Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

CIRCUIT BREAKERS

1376 views
4 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    April 2005
  • 211 posts
CIRCUIT BREAKERS
Posted by mcddhawk4 on Monday, July 28, 2008 11:41 AM
How many circuit breakers can 1 booster handle? I have an 8 amp booster and would like to seperate the layout into 6 districts.
BNSF FAN
  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,336 posts
Posted by MisterBeasley on Monday, July 28, 2008 12:07 PM

A circuit breaker should not use any power at all, although there may be some small amount used for the detection circuitry if it's an electronic one.

You should have no trouble putting a large number of breakers on one booster.  Remember, though, that the tracks protected by each breaker will be limited in power by the breaker, not the booster.  So, if you put a 2-amp breaker on your main line, then you're not going to be able to run 8 amps of trains there.   You can run a total of 8 amps across the layout, but only in 2-amp chunks, if that's the capacity of the breakers.

It takes an iron man to play with a toy iron horse. 

  • Member since
    February 2006
  • From: Gahanna, Ohio
  • 1,987 posts
Posted by jbinkley60 on Tuesday, July 29, 2008 5:21 PM

 mcddhawk4 wrote:
How many circuit breakers can 1 booster handle? I have an 8 amp booster and would like to seperate the layout into 6 districts.

I have 5 breakers off of my 8 amp booster and 3 off of each of my 5 amp boosters.  There really is no limit but the combined load could exceed the total output of the booster (at some point).  However, this is the good point of breaking things up on separate breakers.  I advocate more instead of less, especially if you plan to grow.  It is much easier to add boosters for more power if you've already broken things up than to go back and cut tracks and add additional feeders/buses.   

Ultimately there are two design points.  First the total current draw within a given area cannot exceed the output of the breaker.  Thus smaller areas protected by breakers allows you to feed more power across the layout but also will allow a higher concentration of locomotives.  This is the time when you want to run your 8 mu'd locomotive QSI based sound train along with another 4 unit train in the same protected area.  Second the total current draw through the breakers cannot exceed the output of the booster they are tied to.   The good news here is that the fix is simply a new booster and then move some of the breakers to another booster. 

My layout is 11' x 10' dual level and is wired with 11 power districts and 3 boosters.  Yes, way overkill but I don't want to address this again in the future and I have numerous sound locomotives and often will run a number of them at one time or have a number parked in a yard with the sound going. 

Here's something I found on Tony's website:

http://www.dccspecialties.com/products/pdf/psx_hints.pdf

Why Divide my Layout? (Courtesy of Kalmbach Publications)

Though DCC offers a more realistic type of train control - being able to run multiple locomotives independently on the same track - the electricity running through the rails of your layout still needs to be properly managed and distributed. Since one of the big selling points of DCC is that you don't need to divide your layout into individual electrical blocks for independent train control, you're probably asking yourself, "why should I do it?" In addition to minimizing operating disruptions, power districts are also a key to DCC power regulation. If you're running a lot of trains, you'll need to make sure your DCC system can supply all your power needs efficiently and safely. Adding power districts to your layout can help with that. By separating your layout into districts, you divide the total track power available into smaller, more manageable units.

How do I Determine Power Districts?

There are really two types of power districts: those that are circuit-breaker protected zones on the layout and those that have their own independent Booster (also breaker protected). Probably the best way to determine where to place power districts is to take a look at the expected current draw, (Traffic), for each operating location on the layout. For example, a busy yard might have two switchers, one or more trains on the arrival and departure tracks, another train or two passing the yard on the main, and maybe a peddler working nearby local industries. If some or all of these trains have more than one locomotive, you could have 10 to 15 current-drawing units all competing for power in a fairly small area. Even assuming that the locomotives have efficient motors, this type of load may be heavy enough to slow down a DCC system running on a common 5A booster. Generally, our experience has shown that in HO if you have for a 12-14 Awg buss and 20 Awg feeders, that a 5 Amp system can support up to 10 0perators. Many users overestimate the amount of Booster power needed.

 

Engineer Jeff NS Nut
Visit my layout at: http://www.thebinks.com/trains/

  • Member since
    April 2005
  • 211 posts
Posted by mcddhawk4 on Wednesday, July 30, 2008 4:28 PM
Thanks for the quick replys how many fully equiped loco's (dcc with sound) can be run in each district?
BNSF FAN
  • Member since
    February 2006
  • From: Gahanna, Ohio
  • 1,987 posts
Posted by jbinkley60 on Wednesday, July 30, 2008 7:35 PM

 mcddhawk4 wrote:
Thanks for the quick replys how many fully equiped loco's (dcc with sound) can be run in each district?

Depends upon the trip current on the breaker and the particular sound locomotive.  Some of the older QSI sound locomotives drew quite a bit of current on startup.  I set my PSX trip current for 4.6A and I can safely run around 7-8 of the older QSI units before I reach the limit.  More with some of the newer sound units (i.e New QSI, Soundbug, BLI Blueline etc...)

 

Engineer Jeff NS Nut
Visit my layout at: http://www.thebinks.com/trains/

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!