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Broadway Limited Paragon 3 SD7 shorts mainline every 3 to 6 feet

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  • Member since
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  • From: Moneta, VA USA
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Broadway Limited Paragon 3 SD7 shorts mainline every 3 to 6 feet
Posted by gdelmoro on Wednesday, June 27, 2018 10:14 AM

Ok leave it to ME.  I have one BLI P3 SD7 that shorts out the mainline every 3 to 6 feet.  No other BLI, Athearn, Atlas, Bachmann or Rapido loco does this.  The shorting location changes based on the loco’s last location. Usually NOT on a switch.

Reset decoder or call BLI??

Gary

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Posted by gdelmoro on Wednesday, June 27, 2018 10:20 AM

forgot to say that once the loco shorts the main breaker it comes back on by itself and runs another 1, 2 or three feet then shorts again.

Gary

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Posted by PHARMD98233 on Wednesday, June 27, 2018 11:04 AM

I am thinking this may be an inrush current problem.  Does it trip the breaker with the sound on the engine muted?

It may be that the breaker is set to trip at too low of a current draw.  Depending on which breaker you use, some have an adjustable trip current jumpers.  Also, the time delay may be adjustable.

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Posted by gmpullman on Wednesday, June 27, 2018 2:22 PM

gdelmoro
Reset decoder or call BLI??

I think BLI had a bad batch of Paragon 3 decoders. I had the same situation in a PRR H10. Give them a call with the details.

Good Luck, Ed

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Posted by richhotrain on Wednesday, June 27, 2018 5:29 PM

gmpullman
 
gdelmoro
Reset decoder or call BLI?? 

I think BLI had a bad batch of Paragon 3 decoders. I had the same situation in a PRR H10. Give them a call with the details.

Good Luck, Ed 

Probably not a bad idea, but before you send it back to BLI, disconnect the main line bus from the circuit breaker and connect it directly to the booster (or indirectly through the terminal block). If the loco performs OK, you may need to adjust a setting on the circuit breaker.

Rich

Alton Junction

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Posted by gdelmoro on Wednesday, June 27, 2018 5:30 PM

Well I shut the sound and it works fine. Turned sound back on and problem reoccurred.

I knew this loco‘s wheels get dirty so I figured I’d see what happens if I clean them. Turns out even though the wheels looked clean and shiny they were not clean.

Once I cleaned them. No shorts.

Never knew dirty wheels could cause a short. 

Gary

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Posted by richhotrain on Wednesday, June 27, 2018 6:51 PM

Gary, I don't think you have a short. It sounds like a stall due to the dirty wheels keeping the power from reaching the decoder.

Rich

Alton Junction

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Posted by gdelmoro on Thursday, June 28, 2018 5:26 AM

The reason I said short was that the Main PSX tripped and the other loco (elsewhere on the layout) shut.  The Main came back on and both loco’s came back when the BLI began to run again.  Very strange.

Gary

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Posted by richhotrain on Thursday, June 28, 2018 5:39 AM

It would be informative to bypass the breaker and see if the loco shuts down the booster.

Rich

Alton Junction

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Posted by selector on Thursday, June 28, 2018 10:51 AM

richhotrain

It would be informative to bypass the breaker and see if the loco shuts down the booster.

Rich

 

It seems they tried that and got the desired proof that it could be inrush after good pickup is restored.

I am always puzzled by the dirty wheels part.  I do know that locomotive tires do eventually need to be cleaned, but it is so seldom on my own layout that I usually begin to suspect I need to clean the rails, or clean them in a way other than what I have been doing if I feel I have somehow been maintaining their cleanliness.

This sounds like you need to take an hour or more one early Sunday morning before everyone else has stirred and have at them rails. Use a metal polish, or use isopropyl alcohol, and wipe them carefully, frequently turning the clean cloth.  No matter how many times you swipe a spot, you'll get plenty of discolouration grey on the cloth, so just just a couple of swipes should do it.

What works for me is a part of the 'gleam' process.  When I know my rail tops are wiped clear of any gunk, I run a large steel washer, rounded rim down, over my rails back and forth with only medium pressure, say 10-15 pounds.  Take your time; you want this to work without messing up your rails or your gauge.

There's no reason your loco tires should be getting covered often, if that seems to be what you're experiencing, unless your rails have some sort of organic material on them that gets carbonized or caramelized by hot microsparks all the time.

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Posted by richhotrain on Thursday, June 28, 2018 3:47 PM

THis makes no sense to me so maybe someone can explain it.

The loco shorts out the mainline every 3 to 6 feet.  

Gary shuts off the sound and it works fine. 

He turns the sound back on and the problem reoccurrs.

He cleans the dirty wheels. No more shorts.

So, I ask, how do dirty wheels cause shorts?

Rich

 

 

Alton Junction

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Posted by gdelmoro on Friday, June 29, 2018 5:51 AM

I agree with Rich! How do dirty wheels cause a short?? 

I can’t ignore the facts but that doesn’t mean I understand them Embarrassed

Gary

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Posted by rrinker on Friday, June 29, 2018 6:59 AM

 It's the repeated inrush. With dirty wheels, power is lost, the capacitor drains, wheels make contact again, cap charges up. Instead of getting a current inrush once, when first turning on power, it's getting one every time the contact is broken and regained.

