DC block wiring

[SeeYou190]

mikeGTW

Quick question  so from what you are saying I can not run an engine anywhere in seperate blocks in opposite directions using common rail?

You can wire a common rail set up, hook up two Isolated power packs, and run at opposite directions under the control of the two different packs in DC using cab selector switches on the blocks.

There are situations where problems might arise, like long lighted equipment, locomotive consists wired in parallel to one another, some "dual packs" that are not isolated, etc.

Under normal operating you should never have a problem, and common rail works completely fine. It is just not my preference.

-Kevin

[RR_Mel]

mikeGTW

Mel quick question  so from what you are saying I can not run an engine anywhere in seperate blocks in opposite directions using common rail?

I use common rail (kind of)  and can run in opposite dir on my mains at the same time   So this should not work?    I have 5 throttles 3 hard wired and two on plugs  Not sure what I'm doing different but it works just fine

 

 

 

Not using the same DC power pack.  You can reverse the polarity if both rails are switchable but you have to be carful not to go into a block with the opposite polarity, a short will occur as the wheels close the gaps.

Early on in my teens I accidently melted the springs in my 0-6-0 tender trucks.  Back then I was using an AC transformer for my power and a selenium rectifier with a rheostat and the fuse wasn’t fast enough.

As Kevin said you can use two isolated power packs with common rail but should you cross into a block powered with the other power pack disaster.  The two voltages will add together and ZAP.


Mel



 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.

 

[mikeGTW]

Mel   you are correct  the only thing different I would say is seperate transformers  cause some store bought ones used the same one for two controls  

And like you been at this for prob 50yrs    30+ signal dept on the real thing   

I was repairing and troubleshooting  motion sensors and predicters for the real ones when I retired  so electronics is not a problem for me 

You think some of our model stuf can run you in circles   try the real ones

[rrinker]

 It really goes back to those dual power packs that were popular back in the day. There are two kinds, and for common rail you need to be careful of which type you use. The more common adn cheaper ones ahve a single transformer and rectifier, and then 2 rheostats and direction switches. The more expensive ones are actually two COMPLETE packs in a case, they just have the transformer primaries connected to a single line cord.

 Transformers provide isolation. But if the two outputs come off the same transformer secondary, they are not isolated from each other. This is where the problem comes in. Common rail cannot work if there is only a single shared transformer.

                                           --Randy

[richhotrain]

Lastspikemike

Experts frequently believe their expertise gives them an advantage in explaining these things. It doesn't. Believe me.  

Never?

[RR_Mel]

I’m not going to argue you will only nitpick anything I say.  At least you finally read his post and replied.


Mel



 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.

[richhotrain]

RR_Mel

 

Please give me a bit of credit, I was very successful in electronics for over 50 years.  

But, Mel, did you get straight A's in mathematics???   

Rich

[SeeYou190]

- -

Experts frequently believe their expertise gives them an advantage in explaining these things. It doesn't. Believe me.

            

Unbelievable. Claiming you are better qualified to explain something than the people who are experts.

And I thought it was bad when my intelligence was called into question because I did not have a passport.

Where do we go from here?

RR_Mel

I’m not going to argue you will only nitpick anything I say.

We are deifnitely dealing with a strange sort of online bullying here. Do not argue with him, it is a waste of effort.

I really need to wonder about the motivations of someone who so desperately craves public victory in an electric train forum.

richhotrain

But, Mel, did you get straight A's in mathematics?

I wonder why that was even pointed out?

I have had disagreements with people in here and never once thought that mentioning my marks in the long gone days of academia would bolster the validity my point of view.

What do you know?

-Kevin

[richhotrain]

SeeYou190

We are deifnitely dealing with a strange sort of online bullying here. Do not argue with him, it is a waste of effort.

I really need to wonder about the motivations of someone who so desperately craves public victory in an electric train forum.

