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Reversing loop has me in knots

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Reversing loop has me in knots
Posted by Travis N Scale on Tuesday, November 16, 2021 10:44 PM

Here is a diagram of my reversing zone, it’s wiring and the results of continuity testing across the insulating gaps. I was kind of surprised there was any continuity? I assumed there would be none since it’s supposed to be electrically isolated? 2 of the 4 entrances/exits of the red reversing district had continuity in both rails and 2 had only one rail with continuity. These results are marked in blue pen with the word TONE for continuity or NO TONE for no continuity. The results in blue pen occur when the reversing section on the PM42 is not tripped (the red light in zone #4 is off)

The results of the continuity test marked in red pen are the results when the reversing section IS tripped and the red light for zone 4 is on.

The blue circle is where I am having difficulty. I have no problem travelling through here in either direction when zone 4 is NOT tripped but is tripped by passing over this isolation gap. So with the PM42 zone 4 red light off, I can travel in either direction through here with no issues.

When zone 4 is ALREADY tripped (red light is on), I can travel through here from right to left with no issues BUT if I go through from left to right, the locomotive hesitates, then restarts on its own. I run the BLI locomotive muted through here and this hesitation causes the sound to momentarily unmute. The PM42 zone 4 light then switches off and everything goes along fine. REALLY has me stumped.

I have followed all of the advise above. I can provide another diagram with feeder wire locations if required.

Again my KATO passenger train flies through the exact same pattern with no issues.
I’ll include a picture showing the right side of the layout for context.

Appreciate all the time and assistance 

 

Ok can't figure out how to insert the photo from my iPhone

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Posted by MisterBeasley on Wednesday, November 17, 2021 9:19 AM

As you noted, the picture is not visible.

Is the PM42 a solid state device or a relay device?  That can make a difference if you're testing with a meter when the device is off.

What turnouts are you using?  The fact that the Kato passenger train works fine tells me the wiring is OK.  Is this HO or N gauge?  What model is the BLI engine? 

It takes an iron man to play with a toy iron horse. 

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Posted by selector on Wednesday, November 17, 2021 2:30 PM

I'm just fishing in the dark here, but some of the reversers have a setting for trip time.  BLI locomotives are historically notorious for disliking even brief interruptions of their track feed, no matter why it happens.  If it happens because your PM-42 is a little slow to reverse the phase, that may be just enough to cause your BLI decoder to balk.

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Posted by BigDaddy on Wednesday, November 17, 2021 5:50 PM

Welcome to the forum.  You are stuck in moderation for a short while. 

I tried to send you a pm and it's hopeless with 3 different browsers.  I was going to volunteer to post you picture.  It hasn't worked with Firefox for at least a year, but neither Chrome nor Edge would allow me to compose a message to you.

You can't simply attach a picture to your post, it has to be on the internet at a site like Imgur.com, not a site that requires a login like dropbox, google photos, facebook.  There is a sticky in the General Forum on how to do that.  Imgur is free.  Once you have a photo there copy the "BBLink" directly as text into you post.  Do not use the picture icon or the link icon.

Imagining a picture what we can't see makes it impossible to diagnose your problem.

 

Henry

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Posted by SeeYou190 on Wednesday, November 17, 2021 9:30 PM

Can anyone make sense of this?

Laugh

-Kevin

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Posted by SeeYou190 on Wednesday, November 17, 2021 9:43 PM

Travis N Scale
Here is a diagram of my reversing zone, it’s wiring and the results of continuity testing across the insulating gaps. I was kind of surprised there was any continuity? I assumed there would be none since it’s supposed to be electrically isolated? 2 of the 4 entrances/exits of the red reversing district had continuity in both rails and 2 had only one rail with continuity.

Welcome to the Model Railroader magazine discussion forums. We are very glad that you have found us. Your first few posts will be delayed by the Kalmbach Media moderators, but that ends soon enough, usually after just a few posts. Please stick around through the delay and become a permanent part of the discussions.

My first suggestion is to not use the term "continuity" for electrical troubleshooting, and never use a continuity tester to troubleshoot model railroad track.

Instead, use a digital volt/ohm meter (DVOM), sometimes called a multi-meter, as your troubleshooting tool. I am in love with the Fluke model 101 as a basic go-to-troubleshooting tool for model railroads, but there are less expensive options.

