Proprietary systems

A number of proprietary systems of wiring have been introduced in the last few years.
Some of these are intended specifically for use with particular methods of industrialized
building, while others are intended to industrialize the wiring operation independently of
the building method so that they should be equally useful for all methods of building.
One of the latter is the Simplex PVC System.
This consists of ordinary PVC insulated cables drawn into a PVC conduit of oval
section. The circuit protective conductor is moulded in with the conduit, as can be seen
from Figure 3.17. Each of the other cables has its own passageway within the conduit.
The conduit itself is made from a flexible