Date   
Re: DCC Wiring Problem on a Small N Scale Layout

thoms.chesley@...
 

Hi Greg

Thank you for your suggestions. I tested my locomotives and DCC system on a test track. Everything works. I have also made progress with my layout and I am happy to report that the sections of track I have installed and wired are working quite well with my DCC locomotives. I am being patient and meticulous to avoid any further issues. Thanks
Alan

Re: DCC Wiring Problem on a Small N Scale Layout

Greg Elmassian
 

Any updates?

Re: DCC Wiring Problem on a Small N Scale Layout

Don Vollrath
 

You DO have a DCC decoder in the test loco... right??
1. Use a separate piece of track wired directly to the DCC bus according to the NCE instructions for wiring it up and make sure you can control the loco as expected using your NCE PowerCab. If this doesn't work review your wiring of the Power Cab system and make sure you are addressing the loco with the correct DCC loco address. (see #2) If #1 works then the problem is somewhere in your layout track connections, etc. So...
2. Use a voltmeter and measure the AC voltage across the track section where the loco does not respond to DCC commands. There should be 10-16 Vac as measured on the track (the DCC power). Work your way out from the PowerCab Panel and make sure you have the Power Cab plugged into the correct RJ connector and are using the correct curly vs flat cord.

DonV 

DCC Wiring Problem on a Small N Scale Layout

thoms.chesley@...
 

Good Afternoon

I am relatively new to DCC and I have a few questions about wiring my layout. Here are the details of what I have done:

1. 3'x10' n scale unitrack layout (double tracked with several spurs) with number 6 turnouts (17 of them).
2. Turnouts are isolated with Kato plastic joiners at the diverging tracks of the turnout and then powered by Kato feeders (24 gauge wire).
3. My Kato feeder wires are going to be stripped of insulation, folded back to create a thicker wire, tinted with solder and then soldered to spade connectors.
4. All feeders are connected to 2 separate terminal barrier strips.
5. The bus wires (16 gauge stranded wire; 2 foot long sections) run from the barrier strips (one for each track) and connect to an NCE Power Cab DCC system.

I am trying to divide and conquer in a logical manner as I have already run into the issue of not being able to get a DCC locomotive running with even one feeder connection despite knowing that the feeders (I tested a couple of them randomly) will power a given section of track using DC. What am I missing here? Any suggestions would be greatly appreciated. Thanks.

T.-C.

Re: Wiring for DCC Update Announcemen

Gary Chudzinski
 

Good info guys...thanks!

Gary C

Re: Wiring for DCC Update Announcemen

Max Maginness
 

Arcing effects are less likely on DCC that with the low voltage  DC that the switch ratings are usually given for, because any arc is interrupted when the DCC voltage goes to zero as the polarity reverses.

That aside,  an 0.05 ufd capacitor has only about 400 ohms impedance at the 8 kHz fundamental frequency of the DCC waveform so if present across open contacts will leave the power still slightly on.

 

Max

 

From: w4dccqa@groups.io <w4dccqa@groups.io> On Behalf Of Gary Chudzinski
Sent: Wednesday, August 7, 2019 5:12 PM
To: w4dccqa@groups.io
Subject: Re: [w4dccqa] Wiring for DCC Update Announcemen

 

Alan,

On your website, “Wiring for DCC, Cutting Power to Yard or Roundhouse Tracks,” you state the following:  “Radio Shack carried a 12 position rotary switch, but it was only rated for 300mA. It might work for a while, but eventually may fail due to pitting of the contacts when used at higher currents”

In the smaller scales, where the locomotive draw current less, would it not be helpful to install capacitor(s), maybe  .01 - .05 ufd, across the contacts of a rotary switch?  Seems like I read something about this year’s ago that it can reduce/eliminate contact arcing, which causes pitting.  Or, am I mistaken about this procedure or capacitor value?  Maybe having a senior moment????

Enjoy your website....great information for the DCC learning curve!

Gary Chudzinski

Re: Wiring for DCC Update Announcemen

Don Vollrath
 

What Allan said is correct. Adding a capacitor across the switch may also further degrade the lifetime as the charged capacitor becomes short circuited when the switch closes. 

