I currently have 2 PSX and a PSX-AR chained together as per instructions with the input to the 2nd PSX chained to the input of the PSX-AR. ?The instructions for the PSXX-AR show the AR being chained to the output of a PSXX.
What is the rationale for this change? ?Should I just chain the PSX-AR input to the PSXX-AR input or is a PSXX ( or? PSX) required in the circuit to protect the PSXX-AR?

The use of your word “chained “ is confusing. The INPUT wires of each PSX unit should be connected together, and be fed by the output of a booster. No PSX output should be feeding the input of another PSX or PSX-AR

DonV

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I have just hooked up 15 PSXX's to my layout.? With the output of two(2) of those PSXX's connected to the inputs of two(2) PSX-AR's, serving two(2) reverse loops, as per the instructions for the PSXX's.? I had contacted Tony's Trains asking the same question.? Here is their response.

Questions to Tony's Trains:

Which wiring method should one use and why, if you are using PSX-ARs and PSXXs, wiring a PSX-AR directly to DCC power verses wiring the PSX-AR through the J2 output of a PSXX?

What is the reasoning behind wiring a PSX-AR to the J2 output of PSXX vs. just wiring the PSX-AR straight to the DCC power?? They both have short circuit protection.

I can’t determine the reasoning behind wiring the PSX-AR to the J2 output of a PSXX in the PSXX manual.? The PSX-AR manual show wiring it directly to DCC power.

?
Answer from Tony's Trains:

We recommend connecting PSXX J2 to PSX-AR J1 so the PSX-AR zone receives the benefit of Current Limiting provided by the PSXX:

2nd Question to Tony's Trains:

I currently have the PSX-ARs hooked to the J2 output of the PSXXs as you have recommended.

What is the current limiting of the PSX-AR, or does it even have any current limiting if I was to hook up the PSX-AR directly to the DCC power?

Answer from Tony's Trains:

The AR does not limit current.

I think that the new PSXX-AR has current limiting whereas the older PSX-AR does not.

Hope this may help.
Bob Lessig
Union Pacific & Western.

?

?

Bob?
Thanks for your response, clears up most of my questions. ?I sent my query to Tony's earlier this AM.

My last remaining question is, since I am using PSX (and not PSXX), I should connect J2 (output on PSX) to inputs on my chained PSX-AR and then PSXX-AR.

Also thanks to mwbailey for posting the link to the PSXX manual. ?I have the PSXX-AR manual which I don't recall saying anything about backward compatibility with PSX. ?And neither manual addresses chaining PSX-AR and PSXX-AR to PSX J2 outputs.

If you look at the diagram with a reversing loop at each end… the PSXX-AR on the left side is powered from a PSXX. The one for the right end is powered directly from a booster. (One or two boosters makes no difference as they are supplying the same power)

This tells me that the PSXX-AR has it’s own over current shutdown mechanism despite power capability of the booster (not the same as current LIMITING).

I say always wire the input side of the PSXX-AR, or other AR controller, directly from the booster. Never from the output side of any other electronic breaker.

DonV

It is odd the Dcc specialities PSXX manual says “ Having the PSXX provide power to the PSXX-AR gives the AR unit the benefit of the PSXX CURRENT LIMITING function.” And then ?shows 3 diagrams with 5 out of 6 PSXXARs powered by the output of the PSXXs and the 6th powered directly from the booster.

?In addition, “The PSXX-AR acts as a “sub district” within the PSXX district” means that a short in any of these districts, including subs” will shut all of them down.

Jeremy/all,

? The term "daisy chaining" is tricky and you need to be careful how you use it ...

? There are two "outputs" on the PSX/PSXX series.? One is a 'daisy chaining' and is only
there for the convenience of wiring your layout.? It is on the same end of the board as
the input.? The other output is the 'true' output of the board and is on the other end of
the board.? It is best, when wiring your layout, to avoid ever having any -wiring- from the
output of any PSX/PSXX board to another PSX/PSXX board.

? Please note/pay attention to that I'm not talking about the track, just the wiring.??
However, when using any DCC track circuit breaker - it is best practice to double
gap the track at the breaker boundaries.? And, if the breaker is also a reverser?
that is -necessary- for proper operation of the breaker.? Reversing sections
need to be isolated from the rest of the layout.? And, in general, they need to be
"longer than the longest train that will ever be run thru them" - because if the
train (or two trains) crosses both boundaries at the same time it will "confuse"
the reverser and will be seen as a short instead of the need to reverse.

? Here is how reversers work.? When they see a short they immediately reverse
the polarity of the track they control (the output) and check to see if the short is
cleared.? If it is not they go into "Short mode" - if the short is cleared they leave
it reversed and the train will continue to run.
? And additional 'trouble' is if you have two reversing sections against each other.
When a train crosses that gap it can result in a hard stop of the train - or at
least a noticeable hesitation.? Even if the train is using a Keep Alive - although?
keep alives will usually get the train across this gap - but it may hesitate for
other wheelsets than just the first one and sort of 'stutter across the gaps' (if
you are using all metal wheelsets which is recommended).?

