track control

[greatwestern]

I am building a N gauge layout and need help.
I have two main outer lines and want to run locos each way.
I have crossover points and need to know if I need to isolate the middle section from each other.
I shall be using Peco insulated points on all the layout.

[Brian]

Hi
If the two lines linked by the crossover points are fed by separate DC controllers then it’s usual to fit 2 Insulated rail joiners in the crossover rails.

[508035]

I know this principle works in OO but not sure about N gauge, that if 2 insulfrog turnouts are being used in a crossover formation from 1 track to another, no extra isolation from each other is required.

Extra isolation in the form of plastic rail joiners is generally only required if using electrofrog turnouts. I only found that out myself in OO as I connected 2 electrofrog code 100 turnouts together and had 2 trains moving while using 1 control dial. The turnouts were immediately seperated, the metal joiners removed and plastic joiners fitted, luckily this solved the problem and I restored individual control to my layout.

Hope this helps.

[RFS]

I know this principle works in OO but not sure about N gauge, that if 2 insulfrog turnouts are being used in a crossover formation from 1 track to another, no extra isolation from each other is required.

As Brian said earlier, if the two tracks are being operated independently, ie each with their own DC controller and power supply, then you must have insulated rail joiners on both rails of the crossover. N gauge is no different to OO gauge in this respect.

[Viscount]

I agree that, for these purposes, N and OO behave in the same way.

I operate twin tracks with independent DC supplies and simply rely on the insulfrogs to isolate the tracks when running both tracks. When running over the crossover, either controller will power the locomotive and traverse from one track to the other. Surely if you isolate both rails on the crossover, you would need to use both controllers to traverse and whilst the locomotive is bridging the isolated rails, the locomotive itself joins the two supplies together.

Perhaps I am misunderstanding the postings about isolating both rails and would be glad of more explanation.

[Steve M]

The trick is to set both DC controllers to the same direction a approximately the same power setting. Any momentary bridge across the isolators is effectively ignored in those circumdtances.
Set them in opposite directions and they won't play well together.

[Walkingthedog]

As Steve says having both rails isolated works perfectly with the controllers set at the same speed and direction. No problem even with very slow running.

[Viscount]

Thanks to both for your replies. I can understand why that would work (i.e. using both controllers). What I cannot understand is why the additional isolation is needed as both sides are isolated by the insulated frogs when the crossover is set to normal running.

[Walkingthedog]

It is possible for an insulated frog to be shorted out accidentally so insulating both rails is just good practice.

[Viscount]

It is possible for an insulated frog to be shorted out accidentally so insulating both rails is just good practice.

Thanks for that; I guess I've just been lucky over the years as never known that to happen. Assuming there are no other connections between the two tracks, the shorting would really need to happen on both frogs at the same time. On my layout, the two DC track supplies are totally independent as they each have their own mains transformer so there is no common reference voltage at all.