handle - hmm, the documentation doesn;t state a limit, though the max trip current is 19 amps and there is a note not to exceed 10.2 amps continuously unless you add heat sinks to the transistors - at any rate, if you can run it that high, then the insualtion on the transformer should not melt at those levels. And with only 5 amps available at the source, it's impossible to put 19 amps through the PSX. Accidently fed power int he wrong way? If anything, this would damage the transistors, not the current sense transformer. Transformers don't care which way the current flows - other parts might.
All a mystery.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Based on richotrain's comment, I think this discussion has reached a dead end.
Yeah, I think it has reached a dead end.
As Randy says, it is all a mystery.
Think about it.
The layout owner had 8 PSX units daisy chained together connected to a 5 amp booster. Everything worked great.
Then, one day, he inserts a RRampMeter in line between the booster and the PSX units.
Poof ! He fries all 8 PSX units.
Something doesn't add up here.
I had the NMRA division webmaster FWD a link to this forum thread to the layout owner. We meet every other month so I will let you know in December about what happens. Thanks for the responses. Its about an hour or longer drive for me to the layout owner's house, so I will probably not be going there to help out personally.
rrinker Always do the quarter test to make sure SOMETHING cuts off the power in the event of a short? Insufficient feeders or anything that allows less than 5 amps to flow would not trip the booster, so you could have 4.999999 amps at fuill track voltage flowing through a short - nearly 60 watts at 15V to the rails. However - the PSX breakers are rated to handle - hmm, the documentation doesn;t state a limit, though the max trip current is 19 amps and there is a note not to exceed 10.2 amps continuously unless you add heat sinks to the transistors - at any rate, if you can run it that high, then the insualtion on the transformer should not melt at those levels. And with only 5 amps available at the source, it's impossible to put 19 amps through the PSX. Accidently fed power int he wrong way? If anything, this would damage the transistors, not the current sense transformer. Transformers don't care which way the current flows - other parts might. All a mystery. --Randy
As stated in the initial post, the command station is tripping off the layout, which is the problem.