You need to know where you should see high and where there should be low resistance. Generally speaking, anything below 10 ohms can be considered a closed circuit, anything over 1,000,000 ohms can be considered open. In basic track circuits anything between 100 ohms and 10,000 ohms could be a problem and should be investigated.

This is why you need to learn what you should see. When you see 1.2 ohms where you would expect an open circuit, that is a problem.

Without seeing all the particulars of your layout, there is no advice I can offer directly.

Please stay around.

-Kevin

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Posted by gregc on Thursday, November 18, 2021 3:05 AM

Lastspikemike
Continuity isn't necessarily a surprise. At one end of a reversing section you should have continuity

seeing the same voltage when powered doesn't imply continuity.

continuity means a zero ohm path.  there's a bit of circuitry between the main and reverse section rails that result in a non-continuous connection.

a test for continuity, or the lack of it across gaps should be done without anything (i.e. AR) connected to at least the reverse section rails

greg - Philadelphia & Reading / Reading

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Posted by zstripe on Thursday, November 18, 2021 3:33 AM

I agree with Gregc on this...........

Take care! Smile, Wink & Grin

Frank

gregc
Lastspikemike
Continuity isn't necessarily a surprise. At one end of a reversing section you should have continuity

 

seeing the same voltage when powered doesn't imply continuity.

continuity means a zero ohm path.  there's a bit of circuitry between the main and reverse section rails that result in a non-continuous connection.

a test for continuity, or the lack of it across gaps should be done without anything (i.e. AR) connected to at least the reverse section rails

 

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Posted by SeeYou190 on Thursday, November 18, 2021 8:16 AM

gregc
seeing the same voltage when powered doesn't imply continuity. continuity means a zero ohm path.  there's a bit of circuitry between the main and reverse section rails that result in a non-continuous connection. a test for continuity, or the lack of it across gaps should be done without anything (i.e. AR) connected to at least the reverse section rails

Well put Greg.

Yes

-Kevin

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Posted by richhotrain on Thursday, November 18, 2021 8:52 AM

Without a track plan, we are at a considerable disadvantage. But, in my experience in dealing with reversing section issues, testing for continuity is something that I have never had reason to do.

Rich

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Posted by gregc on Thursday, November 18, 2021 9:41 AM

Lastspikemike
while at the other end at the same time attempting to test for continuity would show a dead short due to reversal of polarity or phase as the case may be.

mike

not sure how your comment is "practical".   continuity is a measurement of resistance.  mention of polarity/phase is irrelevant and confusing.

yes, the OP may be confusing continuity with polarity.   

greg - Philadelphia & Reading / Reading

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Posted by richhotrain on Thursday, November 18, 2021 9:42 AM

gregc
 

continuity is a measurement of resistance.  mention of polarity/phase is irrelevant and confusing.

yes, the OP may be confusing continuity with polarity.    

That would be my guess as well.

Rich

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Posted by Water Level Route on Thursday, November 18, 2021 12:06 PM

Travis.  I'm not a mind reader so will not pretend to know what you "obviously" meant.  I will suggest you look at the thread in General Discussion regarding how to post a photo and try again.  People are grasping at straws at the moment to try to help you out.  

Mike

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Posted by gregc on Thursday, November 18, 2021 5:33 PM

Travis N Scale
When zone 4 is ALREADY tripped (red light is on), I can travel through here from right to left with no issues BUT if I go through from left to right, the locomotive hesitates, then restarts on its own.

The PM42 zone 4 light then switches off and everything goes along fine.

can someone explain what the "red light" on and then off suggests?

why would the direction of travel make a difference?

looks like the PM42 Quad Power Unit is not purely an auto-reverser.   what if two adjacent "districts" managed by the PM42 are both configured as revering sections? 

greg - Philadelphia & Reading / Reading

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Posted by Steven Otte on Tuesday, November 23, 2021 9:08 AM

Argumentative posts have been deleted. Go to your corners, gentlemen. Answer the OP's question or don't post.

--
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Posted by mfm37 on Friday, November 26, 2021 8:30 AM

PR4 is actually 4 DPDT relays. As an autoreverser the relay for that reverse section will trip and reverse phase of the outputs as long as the wires are connected properly. Since thay are DPDT relays, there will always be a conection to one set of the relay's outputs even when power to the PR4 is off. When powered the PR4 will trip a relay to its opposit position if a short circuit is detected. When used as a circuit breaker, only one side of the relay is connected to the track. That is the side that is normally closed when the relay is not energized. This way there will always be track poewer to the section even if PR4's power supply is turned off.

