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PM42 operation

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WPA
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Posted by WPA on Friday, March 29, 2019 4:06 PM

After reading Randy’s post it makes sense now.  When it tripped all before it was a hard trip and that was likely the booster as he said. My last N scale layout was late 1970’s so really starting from almost scratch knowledge again.  Thanks

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Posted by BigDaddy on Friday, March 29, 2019 3:01 PM

WPA
“Try increasing your shutdown timing on the 4 districts. It may be too sensitive with your current settings.“

rrinker
Setting the PM42 to "faster" makes it respond faster than the booster on its default setting

I'm glad the OP solved his problem, and I what Randy explains, is what he did and makes sense, but it sure seems opposite to what Digitrax advised. 

Maybe I caught the wrong end of the stick again.

Henry

COB Potomac & Northern

Shenandoah Valley

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Posted by rrinker on Friday, March 29, 2019 2:47 PM

 I'm guessing it wasn't the other PM42 districts tripping, it was the booster. Setting the PM42 to "faster" makes it respond faster than the booster on its default setting. Now only the affected PM42 section shuts off when there is a short.

                         --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

WPA
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Posted by WPA on Friday, March 29, 2019 2:37 PM

Below is what Digitrax sent me.

“Try increasing your shutdown timing on the 4 districts. It may be too sensitive with your current settings.“

I changed it from standard to Faster per the manual.  I guess faster works better with N scale because that fixed it.  The trip in one sub district now seems more subtle and does not trip the others.  Onward.  Thanks for responses and recommendations.  

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Posted by rrinker on Sunday, March 24, 2019 11:10 AM

 Mp, you should be able to take the two bus wires from one section the the PM42 and twist them together and only that one section should trip out. I would check the gaps between each section, and the feeders and bus wires just to either side of the gaps to make sure you don;t have a gap that has closed up (BOTH rails need to be gapped) and that you don't have a feeder across to the wrong side - like a feeder from section A connected to the rail of section B.

 If you're getting continuity through all sections - this is definitely the problem. Maybe you have the wires on the edge connector upside down. Or have each section hooked up following the reversing section diagram from the manual. The breakout board from Acculites is the easiest thing to use, but if you wire directly to the Digitrax connector there's nothing wrong with using short sections of thinner wire to make it easier to attach. Run them to a terminal strip, and then run the heavier bus wires out the other side to the layout.

                                  --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

WPA
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Posted by WPA on Saturday, March 23, 2019 7:37 PM

Thanks for the input. Messed around a little more with a small window of free time and noticed if I lightly, quickly trip the sub district it works as it is supposed to, not tripping the other sub districts.  Maybe my checking it is too much of a trip and at some point it trips all by design.  I am just touching the rails with a small screw driver but the sensitivity may be more than expected.  Have a few switch motors to hook up and may be good to move on until I see what Digitrax says.  

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Posted by BigDaddy on Saturday, March 23, 2019 11:48 AM

Acculites.com makes a breakout board that would make troubleshooting easier.

Breakout Board

I would remove a power district, one at a time, from the PM42 and check for continuity with the other districts.  There should be none.

EDIT Question for the electrical gurus.  Can he measure continuity, without disconnecting from the command station?  Seems to me there might be continutity backwards?

Henry

COB Potomac & Northern

Shenandoah Valley

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Posted by WPA on Saturday, March 23, 2019 11:32 AM

sent the question to Digitax.  New to this so could be missunderstanding but seems to me separate circuits should not all trip at same time.  

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Posted by BigDaddy on Saturday, March 23, 2019 11:19 AM

It would explain your symptoms, though.

Henry

COB Potomac & Northern

Shenandoah Valley

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Posted by WPA on Saturday, March 23, 2019 10:56 AM

Now confused.  No crossed feeders.  I see continuity across all districts which does not make sense.  I thought they were on separate circuits so if one trips the others should not trip.

WPA
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Posted by WPA on Saturday, March 23, 2019 8:47 AM

Hoping to dig into it today.  Anyone reading this wrestling with soldering to the PM42 I saw someone use Molex pin connectors #02-06-1101.  I ordered them from Amazon, $7 total shipped and best move I made.  The pins are a little small on the wire end for the 16 gauge I am using but soldered in was fine.  Used a small pin awl to spread the opening end for the board just a little to slide on and soldered them in place with a quick dab.  They are close to each other so heat shrink or a black tape wrap is needed.  

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Posted by BigDaddy on Friday, March 22, 2019 7:47 PM

Your thread was one of the ones I meant, although I didn't recognize you were the OP.

http://cs.trains.com/mrr/f/744/p/275028/3137243.aspx#3137243

Here are the others, though I'm not sure there are answers.

http://cs.trains.com/mrr/f/744/p/275052/3136075.aspx#3136075

another

http://cs.trains.com/mrr/f/744/t/274846.aspx

http://cs.trains.com/mrr/f/744/p/266371/3012030.aspx#3012030

Henry

COB Potomac & Northern

Shenandoah Valley

WPA
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Posted by WPA on Friday, March 22, 2019 7:28 PM

I did search the forum ahead of posting and did not see the ones Bigdaddy mentioned.  Will look again.  Using a DCS210 booster/station.  Wired up like the manual Example A.  I shorted one of the districts that are wired to the PM42 and I see all red lights light on the PM42, meaning all four districts shorted. Does not seem right. I have to revisit my feeders but have just enough time to catch up now.  Using a meter I am getting continuity between rails that are separated by an insulator which means I may have feeders crossing bus lines so may start there....thanks

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Posted by mbinsewi on Friday, March 22, 2019 10:18 AM

Yea, well, Randy must still be on his work assignment, so I just looked at the instructions, I don't have a PM42, but it says it protects up to 4 power districts, so did you short one of the districts that are being controled through the PM42?

I don't know how you have yours wired, I'm guessing Diagram 1, example A ?

I use Digitrax, but I use the bare minimum of features, just to run trains.  I don't need any power management on my small lay out.

Mike.

 

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Posted by AlienKing on Friday, March 22, 2019 10:05 AM

What command station do you have?

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Posted by BigDaddy on Friday, March 22, 2019 8:18 AM

Seems to me there are two other threads with similar problems with the PM42. 

Not a digitrax guy, but there is a search box on the right side of this page, about 1/2 way down.

Henry

COB Potomac & Northern

Shenandoah Valley

WPA
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PM42 operation
Posted by WPA on Thursday, March 21, 2019 9:14 PM

I hooked up a Digitrax PM42 to a Digitrax system and was running an engine in one district and shorted another to test it and the engine stopped in the district I did not short.  It did restart but thought it was supposed to segregate it so other districts would not be effected.  Wired it as shown in manual. Still figuring DCC out. Is this normal, could not find much on this issue.  Thanks!

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