A capacitor across switch or relay contact is intended to act like a snubber to reduce sparking in circuits where the load is highly inductive, like a relay or magnet coil in DC circuits. 
DonV 

Re: Wiring for DCC Update Announcemen

Gary Chudzinski
 

Alan,

On your website, “Wiring for DCC, Cutting Power to Yard or Roundhouse Tracks,” you state the following:  “Radio Shack carried a 12 position rotary switch, but it was only rated for 300mA. It might work for a while, but eventually may fail due to pitting of the contacts when used at higher currents”

In the smaller scales, where the locomotive draw current less, would it not be helpful to install capacitor(s), maybe  .01 - .05 ufd, across the contacts of a rotary switch?  Seems like I read something about this year’s ago that it can reduce/eliminate contact arcing, which causes pitting.  Or, am I mistaken about this procedure or capacitor value?  Maybe having a senior moment????

Enjoy your website....great information for the DCC learning curve!

Gary Chudzinski

Re: Controlling power (0n/Off) in Staging Yard Tracks

Flash Gordon
 

You can use one toggle switch to turn off the whole yard.

Ed S

Re: Controlling power (0n/Off) in Staging Yard Tracks

george hohon3
 

Gary, you hit the nail on the head with this comment,  "Is this a small, one operator layout?"  The answer to your question is "Yes" . . . . that's exactly what it is.

George


From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of Gary Chudzinski <chudgr@...>
Sent: Tuesday, August 6, 2019 8:27 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: Re: [w4dccqa] Controlling power (0n/Off) in Staging Yard Tracks
 
Excuse my ignorance, but I'm finding it difficult to understand why one would prefer to use a rotary switch vs toggle switches besides fascia space.  Unless I'm missing something, a rotary switch would allow power to only one staging track at a time.  Is this a small, one operator layout?  Eight to ten mini switches can be compacted in a relatively small space extended below a fascia.  I can understand using a rotary switch in a roundhouse.
Gary Chudzinsk

Re: Controlling power (0n/Off) in Staging Yard Tracks

george hohon3
 

Jerry, you're right based on your railroad's operations.  I'm a single operator on a home based layout, and while I do run multiple trains at the same time . . . . yard operations are usually one train at a time.  So for me, the rotary switches were the perfect answer.

George


From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of Jerry Michels <gjmichels53@...>
Sent: Tuesday, August 6, 2019 9:34 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: Re: [w4dccqa] Controlling power (0n/Off) in Staging Yard Tracks
 
Wouldn't a problem with rotary switches be that  you can only turn on one track at a time? That wouldn't work for us considering a train may be entering the yard as another is leaving.  We need individual switches.

Jerry Michels
Amarillo Railroad Museum


Re: Controlling power (0n/Off) in Staging Yard Tracks

Gary Chudzinski
 

Excuse my ignorance, but I'm finding it difficult to understand why one would prefer to use a rotary switch vs toggle switches besides fascia space.  Unless I'm missing something, a rotary switch would allow power to only one staging track at a time.  Is this a small, one operator layout?  Eight to ten mini switches can be compacted in a relatively small space extended below a fascia.  I can understand using a rotary switch in a roundhouse.
Gary Chudzinsk

Re: Controlling power (0n/Off) in Staging Yard Tracks

Jerry Michels
 

Wouldn't a problem with rotary switches be that  you can only turn on one track at a time? That wouldn't work for us considering a train may be entering the yard as another is leaving.  We need individual switches.

Jerry Michels
Amarillo Railroad Museum


Wiring for DCC Update Announcemen

wirefordcc
 

All,

I have added a section on cutting power to yard and roundhouse tracks in my website.  You can find it at the What's New link at:  http://www.wiringfordcc.com/wirefordcc_toc.htm#a1

Allan Gartner
Wiring for DCC

Re: Controlling power (0n/Off) in Staging Yard Tracks

Max Maginness
 

More than you may want to know but the message is that the switching capacity of a simple rotary may be only 0.25 or 0.5 amps, but once closed the contacts can take several amps.  Might be a slight problem with high inrush current sound and /or lights when selecting a track.  

http://www.electro-nc.com/rotaryswitchbasics.pps

Max

 

From: w4dccqa@groups.io <w4dccqa@groups.io> On Behalf Of george hohon3
Sent: Monday, August 5, 2019 4:14 PM
To: w4dccqa@groups.io
Subject: Re: [w4dccqa] Controlling power (0n/Off) in Staging Yard Tracks

 

You can find almost any amp rating you need for a rotary switch at any good electronics parts store.  Mine have been in service for over ten years and they have been perfectly reliable in all those years.

