Bus wire

[GBMicros]

If I am using a Hornby Elite controller do I still use a bus wire?

My Layout is 8 feet by 10 feet with two ovals overlapping so one circuit round would be about 45 feet.

I had 1 drop wire from each oval and it worked fine. I have now added two more on the other side of the layout but when I connect the Elite it Errors.

I have checked for continuity with the elite unplugged and get no reading.

If I connect any 1 new set of wires on its own it works fine.

The last edition to my layout was 2 Peco Streamline SL-96. Which I haven’t put the little link wire on them.

Any guidance would be greatly appreciated, I am still new at this as well.

If you need more information please ask.

Thanks Gary

[Chrissaf]

I have now added two more on the other side of the layout but when I connect the Elite it Errors.

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One or other or both of the NEW dropper feeds you have connected are REVERSED causing a 'short'.

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Disconnect both the new dropper feeds, then reattach them 'one at a time'. If attaching the first dropper causes the Elite to error, then reattach the dropper but with the wires reversed. This should allow the Elite error to be cleared. If the error clears, move on to the second new dropper and perform the same process again.

[GBMicros]

OMG. I can’t believe I got the basics wrong. Maybe I should give up now.

I must have checked this at least 3 times to make sure I was the right way round.

Thanks Chrissaf.

[Chrissaf]

It is 'best engineering practice' to attach droppers 'one pair at a time' and test for a short for each newly attached pair. In your case you only had two new dropper pairs to contend with, but what if you had attached 20 dropper pairs and only one of them was reversed. Murphy's law would dictate that it would be the last one of the 20 that you disconnected (to test) that is the reversed one. Shorts are so much harder to find than 'open circuits'.

[GBMicros]

All fixed and working.

Good job I’m better at soldering than Model Railway.

Thanks again Chrissaf.

[2e0dtoeric]

There's a simple way to stop any other newcomer from falling into the same trap.

Having laid the track, and BEFORE any decorating, put a truck on the track, with a RED felt pen taped to one side, and without lifting it off the track, push it all round the railway, tapping the end to put a red dot everywhere you intend putting a dropper. Then do it again with a BLACK (or green/yellow/sky blue pink) pen on the OTHER side of the truck.

Assuming you have colour-coded the BUS wires red and black, and you have used red and black droppers through holes drilled by the red and black dots, it is just a case of matching up colours!

It doesn't hurt to double-check with a multi-meter set to 'continuity', either.

All the 'red dot' track should show a short circuit to the Red bus but an open to the Black one, and vice-versa.

[Chrissaf]

Just be aware that Eric's solution although a well established solution for traditional loop based model railway layouts. Does not work in a foolproof manner when your layout has a WYE or traditional Reverse loop in the design. Sooner or later the left hand side truck colour will meet a rail already marked with a right hand side truck colour.