Track layout power.

[Bighandz]

If anybody could give me a bit of advice I’d be really grateful.

I am in the process of building a large layout which contains 5 ovals and a number of sidings.

I am using a Select controller with a 4 amp power supply.

because of the size of my layout, would I be better supplying each oval with power as a sort of booster, rather than from just 1 power track?

And now the second part of my question. Such a large layout has a large number of points which also need to be powered from my Select. Would I be better getting a second Select to operate my points or upgrading to the Elite and using Control 1 for locos and Control 2 for points?

I realise this is quite a long question but any advice would be much appreciated. Many thanks.

[Chrissaf]

To a certain extent the size of the layout has no real bearing on the size of the power supply. The current capability of the power supply denotes primarily the number of simultaneous locos being run rather than the size of the track layout. Hornby documentation states that the 4 amp supply is good for about 10 modern locos running simultaneously. Even with five loops It is assumed that you would be unlikely to run 10 trains. Apart from which, the logistics of trying to manage the control of 10 trains or more simultaneously in real time by a single person is going to be a challenge. You would really need an exhibition sized layout before needing to consider the deployment of separate power districts powered via boosters. The one exception to this would be if you were using more than five DCC Concept ADS8SX Accessory Decoders which would equate to controlling 40 solenoid points, because these have very high 'in-rush' charging currents.

With regard the points. You haven't specifically said in detail, but it is assumed that these will be controlled using DCC commands via suitable Accessory Decoders.

The Hornby R8247 Accessory Decoders [A.D] and most (but not all) other brand A.Ds contain CDUs [Capacitor Discharge Unit]. The CDU stores a charge to operate the point solenoid motor.

In the case of the Hornby R8247, the initial charging current is about 100mA with a quiescent current of about 17mA. What this means in English, is that the current drain on the controller power pack is minimal. it is the stored charge in the CDUs that are operating the solenoid point motors, not the current from the controller power pack. Thus, your assumptions about points requiring a second controller just for the points due to power concerns is a bit of a 'red herring' - barring the DCC Concepts ADS8SX comment previously made. There are genuine reasons where a second controller can be used, but this is usually more appropriate to when the layout is being controlled via RailMaster software.

[Bighandz]

Thanks again Chris for your great advice.

Just to make sure I understand fully,

I don’t need to put feeds to each oval. Just ensure that all the connections between track pieces are spot on.

I don’t need to worry about power loss operating my points because the motors (Hornby) use capacitors to do the actual switching.

It doesn’t matter how many points, or other switches, I have, as long as they are all connected to accessory decoder (also Hornby).

Therefore I don’t really need either an additional Select controller or to upgrade to the Elite controller.

Hope I’ve got everything right and thanks again Chris.

[Chrissaf]

Yes that is pretty much correct.

Additional wiring [not boosters] from the same controller TRACK A&B output can be connected to each loop to improve power distribution reliability. Remember that with a DCC layout, ALL the track is live ALL the time. So by providing multiple wiring feeds in parallel from the controller track output to strategic locations on the layout, you can then mitigate any reliance on the points themselves to transfer power from track section to track section. The points electrical reliability being the weak link in the power chain.

Just make sure that none of any multiple parallel power feed wiring are reversed, else you will get an instant short circuit.

[Bighandz]

Thanks again Chris.

At the moment continuity of power is by way of points and it makes sense to have a more certain power supply.

Just to make sure I understand Parallel wiring.

am I right in the following?

I go from Select controller to Power Track 1.

From Power Track 1 to Power Track 2.

From Power Track 2 to Power Track 3.

And so on ensuring I maintain polarity.

Or is it,

Controller to connector block.

Then a feed from the connector block to each Power Track. Again ensuring I keep the correct polarity.

Sorry to be such a dim wit but I would prefer to get this right first time without blowing anything up.

[Chrissaf]

Either would do, but my preference would be for the second option.

[Bighandz]

Cheers Chris.

Thanks for all your help.

[96RAF]

The only real limit you have is the points addressing range of the Select. If you have more than 38 individual points then you run out of addresses - allowable points range is 61 to 99 taking note of Group allocations within that range means you lose out on a couple (compare table of Group vs Port addresses).

Some folk have reported loco hesitation when points are switched using the 1-amp supply, but as one usually operates few points simultaneously then the recharge load on the 4-amp supply is hardly noticeable.

[Bighandz]

Thanks for that 96RAF.

I don’t envisage having 36 points.

And a lot of the ones I will have will be operated as pairs for switching lines.

As I have a four amp power supply I intend to use that regardless so I don’t think I will have any problems.

The main reason for the initial question was that I never feel entirely sure that using points is an ideal way to ensure power to all sections of the track.

But again many thanks to you both for your wonderful help.