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DC on a DCC wired layout question?

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  • Member since
    October 2019
  • From: Milton WV
  • 253 posts
Posted by Trainzman2435 on Monday, November 18, 2019 9:28 AM
Just wanted to let everyone know that i got it working. It was a bad connection of one of my BUS lines coming from the terminal strip under the layout lol.....Thanks to everyone for your help and suggestions!
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Posted by jjdamnit on Friday, November 15, 2019 2:49 PM

Hello All,

rrinker
The DC power pack should connect to the bus, same as the DCC system did, NOT just one set of feeders.

I agree!

Let's see what the continuity tests reveal.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Friday, November 15, 2019 2:29 PM

 If the DCC works, and there are no other DCC devices like autoreversers or electronic circuit breakers installed (the light bulb type will be fine), all you need to do is disconenct the two wires conencted to the back of the PwoerCab wiring panel and connect them to the variable DC of the DC power pack. That's it. If the DCC worked, the DC will work.

 If the DCC never worked, than there obviously is a wiring issue somewhere. If the DCC worked but this simple swap does not allow the DC to work, it almost has to be the DC pwoer pack.

 The DC power pack should connect to the bus, same as the DCC system did, NOT just one set of feeders.

                             --Randy

 


Modeling the Reading Railroad in the 1950's

 

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

  • Member since
    October 2019
  • From: Milton WV
  • 253 posts
Posted by Trainzman2435 on Friday, November 15, 2019 2:11 PM

jjdamnit

Hello All,

Thank you for your response to the more specific questions.

As a former electrician we used to say, "If it works it's a 'Fluke'!"

I still use my Fluke 23 Multimeter that I bought in the 1980s.

After you determine that the cab is working and puting out a varriable 0v-12v DC and you have hooked up your power feed wires to the correct output of the cab, I would do a continuity check.

Most Fluke meters have a continuity or "beeper" function [➔+)))].

Remove the wires from the cab.

Put one probe of your meter on one wire leading to your trackage (alligator clip attachments to the probes help). Then touch the probe to the corresponding rail on the first section of track.

You should only get a "beep" or open circuit on one rail.

Leave the probe on one wire and test the other rail.

If you get a "beep" from both rails without moving the probe to the other wire then you have a short.

This type of short can instantaneously fry a DC cab.

Once you have determined that there are no shorts from the track wiring, next reattach the track wires to the cab.

Without anything on the entire layout ramp up the DC cab to full power and meter across the two rails.

The voltage between the rails should match the output of the cab.

If you have a second meter put the probes of the second meter on the same poles of the output of the cab. The value of the meters should match.

In the DC mode of your multimeters, even if you reverse the polarity you will get a negative DC reading on one meter and a positive reading on the other.

Thank you for your willingness to answer further questions to help you resolve your problem.

And, as always...

Hope this helps.

 

 

Thank you sir for your time and suggestions....I will try this and report back.....:)

  • Member since
    October 2019
  • From: Milton WV
  • 253 posts
Posted by Trainzman2435 on Friday, November 15, 2019 2:09 PM

BigDaddy

JJ and I are confused by your throttle range from 13-13.6 V. 

Are you saying it goes from 13 - 13.6 or it goes from 0 to 13 - 13.6

 

 

Sorry about that, what i meant is that it will go from 0v up to around 13v to 13.6v as you turn the reostat.

  • Member since
    July 2007
  • From: Yorkton, Sk, Cnd
  • 441 posts
Posted by wvg_ca on Friday, November 15, 2019 12:57 PM

if it makes any difference, an auto reverser for DCC will not function under DC, the MRC brand just cycles ...just disconnect one of the two feeder wires ..

  • Member since
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  • From: 10,430’ (3,179 m)
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Posted by jjdamnit on Thursday, November 14, 2019 6:30 PM

Hello All,

Thank you for your response to the more specific questions.

As a former electrician we used to say, "If it works it's a 'Fluke'!"

I still use my Fluke 23 Multimeter that I bought in the 1980s.

After you determine that the cab is working and puting out a varriable 0v-12v DC and you have hooked up your power feed wires to the correct output of the cab, I would do a continuity check.

Most Fluke meters have a continuity or "beeper" function [➔+)))].

Remove the wires from the cab.

Put one probe of your meter on one wire leading to your trackage (alligator clip attachments to the probes help). Then touch the probe to the corresponding rail on the first section of track.

You should only get a "beep" or open circuit on one rail.

Leave the probe on one wire and test the other rail.

If you get a "beep" from both rails without moving the probe to the other wire then you have a short.

This type of short can instantaneously fry a DC cab.

Once you have determined that there are no shorts from the track wiring, next reattach the track wires to the cab.

Without anything on the entire layout ramp up the DC cab to full power and meter across the two rails.

The voltage between the rails should match the output of the cab.

If you have a second meter put the probes of the second meter on the same poles of the output of the cab. The value of the meters should match.

In the DC mode of your multimeters, even if you reverse the polarity you will get a negative DC reading on one meter and a positive reading on the other.