? I hope this clears up some of the confusion about what you are doing/what you are
reading in the manuals or here on the web.
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? - Jim in the PNW

Jim,
agreed I was overusing “chain”. ?All set on gaps and train length in my reversing loops.

re: ?“?It is best, when wiring your layout, to avoid ever having any -wiring- from the?output of any PSX/PSXX board to another PSX/PSXX board.”

In that case, isn’t it odd that Tony’s Trains and the manufacturer, in both PSXX and PSXX-AR manuals, recommend connecting PSXX J2 output to PSXX-AR inputs?

Jeremy,
? I -never- connect the output (J2?) of any PSX to wiring that ends up going to the input (J1?) of
another PSX? Or PSXX.? Or mix of both.? Never.? Can it be done?? My experience is "only
some times" and when you have a problem it can be a real head-scratcher to figure out why.
? These are my practices, based upon my experience(s).? Having wired about a half dozen
layouts for DCC (including several conversions from DC) and worked on the wiring of at
least a half dozen more ... this is a no-brainer ... for me.? YMMV.
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? - Jim in the PNW

So Jim in the PNW, you have said what NOT to do… so what DO you connect the power input to a PSX-AR or PSXX-AR or any other AR section controller to?

DonV

Don,

? Sorry, I left that detail out.? Here it is ...?

? I connect the -input- of any PSX/PSXX (AR or not) to a bus line that comes
'directly' from the booster.

? I use the PSX/PSXX devices to establish "breaker districts" and the booster(s) to
establish "booster districts".? A bus line from the booster can be daisy chained
from one PSX/PSXX to another ... on the -input- side.? There are even extra
connections to the PSX/PSXX specifically meant for that purpose - it's the end?
that has 4 connectors.? The output end only has one set of contacts (one pair)
and goes to the track for that breaker district.
? Those extra connections on the input side of the breaker do not go "thru" the
breaker - they are directly connected to each other right there on the board.? They
are there for the convenience of wiring up the booster district.

? Does this help clear it up?
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? - Jim in the PNW

P.S. Please note - the terminology I am using is very specific - and, to me at least,
? ? ? ?also very important.? It helps me to wrap my head around the important
? ? ? ?difference?between a breaker district and a booster district.

FWIW One more data point on this: ?the DCC Guy on YouTube reviewed the PSXX-AR (?)

Jeremy said ...

? I’m still uncertain of any compatability issues between wiring psxx-ar to a PSx output.??

? Look at it this way - the output of any PSX is supposed to connect to "track it is protecting".? If
you connect the output side of any PSX to another PSX (any PSXX, AR, etc.) then you can have
"timing issues" with respect to which PSX trips and whether or not both of them trip.? And the
behavior can be 'sometimes it works sometimes it doesn't' or sometimes it works one way and
the next time a different way.

? The simplest method is to use the daisy-chaining connections of J1 ("input") in order to
connect up?a second (or third, etc.) PSX.? Although it is possible to have the input of a
PSX device (again?any to/from any)?connected to?the output of another PSX and
everything will work as desired.
? The more common result is for trains crossing that boundary to either stall and have to be
pushed across the gaps - or hesitate and then move ... sometimes it is several hesitations
before it will run normally.

? Does this help?
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? - Jim in the PNW

So the right answer for best operation is to always connect the INPUT wires of a PSX.. or PSX AR or other brand/type circuit breaker or AR controller directly from the booster.

DonV

Juergen,

? Your situation is - almost always - caused by one or more "wiring errors".? Think about your wiring
this way?

? Every booster district is separated from all other booster districts by double gaps ... everywhere.
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?- and -
? Every breaker district is separated from all other breaker districts by double gaps ... everywhere.

? The most common wiring errors are either the double gaps aren't working (unlikely but not?
unheard of) or there are one of more sections of track bus that have feeders that cross booster
or breaker districts (the same track power bus is wired to track on more than one booster/breaker
district).

? "Divide and Conquer".

? The best way to find these is to first find out 'what's really happening' ... by cutting power (removing
the connections at a terminal block?) to all of the districts and then connecting them back up One At A
Time - all the while testing what track is/isn't powered (RRamp meter, light bulb, old style meter).
After you have figured out which track blocks are connected when they shouldn't be -then- go under
the layout and figure out where the incorrect wiring is.?
? Somewhere you have two (more?) districts connected to each other.

? Often the layout owner won't even know this wiring problem has happened - because trains will Run
fine ... until?there is a short (somebody runs a turnout or a derailment) and then trains in more than one
district?will stop/come back alive after the short is cleared.

? The whole purpose of having booster/breaker districts is to isolate others from the shorts that you
experience - as much as possible.
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?- Jim in the PNW

P.S. If you live in the PNW contact me - off list - and I'll see if we can set up a time for me to visit.