Re: new dcc HO layout

Mark Gurries

Although it is true that if you have 2 Five amp boosters the simple math says they add up to 10amps.  However that is not what happens electrically.

That simplistic math ASSUMES the booster are wire in parallel and share the load such that together they can provide up to 10amps to a single locomotive.

Booster are use to DIVIDE up the layout electrically into to independent 5 amps sections for many electrical reasons.  Boosters are meant to be “distribute" power around the layout. 

1) Two much power consumed in a geographical are of a multilevel layout.   Example a Engine facility and yard on level 1 and staging track above it on level 2.
2) Long Track bus runs well exceeding ~30 foot run length from the booster.

It is a "divided and conquer” electrical solution to large scale DCC electrical problems.  Cuts them down to manageable sizes.

The electrical division of layout creates what is called a Booster Districts such that a given booster does not share track power responsibilities with other boosters.  As a engine travels around the layout, it only powered by one booster at any time.  Hence even if you have two 5amps boosters, the engine only receives a maximum of 5amps of power from one of them at any time.    The only time the two booster come into electrical contact with each other is when a given engine cross the booster district boundary consisting or two double insulated rail joiners or gaps.  When the engine completes the crossing, it back to a single booster for its power source.

Booster districts are not to be confused with power districts.   Power districts are created by some kind of DCC circuit breaker that runs from a single booster.  So each booster can have its own independent set of power districts subdividing it power.

So having two 5 amp booster does not make it a 10amp booster layout.  It is still a 5amp booster layout just divided up into multiple 5A sections.

The only time you would need high current 8 to 10 amp boosters is if you have large scale locomotives such as O scale or G scale where the engines NEED that kind of power within a booster district.  But the rules of how many booster you need remains the same as above.

On Jan 7, 2018, at 11:34 AM, Affordable Roofing Contractors vmarino2009@... [WiringForDCC] <WiringForDCC@...> wrote:

Hi Ed, 

the pro cab r has a 5amp control station and the pb5 power booster is also 5amps. Doesn't that provide a total of 10 amps or am I missing something?  Yes I want the capacity to run >10 loco without a power deficiency. 

What exactly do you mean "Also the cases of the boosters need to be bonded together."?


Vincent Marino 
Vincent Marino
Affordable Roofing Contractors
Project Manager
904-260-7663 office
904-683-2914 fax
904-449-6339  mobile  
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On Sun, Jan 7, 2018 at 2:22 PM, 'Ed Sargent' ed_sargent@... [WiringForDCC] <WiringForDCC@...> wrote:

If I’m following this correctly but if you separate the layout into power districts 5 amps are plenty unless you plan on having 10 engine consists. I have seen 9 engine consists pulling 140 cars using PB5s. Also unless I’m miss understanding 2 boosters don’t give you 10 amps. Also the cases of the boosters need to be bonded together.


From: WiringForDCC@... [] 
Sent: Sunday, January 7, 2018 11:33 AM
To: WiringForDCC@...
Subject: Re: [WiringForDCC] Re: new dcc HO layout




I'm not an NCE user, but here goes.  If you have two devices, each of which can provide 5 Amps to power your trains, you may not merge the DCS and DB booster outputs before splitting off to the various blocks.   You'll damage the booster or the command station, or both.  They need to be kept completely separate all the way to the rails; this is the same whether you're using NCE, or Digitrax.  It's the same as having two power amplifiers for your stereo - you can't just tie the outputs together and get twice as much wattage.  

As for the buzzer, what powers it?  Again, you should get in the habit of not wiring any energized item to your rails, so if you're going to use a buzzer to monitor for shorts, make sure you disconnect the DB/DCS before you start wiring..
Blair Smith

On 2018-01-06 16:34, Affordable Roofing Contractors vmarino2009@... [WiringForDCC] wrote:

Don thanks for the advice. Yes I purchased the PH-PRO-R it comes with the command station integrated with a 5 amp power station, UTP panel and cables. Additionally, I purchase a separate power supply for the pro cab.  I also purchased a separate PB-5 amp booster that will give me a total 10 amps so I can run up to 10 loco. 


The wiring of the pro cab and pb5 is my next challenge. I'm thinking they can both go into a wire terminal that separates into power sections. Or does the pro cab power station daisy chain into the pb5 then to the wire terminal?  That's what I need to find out.. 


I'm going to take your advice and leave the circuit breakers off for the time being.  I purchased a buzzer that I will use when installing the track. I understand it will buzz if I install a feeder wire wrong..  


I am so new to DCC but very excited about the challenges and rewards. I appreciate your input.  

Vincent Marino 
Vincent Marino
Affordable Roofing Contractors

Project Manager
904-260-7663 office



Best Regards,

Mark Gurries
Electrical Engineer
DCC Website & NMRA DCC Clinics:

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