Feeder connections


John DeSantis
 

Hello all,

What are your thoughts on A vs B wiring Feeders to the bus. I'll be using a Star configuration for the bus wires. I'm converting an existing DC layout to DCC and tight on space for wires.

Thanks for your input,
John D.


Allan AE2V
 

Hi John,

Can you elaborate on what you mean by A vs. B wiring feeders?

The conventional wisdom is attach feeders every 3 to 6 feet.  As far as feeder size and length, see the table in my website at:  https://wiringfordcc.com/track_2.htm#a14

Hope this helps.

Allan Gartner
Wiring for DCC


John DeSantis
 

Hi Allan,

 Thanks for your timely reply.  On image A there is one feeder each on opposite ends of the section of track. On image B both feeders are on the same end of the section of track. 
Does it really matter? 
I'm working with a layout table that is already assembled from 4 2x4 sections joined together. So I have the joints of those sections to deal with. That's why I'm asking. 

John 


Sent from my Verizon, Samsung Galaxy smartphone


-------- Original message --------
From: Allan AE2V <bigboy@...>
Date: 9/7/22 7:24 PM (GMT-05:00)
To: w4dccqa@groups.io
Subject: Re: [w4dccqa] Feeder connections

Hi John,

Can you elaborate on what you mean by A vs. B wiring feeders?

The conventional wisdom is attach feeders every 3 to 6 feet.  As far as feeder size and length, see the table in my website at:  https://wiringfordcc.com/track_2.htm#a14

Hope this helps.

Allan Gartner
Wiring for DCC


Allan AE2V
 

John,

If you place your feeders every 3-6 feet and are adequately sized, you will be fine.  Just be sure to do the "quarter test" and test short out your track at least every 3 feet.  If your booster doesn't shut down when you do this, your wiring is not adequate.

Allan


Allan AE2V
 

I forgot to say, that exactly where you attach the feeder is not critical - as long as you pass the quarter test.

Allan


Jim Betz
 

John,

  *** The following are my opinions - based upon my experiences of converting 3
        separate DC layouts to DCC.  ***

1) If it was a working layout on DC it is probably/possibly good for DCC.  Said another
     way - if you weren't having trouble on DC you probably won't have trouble on DCC -
     with the same wiring.

 2) Exception number 1 - DCC wiring should NOT be common rail.  If you had block
      control on DC then "all" this means is breaking the common rail on the bus
      boundary (boundaries) and adding additional power bus wiring to reach to those
      newly isolated blocks.

  3) Exception number 2 - many DC layouts are wired without good wiring practices.
      If you have feeders crossing block boundaries you are -going to have trouble-
      on DCC.  There is an easy fix for this - while the layout is still on DC power up
      one block at a time and go around and check all the OTHER blocks and see
      that none of them have power.  You will have to do this for each block (power
      the one and test all the rest).  Repetitive but persevere - it's worth it.
         I highly recommend the RRamp meter for this testing - and for DCC testing
      after the conversion is done.

  4) The best layouts (DC or DCC) will have a feeder to every physical piece of
       rail.  Don't trust rail joiners to pass the power between pieces of rail.  Leave
       them in place - just don't rely upon them.  Feeder location - anywhere in the
       maximum 3 feet of rail - is immaterial.  Having rail joiners when the two
       pieces of rail are in the same power block - just acts as redundancy to the
       feeders.

  5) Double gap (that means isolate both rails) at every power block boundary.

  6) Yes, you can run the layout on DC -or- DCC.  As Long As you run the ENTIRE
       layout on one or the other.  To do this it is imperative that you use a DPDT
       with center off selector switch ... if your DCC equipment ever gets connected
       to DC there -will- be damage.  If they are both powered it will get expensive
       very quickly (at the speed of electricity).
         I do NOT recommend trying to set up for both DC and DCC.  In just a couple
       of months of running DCC you will say "that was a waste of time".  My
       recommendation is to disconnect your DC power pack and put it in a box
       in the closet and forget about it.  Yes, this means converting your locos to
       DCC - once you've done 4 or 5 you will be saying "this isn't a big deal"
       (installing decoders).

  7) Establish a wiring color code - and USE IT.

  8) What you wire today - test today.  Don't wire for 2 weeks or more and
       then test.  The idea is to have an ever growing - WORKING - railroad.
       This also helps in terms of when you have a problem you know what
       (where) the problem is - and it is usually only one problem.

  I suspect you are going to have to add some additional feeders.  There is a
tool out there called the IsoTip 8000.  It is a cordless soldering iron.  It works.
Amazingly well - even for soldering feeders to rail.  It has replaceable tips -
get the smallest one and also a wedge shaped one and make your own
decision about which size you prefer.  It's less than $100 on Amazon.
Yes, you still need to use flux and clean the surfaces before you solder.
  The IsoTip is so good I've never had to stop to charge it during a
session.  I'm wiring my layout right now and I typically work in 2 to 4
hour sessions.

  Good luck - you aren't really going to need a lot.  Feel free to contact
me offline if you have questions.
                                                                                    - Jim in the PNW


Jim Betz
 

  ... forgot to add that I use the PSX circuit breakers (DCC ONLY) and love them
      and recommend them.  My personal practice is that "no rail is not protected
      by a PSX breaker" - that means I do not use the circuit breaker built into the
      booster(s).

 ... also - based upon your description you don't need a lot of power.  If it is a
     one or two person layout - you can probably use an NCE PowerCab and
     you won't ever need anything else.
                                                                                         - Jim in the PNW


John DeSantis
 

Thanks for your input Jim. It's greatly appreciated. 

John 



Sent from my Verizon, Samsung Galaxy smartphone


-------- Original message --------
From: Jim Betz <jimbetz@...>
Date: 9/8/22 4:29 PM (GMT-05:00)
To: w4dccqa@groups.io
Subject: Re: [w4dccqa] Feeder connections

  ... forgot to add that I use the PSX circuit breakers (DCC ONLY) and love them
      and recommend them.  My personal practice is that "no rail is not protected
      by a PSX breaker" - that means I do not use the circuit breaker built into the
      booster(s).

 ... also - based upon your description you don't need a lot of power.  If it is a
     one or two person layout - you can probably use an NCE PowerCab and
     you won't ever need anything else.
                                                                                         - Jim in the PNW


Swanny
 

Jim, you have provided the best overview of what should be considered "Best Practices" for converting to DCC or building a DCC railroad!  I have assisted in converting a couple DC railroads to DCC and can absolutely validate every point you make, including not creating DC/DCC capabilities, as it quickly becomes obvious (even to someone with hundreds of locomotives) that DC operation will never really be satisfactory.  With your permission, and of course with attribution, I would like to user your thoughts when communicating with other model railroaders (personal communications, not publication).  I suspect that I'm not alone in my appreciation of your concise penmanship.
Thanks.
John Swanson


Jim Betz
 

Swanny,
  Yes, of course you may pass on the things I said.
                                                                                                  - Jim in the PNW