Power control problems

[Robin121]

/media/tinymce_upload/08652090267ab17599c1a860c6804992.jpgI haven't had a Hornby set for 50 years, and I've just set up a OO gauge for my grandson. It's on an 1800 x 1200 board and is basically an outer and inner track connected by two sets of points. I connected an R8250 controller to both the inner and outer track.

At first everything worked fine, beng able to run two engines simultaneously on both tracks, and I could change engines between tracks by switching points.

Now I am getting times when one or both engines won't run or run slowly, and also it appears that R8250s have a safety cutout and time reset if they detect a power supply issue. The problem can be intermittent, and now I'm also having problems even running one engine, as the power cuts when I change the points, even although I have a controller on both tracks.

Can anyone please tell me what I'm doing wrong, although I don't undertsand why it all worked perfectly to begin with?      

[Chrissaf]

You need to electrically isolate the two ovals by fitting Hornby R920 Insulating Rail Joiners at locations indicated below in the image by the red arrows. When either of the two routes indicated by the white lines are set. The inner and outer ovals are electrically in contact. This also means that the two R8250 controller outputs are shorted together in that scenario. This means that the output of the two controllers are electrically fighting each other. This will result in strange loco movement results as you have described depending upon the controller knob position and switch settings. When all the points are set to keep the locos on their respective ovals. The two ovals are electrically isolated. Hornby Insulfrog points (turnouts) act as electrical switches to route track power to the direction they are switched to.

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" I'm also having problems even running one engine, as the power cuts when I change the points, even although I have a controller on both tracks."

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If the two controller outputs are at opposite output polarity on their respective ovals. A short circuit is created when the two ovals are connected together via the points. This causes everything to stop. Fitting the R920 joiners as described will resolve this issue.

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/media/tinymce_upload/275dd56c618cd04d4cb59e1edf2d16ba.jpg

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Want to understand more about wiring up two ovals with two controllers. Then read Section 5 of my downloadable document located in the locked sticky thread at the top of the forum 'General Section' titled "Getting Started with Track Extension Packs".

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As to why it worked initially, Probably just coincidental, that during those early loco movements you were not creating the problem conditions that you are now experiencing as you try out more sophisticated loco movements.

[Chrissaf]

I'm just wondering if Robin is unaware his question got posted, since it would have been held back for image moderation, Therefore bumping post should he return to look for it. Shan't bump a second time though.