Thank you for your willingness to answer further questions to help you resolve your problem.

And, as always...

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    December 2015
  • From: Shenandoah Valley
  • 9,094 posts
Posted by BigDaddy on Thursday, November 14, 2019 5:23 PM

JJ and I are confused by your throttle range from 13-13.6 V. 

Are you saying it goes from 13 - 13.6 or it goes from 0 to 13 - 13.6

Henry

COB Potomac & Northern

Shenandoah Valley

  • Member since
    October 2019
  • From: Milton WV
  • 253 posts
Posted by Trainzman2435 on Thursday, November 14, 2019 5:18 PM

jjdamnit

Hello All,

 

 
Trainzman2435
i (sic) wired it exactly as the MRR article specified back in 2007 or 2008.

 

Unfortunately, that description doesn't really explain how your layout is wired. I don't have access to the source you loosly cited.

  • What scale are you modeling?
  • Are you using a bus with feeders?
  • A single output of the DCC booster to a terminal strip then individual feeders to the track?
  • Do you have power districts (blocks) and how are they powered?
  • Sectional or flex track?
  • If using a bus how far apart are the feeders?
  • What types and brands of turnouts?
  • Are the frogs powered or not?

 

 
Trainzman2435
I measured the DC voltage output of the power pack with my Fluke and it reads from around 13v up to 13.6v as you adjust the throttle.

 

On the back of DC power packs (cabs) there are typically three (3) outputs:

  • Track power; this is controlled by the "throttle" (rheostat) or knob. This will also have a "Direction" or "Forward" "Reverse" switch. If you put your meter on these outputs and move the throttle the DC current reading should range from 0v - 12v.
  • DC power; this is a constant voltage to power accessories like turnouts.
  • AC power; again, this is a constant voltage to power AC accessories like lights.

If you are metering the output of the cab while moving the "Throttle" and you are not getting a variance between 0v & 12v I suspect you are metering/using the wrong outputs of the cab.

Or, the cab is faulty and the rheostat is not functioning.

Also, the metered voltage of...

 
Trainzman2435
...13v up to 13.6v...

...DC is high for the maximum output.

 

You also have not specified what brand and model of cab you are using.

Answering these specific questions can help the great folks of these forums to help you resolve your questions.

Hope this helps.

 

 

jjdamnit, thank you and everyone else for helping. Let me see if i can answer your specefic questions better.....

 

  • What scale are you modeling? - N Scale
  • Are you using a bus with feeders? - Yes Sir!
  • A single output of the DCC booster to a terminal strip then individual feeders to the track? - Yes but i currently do NOT have anything DCC related attached to my wiring.
  • Do you have power districts (blocks) and how are they powered? - No
  • Sectional or flex track? - Sectional Kato Uni Track
  • If using a bus how far apart are the feeders? - Feeders are roughly every 12".
  • What types and brands of turnouts? - Kato No.4 Powered.
  • Are the frogs powered or not? - Powered but not currently hooked up to any current or wiring. Havent gotten that far yet lol.
  • "You also have not specified what brand and model of cab you are using." - Model Power 12v power pack and for DCC i am using the NCE Power Cab 2amp system for now.
  • Member since
    December 2015
  • From: Shenandoah Valley
  • 9,094 posts
Posted by BigDaddy on Thursday, November 14, 2019 3:20 PM

I wouldn't call myself an expert in anything electrical, but it shouldn't be this hard.  Either the OP is missing something obvious or the throttle is shot.

Henry

COB Potomac & Northern

Shenandoah Valley

  • Member since
    November 2013
  • 2,775 posts
Posted by snjroy on Thursday, November 14, 2019 3:00 PM

I don't think this has been asked a million times... As for the answer, I'm not an expert but I would make sure there are no DCC electronics connected to the track, like an automated loop, turntable, power booster, etc. I would also remove all DCC locos, except those that have been DC-enabled. Once that is done, and that you have resolved any return-loop issue, you should be able to plug anywhere on the layout, unless there are isolated blocks of course. A volt-meter (with the throttle on, of course) should indicate where there is power on the track. Maybe the real DCC experts on this forum can confirm.

Simon 

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    December 2015
  • From: Shenandoah Valley
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Posted by BigDaddy on Thursday, November 14, 2019 2:52 PM

Trainzman2435
I tried attaching the 2 DCC leads to the DC hookups on my power pack but got nothing.

That should have worked, but.....

13v up to 13.6v as you adjust the throttle.

isn't right.  I agree with the 2nd half of JJ's post.  Frogs and flex track and brands of track are just red herrings as far as I'm concerned.  Old DC throttles can go bad.

Henry

COB Potomac & Northern

Shenandoah Valley

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Thursday, November 14, 2019 1:27 PM

[quote

Where do i or how do i need to attach the 2 power leads from the DC power pack to my DCC wired layout or does it matter as long as i have one wire lead from the power pack attached to one rail and the other power lead attached to the other rail???? Thanks again everyone!

 

[/quote]

Should be good to go.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 2,311 posts
Posted by jjdamnit on Thursday, November 14, 2019 12:18 PM

Hello All,

Trainzman2435
i (sic) wired it exactly as the MRR article specified back in 2007 or 2008.