 

George

 


From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of Don Vollrath <donevol43@...>
Sent: Monday, August 5, 2019 9:25 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: Re: [w4dccqa] Controlling power (0n/Off) in Staging Yard Tracks

 

Advisable? Yes. At least add the isolating gaps to do so. A toggle switch per track is the easy way. Most rotary switches don't have the amp rating for track power and may become unreliable. 
Necessary? Maybe. DCC locos (even ones with sound) don't really consume that much track power when idle. But lighted passenger cars can/do. Turnning power off makes the sometimes annoying sound go off and positively prevents any unwanted/mistaken locomotion.

DonV 

Re: Controlling power (0n/Off) in Staging Yard Tracks

george hohon3
 

You can find almost any amp rating you need for a rotary switch at any good electronics parts store.  Mine have been in service for over ten years and they have been perfectly reliable in all those years.

George


From: w4dccqa@groups.io <w4dccqa@groups.io> on behalf of Don Vollrath <donevol43@...>
Sent: Monday, August 5, 2019 9:25 AM
To: w4dccqa@groups.io <w4dccqa@groups.io>
Subject: Re: [w4dccqa] Controlling power (0n/Off) in Staging Yard Tracks
 
Advisable? Yes. At least add the isolating gaps to do so. A toggle switch per track is the easy way. Most rotary switches don't have the amp rating for track power and may become unreliable. 
Necessary? Maybe. DCC locos (even ones with sound) don't really consume that much track power when idle. But lighted passenger cars can/do. Turnning power off makes the sometimes annoying sound go off and positively prevents any unwanted/mistaken locomotion.

DonV 

Re: Controlling power (0n/Off) in Staging Yard Tracks

Don Vollrath
 

Advisable? Yes. At least add the isolating gaps to do so. A toggle switch per track is the easy way. Most rotary switches don't have the amp rating for track power and may become unreliable. 
Necessary? Maybe. DCC locos (even ones with sound) don't really consume that much track power when idle. But lighted passenger cars can/do. Turnning power off makes the sometimes annoying sound go off and positively prevents any unwanted/mistaken locomotion.

DonV 

Re: Controlling power (0n/Off) in Staging Yard Tracks

Clark Propst
 

I’ve seen it done with both toggles and rotatory switches. I used power routing switches on my 4 track staging, but one track is always powered.
 
Clark Propst
Mason City Iowa

Re: Controlling power (0n/Off) in Staging Yard Tracks

Jerry Michels
 

Bob,

We have an 8-track staging yard, and simply built a panel with 8 DPDT switches and brought a buss from the switches that runs under each track to provide connection to drops.  An LED installed on the switch illuminates when the track is powered.

Jerry Michels
Amarillo Railroad Museum

--

Re: Controlling power (0n/Off) in Staging Yard Tracks

Paul O
 

Bob, for every track (or group of tracks), isolate one rail on both ends of the track you want to control; insert a SPST switch in series with the isolated track(s) and the proper  bus leg for that rail.

Paul O

On Aug 3, 2019, at 6:17 PM, Bob Miller <cajonpass1995@...> wrote:

I have two 8 track staging yards at either end of my point to point layout. The main line run between the 2 yards is approximately 90 to 100 feet. Each staging yard is its own block and the main line is dividing into 6 blocks.

Question 1: Is it advisable to wire each track in staging yards so that power can be switched on and off, e.g. to permit arrival or departure of train, but eliminate the electrical draw while the track is empty or a train has completed its run.

Question 2: If this approach is advisable, what is the best way to wire the tracks? and could SPST toggles be used?