PSX-1,2,3,4 AC Series circuit breakers

I Like em'. I have been using them for about four years now without  issue. I opted for the PSX 1's and am using a pair of them set for 12amps. I haven't had a derailment for some time now but confuse that when I did they trip in an instant. I set them up for manual reset rather then automatic and also installed the audible alarm. On top of that they also have built in over voltage protection (TVS). They are a bit pricey, but when you take into account how much you have invested in your motive power I think there a real bargain and a no-brainer.

Milwrd

+1. I got a PSX-1 a while ago, it has i believe saved my engines from having  an early demise at least twice. Imho, it's worth the price, when you think of how much an engine repair can cost. There was a lengthy discussion of them a while back-- but it's probably gone from the forum by now-- 

Have the PSX-2 for both my track loops running off my postwar ZW into the DCS TIU.  Saved my *** many times especially if there was a derailment but you didn't quite get all the car/loco wheels on the track properly.  Or a car/oco wiring suddenly develops a short, saving melted wiring.  Or you "made just this one little wiring change....."   They are very quick acting for a short, but ignores normal current fluctuations of locos and car light flickers, though I still left the fast acting 10amp in line before the PSX, just in case.

Only problem I was aware of was the instructions was not quite correct (may have since been corrected).  You have to make sure your transformer common goes through each PSX common to track common rails, and the transformer hot go into the PSX active circuitry then output to track center rail.   You can identify the PSX common by examining the board bottom to follow a heavy wide copper path from the PSX input terminal directly to the PSX output terminal.  The other PSX input terminal "disappears" into a maze of electronic parts.  If you get the inputs and outputs reversed with respect to transformer commons, weird things ocurr (why do I know this????).  I e-mailed the PSX makers of this but they never acknowledged a problem.

What about using them with the 180 Watt Lionel brick and the MTH DCS TIU?

Would they not be redundant?

Sam, does that mean that you could have a problem when the common is shared by several loops? 

The ZW meter has that same problem since you don't know which route the return current is taking.  (I was able to come up with a "current transformer" circuit that senses the current flowing from each of the HOT terminals, rather than the shared COMMON.)

I bought them after I saw a video posted on these forums a year ago. Just search PSX and you should find it. Right now I have 2 PSX-1s each hooked up between my ZW and my DCS TIU. One PSX 1 for each input into the TIU. I am confident that since I installed my trains have been very protected. I am in the process of always tweaking track and no matter how careful you are, eventually an engine wheel will end up not correctly seated on the track, or some piece of metal will find its way somewhere it is not supposed to be. 

I have never seen my engines spark, so the piece of mind is worth the price.

Hi Dale,

Well since my postwar ZW has all its neutral/ground commoned, and after some of my weird PSX operations, I realized that all the PSX "pass through" input to output common terminals have to go to the ZW commons, the PSX have operated flawlessly, with each PSX monitoring only its ZW hot terminal output.

I am not sure how things would operate with the bricks or if operators used different type transformers for loops.  Assume that as long as all outputs to tracks are phased alike, probably the return commons current phases would be alike and not cause the PSX to maybe possibly hiccup, but this is only a speculation guess on my part.

After reading the literature, I assume that the current sensing is on the HOT lead since the COMMON lead doesn't need to be hooked up for "common rail" configurations.

Yes it senses it via current transformer as I recall.  You however still need a common to each PSX common so board's power supply can operate, that runs the microprocessor and triggering the triac on/off to interrupt the AC hot  power lead to track.

Dale: I would REALLY APPRECIATE your considered response to the question raised by Don Grabski.....

I don't have a TIU, and I am not familiar with their innards and protection scheme. 

Yesterday I emailed the PSX vendor a technical question regarding how they sense current.  No reply yet.  One concern is that if they are using a Triac to control the power, you can't "untrigger" a Triac once it is triggered on any given half cycle.  You can only hold off triggering on the next half cycle.  Any current surge could last up to 8 milliseconds.  I would also like to know if they sense both halves of the sinewave.  The Powermaster only senses the current on one half and ignores the other half.

