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I had envisaged eventually using 4 or more controllers on my layout which is currently at "phase 1", probably 2 or 3 twin-track controllers (3 may well be overkill). Power is fed to the track via conventional section switches and back via common return wiring. However, I have just read the following in a Gaugemaster leaflet " do not connect together two or more control units in parallel i.e outputs linked. If done, there is a risk of electric shock from a plug not inserted in a socket."
Questions ...
1. Does linking the common returns constitute linking outputs as above ?
2. If it does, I can think of a simple way of taping the 2 or 3 13 amp plugs into an extension cable giving a single 13 amp plug for the power. Is this ok ?

Geoff

What you have read refers to what can occurr if you were to connect the AC (alternating current) outputs from 2 contollers (both wires) directly together.
i.e. the output from one can feed AC into the other and the transformer not plugged in can convert the low voltage back into mains power that would appear on the 3 pin plug.
Obviously if you were to then get hold of the plug you could get a hefty shock.

However the use of a common return only connects one wire from each controller so the situation above won't arise.
In addition the outputs to the track are DC (direct current) and DC will not pass through a transformer so again the problem will not arise.

The use of common return is a standard practice on all the layouts of the Heywood Model Railway Group and im pretty sure that it is on most club layouts.

One thing I always do on any control panels that I build for the club is to use a car stop and tail lamp (both fillaments in parallel) wired between the transformer output and the actual controller.
This serves 2 puposes.
1. It limits the current flow so prevents damage to the transformer and wiring should a short circuit fault occur on your layout.
2. Gives a visual indication as the bulb will light up should a fault develop.

Hope that solves your dilemma