Trade Practical and Workshop Skills
What is tested
Bench and site skills: correct handling of tools, joint making, conduit work, standard wiring circuits, testing and safe working habits, assessed in the practical examination.
Core skills
Measuring and marking with a steel rule and try square; filing and sawing to a line; drilling and tapping. Bending conduit to 90° with a blow lamp and bending spring, keeping the radius at least 2.5 times the conduit diameter so wires can still be drawn. Joints - western union, married, tee and rat-tail - must be mechanically sound, soldered and insulated with two half-laps of tape.
Wiring practice
Standard boards include one lamp and one switch, the two-way staircase circuit, the godown (corridor) circuit, and a bell circuit with a push button. Test each with a continuity tester before energising.
Worked example
Staircase wiring: feed phase to the common of switch A; run two strappers from A's L1 and L2 to B's L1 and L2; take B's common to the lamp; take the lamp's other terminal to neutral. The earth goes to the metal box, not to a switch terminal. Test with the lamp off: continuity should exist through the strappers and must not exist between phase and neutral.
Safety and housekeeping
Isolate and lock before work, use insulated tools and rubber-soled shoes, keep the bench clear and follow 5S. For electrical fires use CO₂ or dry powder, never water. For electric shock: isolate, call for help, check breathing, begin artificial respiration or CPR.
Traps
Bending conduit without a spring so it kinks; leaving cut strands at terminals; energising before continuity and insulation tests.