Electric Wiring, 3rd Edition

Mineral-insulated copper-sheathed wiring system 11 3

PVC-sheathed cables running along walls may be buried direct in the

plaster but it is preferable, and involves very little extra cost, to protect them

by means of metal or P VC conduit or channelling. This gives some protection

against nails driven into the wall and, in the case of conduit, permits the

cables to be withdrawn or replaced at a later date.

Accessories used with PVC-sheathed cables are usually of the insulated

type;

however metal boxes can be used at outlet points if desired, provided

suitable grommets or brass bushes are fitted where the cables enter the boxes.

Fig. 7.4 show ...