Well as you say from the Vid it does work and was under DCC (LGB (P)) Control. Only one part of the Triangle is affected by the effect of a Train creating a short by changing Polarity (not the right word as this is AC) on the one section. A reverse loop would be similar.
You should note that though all the wiring is on the section that would cause the short there is an Isolation Section and the Track Feed to the unit is taken from the LEFT of the first one, thus not being in the "Change" section. The Change Track feed are the two Right wires. This is the same setup as in Aurthurs Scematic in Post #19 except that mine is on a Y or Triangle, but basically the issue and solution is just the same. My feed to the Controller (CS3 in Arthurs diagram) was by the Control Unit on my Vid.
As the Loco trundles around the loop you can hear the Relay Click as it passes over the first Isolation and again as it passes over the second one. This is the internal relay inside the unit fliping the Polarity or Outside Rail Feed (blue) inside Feed (red) over. Whilst on the isolated section the loco does not care if it gets the Outside or inside feeds flipped, it does matter tjough as it goes across the isolation which is why the relay trips them over as soon as it detects a Short.
Hope this helps.
JonD