-Kevin 

Exactly my sentiments, Kevin. All of this braggadocio about college grades, courtroom domination, always being right and sometimes, even "righter", and all on a model railroad forum of all things. Worse yet, it is entirely unprovoked.

I recall my first post-retirement winter in Florida at a golf resort. On my first day playing in a group shotgun format, the group leader introduced himself, welcomed me on board, and took great pains to point out to me that no one in the group cared what I did before I retired whether it be a CEO of a Fortune 500 company, a king or emperor, or whomever. They just care about your handicap, he reminded me.

That same advice holds true on this forum. We just care about your layout, what you model, and maybe a photo here and there of your work. We don't need encyclopedia-like disserations to make a point.

Rich

[hgodling]

dknelson

 

I believe the popular Atlas block control components (and thus the Atlas wiring books) assume common rail.  Westcott's old wiring book shows both.

Dave Nelson

Thank you for sharing your experience Mel. Sounds like it could save me some headaches when I get to that point. 

Does the Westcott book actually refer to this as common rail?

I have a copy of his book from 25+ years ago that I was planning to use, but based on Mel's comments I think it's a safe bet that I want to avoid those issues. I didn't know if names have changed over the years. 

[RR_Mel]

Common Rail will work but some aspects don’t appeal to me.  I prefer to switch both rails.  I don’t have the Wescott book nor have I read it.

I often have a DC train running my twice around mainline and I can still do switching in my yard, actually just moving a locomotive around in my yard.

I also do other things that don’t conform to common rail, I have siding that I park passenger trains on and I use onboard batteries that trickle while running but when parked on a siding I can switch 12 volts to the siding to charge the batteries.  I also have a yard storage track with the same feature for cabooses.

My layout is dual mode DC or DCC, both rails switched has worked perfect on my layout for 31 years.  No special switches or wiring, everything is normal.  

When I cutover to DCC in 2004 the only wiring change was a relay to switch from DC to DCC powered off the DC power pack to prevent both controllers from being connected to the track.  When I turn on the DC Power Pack (MRC Sound and Power 7000) the relay pulls in and switches the power packs.


Mel


 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.

[Medina1128]

ATLANTIC CENTRAL

Are you suggesting SPDT switches and common rail? I've been using DC cab control for 53 years and do not recommend common rail wiring. Maybe later when I am not working I can take the time to explain why. Sheldon

The reason I didn't wire my DC controlled layout for common rail is that I have reverse loops. Once a train enters the reverse loop, you must reverse the polarity of the block leading into the loop. In order to do this, you need to isolate both rails.

[RR_Mel]

Lastspikemike

 

 

Medina1128

 

 

ATLANTIC CENTRAL

Are you suggesting SPDT switches and common rail? I've been using DC cab control for 53 years and do not recommend common rail wiring. Maybe later when I am not working I can take the time to explain why. Sheldon

 

 

The reason I didn't wire my DC controlled layout for common rail is that I have reverse loops. Once a train enters the reverse loop, you must reverse the polarity of the block leading into the loop. In order to do this, you need to isolate both rails.

 

 

 

 

You can still use common rail for all the track outside the reversing loop.

Check the wiring diagram for the Atlas 220 controller (in the Atlas wiring book) and you'll see why.

 

He said it was working, why do you keep mucking everything up?


Mel


 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 

[Overmod]

RR_Mel

 

Lastspikemike  

Medina1128 

The reason I didn't wire my DC controlled layout for common rail is that I have reverse loops. Once a train enters the reverse loop, you must reverse the polarity of the block leading into the loop. In order to do this, you need to isolate both rails.  

You can still use common rail for all the track outside the reversing loop.

Check the wiring diagram for the Atlas 220 controller (in the Atlas wiring book) and you'll see why. 

He said it was working, why do you keep mucking things up?

