J&C Studios O Gauge Archive

O Gauge / O Scale Forums and Individual Blogs for Model Railroading

What is the J&C Studios O Gauge Archive?     Need help? support@jcstudiosinc.com

Need Help?
Try watching some of our videos:

(Guest)    J&C Studios O Gauge Archive    Electronics & Wiring    Bus bar for common connections.
This topic is also posted here:
Topic: Bus bar for common connections.
Share & "Like" This Topic on Facebook!
Dale H
Joined: Sep 25, 2010
Topics: 32   Replies: 39
posted on Nov 16, 2010 10:52 PM:
My Archive Category  

Instead of running individual 2 wire circuits throughout the layout a common bus can be used where multiple transformers can use the same feed for a common return. Thus all transformer commons can go to one feed or bus. On a PWZW that would be the U terminal. Even one lead of a DC transformer can share the common. Phasing is not an issue unless the individual transformers are put in parallel. This simplifies wiring as it eliminates the need for multiple 2 wire feeds. Instead we have 1 big feed which can be tapped from various locations on the layout. One application of this is your automobile. The metal body is used as a common so only the hot wire is required to a light bulb for example. The bulb socket can be common with the body providing a return for the circuit. The common on a car body can also be called the ground,not to be confused with earth ground. Because the body is on rubber mounts a grounding strap connects the body to the motor and battery.

Back to trains,it is easy to make a common feed out of bus bar terminal strips called grounding bar extensions sold at home centers for various electrical service boxes. Romex can be used and connected in a loop with the bus bar for screw connections put in convenient locations along the layout. The wire bus must carry the sum of all the amperage of all the transformers hooked to it. 6 , 10 amp Lionel bricks for example would require 60 amps capacity. 3, 12 gauge wire would provide an ample return. So 12-2 Romex could be used. Stranded wire can easily be connected to the bus bar. Here is a picture of it in use. 6 Lionel bricks are hooked to it for 6 separate loops of track. The green wires are commons from the track outer rails.

The bars can be cut to length as needed and screwed to the layout underneath. Hook all transformer commons to it at any point in the loop. Looping bus in a complete circle decreases resistance and voltage drop. This arrangement is not recommended for DCS track wiring.

Dale H



Mr Milepost 12
Joined: Nov 9, 2008
Topics: 27   Replies: 13
posted on Nov 17, 2010 08:22 AM:
My Archive Category  
My Website  

Great deal Dale ! I actually been using this technigue since the 1970's since my former HO layout. It is a great, simple and cheap way to wire. And I also use it for my accessories and lighting. You can make the lighting into "grids" like the power company for easy maintenance.

They also worked inexpensively for hooking up modules on a modular style layout. A very cheap way to "bridge" them together.


Joined: Jul 15, 2010
Topics: 0   Replies: 2
posted on Oct 15, 2011 07:19 AM:
My Archive Category  

Dale, what is meant by 'transformers in parallel'? ralph


Dale H
Joined: Sep 25, 2010
Topics: 32   Replies: 39
posted on Oct 15, 2011 02:19 PM:
My Archive Category  

Whenever the hots and commons of 2 transformers are connected. For example A and U on 1 ZW and A and U on another ZW. This can happen for example if 2 adjacent blocks are powered by different transformers and are bridged by a car with 2 pickup rollers jumping the fiber pin isolating the center rail blocks via the 22 gauge wire connecting the rollers.. Some people also connect to like transformers in parallel to provide more power to a circuit. For example 2, 10 amp lionel bricks in parallel could provide 20 amps to one circuit. In command where multiple trains are run on a large loop this extra power may be needed. If doing this make sure the wiring is of sufficient gauge to carry the amperage, Just sharing a common is not an issue as far as phasing is concerned.


© Copyright 2007-2019 J&C Studios, Inc. All rights reserved.
View our Privacy Policy   Use of this website constitutes acceptance of the Terms and Conditions
The J&C Studios O Gauge Archive is built using POJO Jenerator   Site Map