Martin Myers

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Posted by Travis N Scale on Sunday, November 28, 2021 1:28 PM

Alright everyone, let's try this again with some pictures.

https://imgur.com/gallery/t0xIe2p

https://imgur.com/gallery/Vw1qA9Z

 

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Posted by Travis N Scale on Sunday, November 28, 2021 2:00 PM

Thanks for the replies everyone. Here are some image links. I will type a reply to some of your comments and questions as well as an update to some additional troubleshooting that I have tried.

 

https://imgur.com/gallery/t0xIe2p

 

https://imgur.com/gallery/Vw1qA9Z

 

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Posted by Travis N Scale on Sunday, November 28, 2021 2:11 PM

Thanks for the replies everyone.

To clarify, I am modelling in N scale using Atlas flex track and Peco Electrofrog turnouts controlled (and frog powered) through Walthers Switch Machines.

I am using a Digitrax DCS210+ booster, 2 DT602 throttles and a Zephyr DCS52 set as a booster though it is not connected as a booster. It is only connected with a loconet cable and is being used as my yard throttle.

I have aPM42 dividing the layout into a yard, mainline, reversing district (the red track in the image) and the switch machine track power bus.

An update - yesterday I set the PM42 reversing zone back to non reversing and installed a Digitrax AR1 instead to handle the reversing. No luck - same result though interestingly enough, when I installed it I reversed the Rail A & B without realizing it.

This changed the location where I was observing the problem from Entrance (or exit) 1 and 3 counting down from the top of the imageof the reversing section to 2 and 4. Very weird.

I'm convinced that it is an issue of inrush current to the sound decoders on the BLI equipment.

I've ordered a PSX AR to swap in place of the AR1 though I may end up having to replace the PM42 as well an replace that with PSX circuit breakers. Apparently the PSX AR does not operate well "downstream" of another circuit breaker.

Hopefully the PSX AR solves the problem with the BLI equipment - they claim to.

Failing that, my next step will be to rewire a large portion of the layout such that rail A (red wire) is toward the back of the layout always and create separate reversing loops at each end of the layout.

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Posted by Travis N Scale on Monday, November 29, 2021 1:52 PM

Hi everyone

Again I appreciate everyone's advice, questions and patience while I tried to sort out how to post the pictures.

Another clarification before someone worries - my Walthers Switch Machine zone coming off of the PM42 ONLY powers the physical movement of the switch machines. The track power that the switch machine routes to the powered frog is being supplied by the local track bus.

Spoke with Tony's Trains regarding the possible use of the PSX AR as a possible remedy here.

They confirmed that the Broadway Limited Imports sound equipped locomotives are particularly sensitive to these reversing situation. The inrush of current to keep the sound decoder capacitor "charged up" gets misinterpreted as a short circuit. The PSX AR claims to solve this.

They did caution that if the PM42 is remaining then the PSX AR must be installed upstream of the  PM42 off of the direct booster feeds. This prevents having two circuit breakers "arguing" with each other.

I hope that will solve it. If not then I will try replacing the PM42 with 3 PSX circuit breakers in addition to the PSX AR. At that point I may just have to rewire such that my reversing section has only 2 entrances/exits and there is a couple more reversing sections off to the right end of the layout.

Keep you all posted!

Oh and I am modelling the PRR and NYC railroads during the steam and diesel transition er.

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Posted by BigDaddy on Monday, November 29, 2021 8:58 PM

My kingdom for a picture.  Pirate

Ok let me think about it.

Henry

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Posted by Travis N Scale on Monday, November 29, 2021 9:59 PM

No if that track is removed then there is no way to return back into the yard. 
I'm hoping that keeping just that red reversing section to the left side of the layout but putting it on the PSX AR solves this.

The fact that the Kato runs over all of these reversing sectio entrances and exits going in all directions flawlessly is pointing towards it being an issue with the BLI Locomotives and the slower relay switches on the Digitrax PM42 and AR1.

I have 10 BLI locomotives and all have behaved exactly the same way - even with only one locomotive being on the layout.

My 5 amp power supply is more than enough.

I do have a back up plan of rewiring and reworking that one large reversing district and dividing it into the two sidings on the left side of the layout being one reversing district and all 3 tracks on the right side of the layout each isolated as separate reversing sections.

Thats a pile of work so it's the last resort if the PSX AR fails to solve the issue.