In my opinion, overcurrent surges are not much of a direct danger to our electronics boards since the fault current doesn't usually pass through the circuit boards inside the locomotives, but the voltage spikes they can create definitely need to be snubbed with Transient Voltage Suppressors.

The TIU has TVS protection on each channel, and it has a lightning fast over-current sense that shuts down the channel until you cycle power to that channel.  No need for extra fuses if you don't want them.

I just got one of these things and am not quite sure how to hook it up. I spent an awful long time in HO scale and understand DCC fairly well. This O scale electrical stuff is like trying to learn a new language! So far I can only speak in colors, such as "hook the red wire to screw 1 and the black wire to screw 2." In O scale I've always thought the red wire went to the center rail and the black wire went to the outer two rails. The instruction sheet for the PSX-1AC seems to show this reversed, with black going to the center rail and red going to the outer rails.

I'm using a power brick from an MTH Z1000 and running it through an MTH DCS TIU. Can someone give me some simple instructions for hooking this thing up using simple black and red terms? I can do alot of things but electrical isn't one of them!

Thanks,

Joe

Hi JoeDaddy,

Just opened my layout electrical "bible" to PSX chapter.  Examine your transformer or its instruction an determine which terminal(s) are common or ground.  connect a wire from a common terminal to PSX J1-1 or J1-3.  Connect a second wire from the transformer variable lever ("hot") output to PSX J1-2 or J1-4.   Connect a third wire from J2-1 to the two OUTSIDE rails of your three rail track.  Connect a fourth wire from J2-2 to the CENTER rail of your three rail track.  Turn on transformer and your train should repond normally.

The quick start diagram that came with my PSX board had J2-1 and J2-2 connections to 3 rail track reversed, but diagram may be corrected by now.

Hope this gets you going. Let me know if you are using DCS and I will explain that hookup, as I did not want to make this overly complex.

Sam,

Thanks for the reply. I am using the power brick that came from an MTH Z1000 and it has a barrel connector on the business end. I use an MTH adaptor to connect it to my MTH DCS system. I plan on wiring in the PSX-1AC between the power supply and the TIU. I think my instruction sheet is also backwards with respect to the wiring, so I'm not sure how it should be wired.

Thanks,

Joe

Assuming that the DCS is working correctly as wired now with MTH Z1000 brick, make the changes as follows:

The wire going to the DCS TIU channel black binding post will now move to the PSX J1-1 or J1-3 terminal.  The wire going to the DCS TIU channel red binding post will now move to the PSX J1-2 or J1-4 terminal.

Connect a wire from PSX J2-1 to the vacated DCS TIU channel black binding post. Connect a second wire from PSX J2-2 to the vacated DCS TIU channel red binding post.

The TIU channel output red binding post is connected to the track center rail, and the TIU black binding post is connected to the track outside rails as they were before, ie no change.

Thanks Sam, those are simple, straightforward instructions that a "dim bulb" such as myself can understand. I've installed all kinds of decoders, motors, etc. in my HO equipment with no problems but this O scale stuff with the AC has me scared to death!

Joe

Nothing to AC.  Just think of it as DC current that "viberates" 60 times a second!!  Same thing only different.  If you figured out all that complex DCC stuff and configurations and managed to squeeze 100 ounces of decoders and motors into a 5 ounce sized locos, this 3 rail stuff is then a piece of cake.

"Just opened my layout electrical "bible" to PSX chapter."......

Sam: Tho' I'm not usually a student of the bible, yours has piqued my interest!  Please elucidate.

Since I am lucky to remember my name from day to day, let alone what I did with the layout    , I have a three ring binder with every instruction sheet, excel spreadsheets of what wire color was used from terminal xx to terminal yy or where wires were joined at what terminal block where.  Saves a ton of time in trouble shooting and wire pulling.

Thus I was able to grab my "bible"  and open to the PSX breaker section and found where I had made a note of must switch output wires so J2-1 and J2-2 connect to correct rails.