Installation Practice and Workmanship
Core concepts
Good workmanship is assessed as much as knowledge. You need to know how cables are supported, protected against mechanical damage, and kept clear of heat sources and sharp edges. Understand bending radii, the need for grommets where cables pass through metal, and correct methods for terminating conductors in accessories. Know how to run cables in walls, ceilings and buried ducts, and the requirements for separation of power and communication cables. Earthing continuity of metal enclosures, correct polarity at accessories, and secure fixing of boxes and fittings are all examinable.
Traps
Questions frequently present a poor practice and ask what is wrong: cable run diagonally in a wall without a safe zone, unsheathed cable in a damp location, or a joint hidden behind plaster. Another trap is confusing 'supported' with 'clipped at regular intervals' - the spacing matters. Watch for questions about cable entry into metal enclosures without protection.
Worked example
A cable is to pass through a metal back box. The correct practice is to fit a rubber or plastic grommet, or use a cable gland, so the sheath is not cut by the metal edge. If a question shows a bare cable passing through a drilled hole in a metal stud, the answer is that mechanical protection is missing.
Rule of thumb
If a cable can move, be cut, or be reached by water or heat, it needs support or protection - ask yourself which one is missing.