Here is what the reworked layout would look. The track in green can remain wired as is. The track in red is the new reversing tracks. All track not highlighted must be rewired so that Rail A is toward the rear of the layout.

https://imgur.com/gallery/Kh3xsjY

https://imgur.com/gallery/V9dOK33

https://imgur.com/gallery/Tc3lilI

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Posted by richhotrain on Tuesday, November 30, 2021 12:01 AM

Two comments.

One, I have been running BLI Paragons through PSX-ARs for years and years without a burp. Inrush of current, phooey.

Two, Digitrax AR1 is a dinosaur. Running a mechanical relay in tandem with solid state circuit breakers simply doesn't work well.

Rich

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Posted by Travis N Scale on Tuesday, November 30, 2021 12:29 AM

Thanks Rich

BLI has acknowledged that the inrush current to their sound decoder is an issue.

The PSX AR specifically claims to address this so here's hoping I have the same success you've experience.

Yes the Digitrax PM42 and AR1 seem to have been made for a by gone era and haven't been updated for today's locomotive models which is a shame as I quite like the boosters and throttles though the instruction manuals are terrible.

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Posted by richhotrain on Tuesday, November 30, 2021 12:46 AM

Travis N Scale

Thanks Rich

BLI has acknowledged that the inrush current to their sound decoder is an issue.

The PSX AR specifically claims to address this so here's hoping I have the same success you've experience.

Yes the Digitrax PM42 and AR1 seem to have been made for a by gone era and haven't been updated for today's locomotive models which is a shame as I quite like the boosters and throttles though the instruction manuals are terrible. 

The key to success with the PSX-AR is the settings, particularly J6 and J7. That said, I have always been able to work with the default settings "out of the box".

Good luck and keep us posted.

Rich.

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Posted by gregc on Tuesday, November 30, 2021 3:22 AM

Travis N Scale
BLI has acknowledged that the inrush current to their sound decoder is an issue.

is there a problem with other, non-BLI sound locos?

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Posted by rrebell on Tuesday, November 30, 2021 9:01 AM

What about using a frog juicer, they make one that can be used as a reverser.

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Posted by Travis N Scale on Tuesday, November 30, 2021 11:49 AM

Thanks Rich

Since my booster is 5amp, I'm thinking the default trip current (J6) should be fine and yes the J7 will have to have the jumper installed since I'm using a Digitrax booster.

Hi Greg

No the two non sound equipped Kato locomotives I have breeze through all 4 entrances and exits of that reversing district with no issues.

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Posted by richhotrain on Wednesday, December 1, 2021 5:56 AM

Travis N Scale

I'm convinced that it is an issue of inrush current to the sound decoders on the BLI equipment.

I've ordered a PSX AR to swap in place of the AR1 though I may end up having to replace the PM42 as well an replace that with PSX circuit breakers. Apparently the PSX AR does not operate well "downstream" of another circuit breaker.

Hopefully the PSX AR solves the problem with the BLI equipment - they claim to.

The fact that the Kato makes it through does not necessarily mean that the BLI locos are faulty. There is probably something electronically different in the Kato circuitry that gives it a pass.

The reason that a PSX-AR is not wired downstream from a circuit breaker is that the PSX-AR is not only an auto-reverser but also its own circuit breaker.

For years, I used Digitrax AR-1s to control the reversing sections on my layout with no problems. But, then I got the bright idea to divide my layout into power districts controlled by PSX units. That placed the AR-1s downstream from the PSX units, and conflicts began to immediately occur because the relay-based AR-1s could not react as fast to a short as the PSX units could. So, I had to replace the AR-1s with PSX-AR units which became their own power districts.

My feeling is that you will have to replace not only the AR-1s but also the PM42 since both are relay-based units.

Rich

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Posted by Travis N Scale on Friday, December 10, 2021 10:26 PM

Hi everyone 

An update - I've received and installed my PSX AR and things seem to be working perfectly.

I was having some hesitation in a BLI locomotive pair but now it was happening well after the train cleared the reversing district. When I gave the track and wheels a good clean (they weren't very dirty) I got no improvement. I THINK the train was just too heavy as when I ran just the locomotive through, it hesitated much less.

The section of track has fewer feeders than others so tommorw I'll put in a couple pairs of feeders there. All my trains do slow down there - it's a steeper grade on a curve plus the lack of feeders might be causing a further drop in power.

All in all I'm happy I went with the PSX AR for my reversing section over Digitrax.

I was careful to follow the directions and add the Digitrax jumper wire.

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