In all fairness, he made a legitimate comment here in context, and in fact backed it up with a reference.  What he is saying -- very appropriately in context, imo -- is that simply because you have reversing loops does not mean you can't use common-rail for 'the rest of the layout'.  And I do think that is important to have established at this point in the discussion.  I expect Sheldon might now weigh in not just eith reasons he doesn't use common rail but with specific criticism of the Atlas approach to reversing loops ... if there is some.

Personally I have disliked common-wire since before my teens and have always been a full-isolated-section kinda guy, so I'm not in any way advocating common rail.  But a civil post with legitimate observation backed up by better than arrogance doesn't deserve a dismissive response...

[RR_Mel]

I have a EE Degree and 50 years in Two-Way Radio Communications as well as 15 years in Radio & TV broadcast engineering and I have been Modeling HO for 69 years most likely all longer than he has been on this planet and he berated me.

Thanks to him the first time OP on this post probably won't stay.


Mel



 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 

[gregc]

Lastspikemike

You can still use common rail for all the track outside the reversing loop.

i agree

you don't need a degree to understand this.  see Linn Westcott's book

[Overmod]

RR_Mel

I have a EE Degree and 50 years in Two-Way Radio Communications as well as 15 years in Radio & TV broadcast engineering and I have been Modeling HO for 69 years most likely all longer than he has been on this planet and he berated me.

I know.  And I found it frankly appalling that he would do so.  But in the particular post in question he appeared to be very careful to stay objective and fact-based, and non controversial in either tone or expression.

Thanks to him the first time OP on this post probably won't stay.

Yes ... but that in itself is no reason to prejudge his ability to post reasonably when he chooses to do so.

I don't think advocacy of common rail is a 'sin' or that its use is a kind of anathema, even though I dislike it.  As Riddles said to Bulleid "if doctors can differ then so may engineers" and if kept objective, such a difference is not implied insult (or implied iconoclasm!)

[richhotrain]

Dunno, when I first read the comment, I took it the same way that Mel did. Maybe the problem here is that once bitten twice shy. There has been so much sniping going on in the forum lately that it sometimes becomes difficult to separate the sincere from the insincere. In fairness to Mel, he didn't say that common rail couldn't be used on a layout with reverse loops.

Rich

[RR_Mel]

I agree common rail will work, I’m not against common rail it’s just not the way I prefer to wire a layout.  My MAD was because he berated me for no reason.  I was trying to help the newbie not confuse him.

 

EDIT:  I ask Tom to block this before it gets really bad.

Mel



 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.

[Overmod]

richhotrain

In fairness to Mel, he didn't say that common rail couldn't be used on a layout with reverse loops.

I don't even think Mel raised the issue of reversing loops not working with common rail in the first place.  It's that the atmosphere has been so poisoned by the overweening arrogance that he promptly felt any comment to be a jab ... it just so happened that this one wasn't.

I grew up in northern New Jersey, where chopbusting is almost the official state pastime and asserting opinions in discussions strongly regardless of participant reputations is perhaps second only to that of the New York theatre community.  That would not give me the right to question "credentials" of any of the serious modelers here as if their knowledge or wisdom were somehow deficient.

[richhotrain]

Overmod

 

richhotrain

In fairness to Mel, he didn't say that common rail couldn't be used on a layout with reverse loops. 

I don't even think Mel raised the issue of reversing loops not working with common rail in the first place.  

LOL, that is so true. It was poor Marlon (Medina1128) who raised the issue in the first place. Happy Saturday Evening everyone!  

Rich

[RR_Mel]

I think I’m over my mad.  I hope the newbie hangs around, this was an unusual experience and I shouldn’t have come unglued like I did.  I apologize for my rant.

Just not used to someone taking a shot at me, that one hit me dead center.

Not offering excuses but the Bako heat doesn’t help, it’s 104° at 27% H outside on the way to 106° and the AC is working overtime.


Mel



 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.

[tstage]

Wow...another locked thread on a weekend.  Never a dull moment on the forum...