Unfortunately, that description doesn't really explain how your layout is wired. I don't have access to the source you loosly cited.

  • What scale are you modeling?
  • Are you using a bus with feeders?
  • A single output of the DCC booster to a terminal strip then individual feeders to the track?
  • Do you have power districts (blocks) and how are they powered?
  • Sectional or flex track?
  • If using a bus how far apart are the feeders?
  • What types and brands of turnouts?
  • Are the frogs powered or not?

Trainzman2435
I measured the DC voltage output of the power pack with my Fluke and it reads from around 13v up to 13.6v as you adjust the throttle.

On the back of DC power packs (cabs) there are typically three (3) outputs:

  • Track power; this is controlled by the "throttle" (rheostat) or knob. This will also have a "Direction" or "Forward" "Reverse" switch. If you put your meter on these outputs and move the throttle the DC current reading should range from 0v - 12v.
  • DC power; this is a constant voltage to power accessories like turnouts.
  • AC power; again, this is a constant voltage to power AC accessories like lights.

If you are metering the output of the cab while moving the "Throttle" and you are not getting a variance between 0v & 12v I suspect you are metering/using the wrong outputs of the cab.

Or, the cab is faulty and the rheostat is not functioning.

Also, the metered voltage of...

Trainzman2435
...13v up to 13.6v...
...DC is high for the maximum output.

You also have not specified what brand and model of cab you are using.

Answering these specific questions can help the great folks of these forums to help you resolve your questions.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    October 2019
  • From: Milton WV
  • 253 posts
Posted by Trainzman2435 on Thursday, November 14, 2019 11:16 AM

RR_Mel

Assuming the track rails are clean then; the right rail to one terminal on the DC power pack and left rail to the other terminal.  If the locomotive doesn’t run then either the locomotive has a problem or the power pack isn’t working.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
 

 

Mel, thank you for your input sir.....As for the rail, it is all clean. When you say to attach one wire to one rail and the other wire to the other rail, beings my layout is already wired for DCC, would it matter where i attach the wires from the DC power pack? I tried hooking the 2 wires from one of my feeders but it did not provide any power to the locomotive. Should the DC locomotive run when any of my many feeder wires are hooked to the DC power pack or is this the wrong way to hook DC power to the layout? Thanks again!

  • Member since
    October 2019
  • From: Milton WV
  • 253 posts
Posted by Trainzman2435 on Thursday, November 14, 2019 5:32 AM
Thanks everyone for the help. As for how i wired my DCC layout, i wired it exactly as the MRR article specified back in 2007 or 2008. My layout is "The Salt Lake Route in N Scale". I ran DCC equipped locos on it years ago before i had to store it and had no issues. I measured the DC voltage output of the power pack with my Fluke and it reads from around 13v up to 13.6v as you adjust the throttle. I do not currently have my DCC system hooked to my layout, i am just trying to use a power pack right now until i get my DCC decoders. My biggest thing is: Where do i or how do i need to attach the 2 power leads from the DC power pack to my DCC wired layout or does it matter as long as i have one wire lead from the power pack attached to one rail and the other power lead attached to the other rail???? Thanks again everyone!
  • Member since
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Posted by mbinsewi on Wednesday, November 13, 2019 7:50 PM

Trainzman2435
.My current layout is wired for DCC.

It might be helpfull to describe how you did the wiring for DCC, such as any "blocks" (isolated sections of track), feeders, etc. 

You do need to disconnect the DCC power, comletely, set it aside, then follow what Mel suggest.  Don't have the DCC and DC power connected, in any way, as Henry suggest.

Mike.

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    December 2015
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Posted by BigDaddy on Wednesday, November 13, 2019 5:29 PM

Can't argue with Mel, but whenever there is a question of why power is not there or insufficient, just measure it.  For less that the price of a domestic beer at a bar, you can buy a Harbor Freight voltmeter.   Good enough for DCC too.

Best disconnect your DCC throttle from the system.

Henry

COB Potomac & Northern

Shenandoah Valley

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Wednesday, November 13, 2019 4:59 PM

Assuming the track rails are clean then; the right rail to one terminal on the DC power pack and left rail to the other terminal.  If the locomotive doesn’t run then either the locomotive has a problem or the power pack isn’t working.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
  • Member since
    October 2019
  • From: Milton WV
  • 253 posts
DC on a DCC wired layout question?
Posted by Trainzman2435 on Wednesday, November 13, 2019 3:58 PM

Hello everyone, i know it has been discussed a million times but here is my question....My current layout is wired for DCC. Since i just began working on it again after some years i now find my self without a DCC equipped locomotive. For testing purposes, how do i go about hooking up a regular DC power pack up to my layout in order to just be able to run and test a non DCC equipped locomotive? I tried attaching the 2 DCC leads to the DC hookups on my power pack but got nothing. Where or how do i need to attach the 12v power pack to my DCC layout in order to be able to run a DC locomotive? Thanks everyone!

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