                                     --Randy

 


Modeling the Reading Railroad in the 1950's

 

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

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Posted by gdelmoro on Friday, June 29, 2018 8:20 AM

Thanks Randy, always learn something from you guys!

Gary

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Posted by richhotrain on Friday, June 29, 2018 11:29 AM

rrinker

 It's the repeated inrush. With dirty wheels, power is lost, the capacitor drains, wheels make contact again, cap charges up. Instead of getting a current inrush once, when first turning on power, it's getting one every time the contact is broken and regained.

                                     --Randy 

Interesting. 

But is that a short or an overload that is shutting down the circuit breaker?

Rich

Alton Junction

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Posted by Arto on Friday, June 29, 2018 4:09 PM

FWIW The very first BLI loco I bought (PRR T1) (and this was before I switched to DCC) I had intermitant connectivity problems even with clean track. After cleaning the wheels I had no issues.

I've seen this on pretty much every new BLI loco I've bought. I recently bought a Zephyr set & a couple dozen refurbished P70. Same thing. Interior lights flicker when spanking new out of the box. Clean the wheels no problem. It seems to be very consistent with BLI for some reason.

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Posted by rrinker on Friday, June 29, 2018 4:15 PM

Capacitor inrush appears like a short, or at least a fairly high overload, depends on what the valus of the capacitor is and what the ESR of it is, but it would typically appear as a very low (few ohms or less) '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.

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Posted by richhotrain on Friday, June 29, 2018 5:04 PM

rrinker

Capacitor inrush appears like a short, or at least a fairly high overload, depends on what the valus of the capacitor is and what the ESR of it is, but it would typically appear as a very low (few ohms or less) 'short' 

So, it tripped the PSX circuit breaker set at 3.81 amps.

I wonder if it would trip the 5 amp booster?

I gotta say, I have had some seriously dirty loco wheels in my time, a few with a large buildup of crud, and I have never tripped any of my PSX circuit breakers.

Rich

                                      

Alton Junction

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Posted by gary233 on Saturday, June 30, 2018 6:46 AM

I agree, Ive had loco wheels that you could see dirt on and they have stalled (obviously) and when I cleaned them worked fine.  But I think there may be more going on here.  This loco had TWO bad decoders. The first would just stall randomly and BLI Sent me a new one.  The second would have sound come on when the layout was powe3red up no matter what I did to prevent that.  I sent it back and BLI replaced the decoder.

I have to wonder if that inrush is not exacerbated by some other electronic or connection flaw.  

Runs fine now.  Huh?

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Posted by wp8thsub on Sunday, July 8, 2018 12:20 AM

I only have a total of one BLI diesel on the layout, an SD40-2.  It more or less runs fine now, but exhibited a lot of problems with random shutdowns with the original QSI decoder and wiring.  I was able to eliminate the frequent stalling only by adding a keep-alive (a Soundtrax Current Keeper).  Without the keep-alive it was essentially unusable, regardless of how clean the wheels and axle bearings were.  It would stall all over the place, not necessarily on typical culprits like dead frogs.  

Rob Spangler

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Posted by gary233 on Friday, July 13, 2018 5:53 AM

Ok so the same thing happened on the inner mainline (the BLI was on the outer) with an Athearn Gen F3 A-B Set. Turns out there were several locations along BOTH mains that has visible dirt spots and sections that produced pretty dark lines on my cloth when I manually cleaned each line.  

This problem is new since I changed all the breakers and AR’s to PSX and has not happpened before. When trucks or track got dirty locos would stall or stop.  Now they short the mainline breaker which then resets and the loco tries to start again then trips the breaker Again.

NOW the tracks are spotless and all locos run without any hesitation or problem.

Here is my question. Is the breaker trip voltage too low? They are PSX at factory settings. Or is something else going on?

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Posted by loosecaboose73 on Monday, July 30, 2018 2:46 PM

Wow, I am glad I searched this subject in the forums. I just got word that BLI received my SD7 for repair. After reading the above entries I realize why it will tak 10 weeks before they look at it. I was having the same problems as in the entries above plus one even BLI had not heard of. After following all their instructions, it ran fine with only an occasional short. The wierd thing was the engine would be running and I would hear the comfirmation sound made when programing. The unit would continue to run, but the only control I had were lights and sound! I found that on my NCE PRO/cab I could, while still running, key in delete engine, enter the number, key in enter and regain control while still running. Weird. Should have stayed with Bachman, my Pacific runs great on the same 4'10" X 8' layout.

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Posted by loosecaboose73 on Saturday, August 18, 2018 3:16 PM

I just got my SD7 back from BLI. They said it would be 10 weeks, but I got it back within 3 weeks. They changed the decoder and fixed a couple of other things. Now it runs great. The sound is much more realistic. I take back anything bad I said about BLI.

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Posted by richhotrain on Sunday, August 19, 2018 5:33 AM

loosecaboose73

I just got my SD7 back from BLI. They said it would be 10 weeks, but I got it back within 3 weeks. They changed the decoder and fixed a couple of other things. Now it runs great. The sound is much more realistic. I take back anything bad I said about BLI.

 

Too late. We all went out and dumped our BLIs and bought Bachmann Pacifics based upon your advice.   Laugh

Rich

Alton Junction

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