Practical Significance
Switch board wiring is very important. Improper connections of neutral and live (phase) wire in a switch board is dangerous and leads to electric shock while maintenance work.
Competency and Practical Skills
This practical is expected to develop the following skills for the industry identified competency: ‘Plan wiring/cabling activities using relevant materials following safe practices’
i. Use colour code in wiring.
ii. Wire up the circuit.
iii. Fix electrical accessories.
iv. Test wiring circuit.
Practical Outcome
1. Prepare switch board containing four switch four socket arrangements (with fuse, indicator, internal wiring etc.).
Relevant Affective domain related Outcome(s)
i. Practice good housekeeping with safety measures.
ii. Demonstrate working as a leader/a team member.
iii. Maintain tools and equipment.
iv. Follow ethical practices.
Minimum Theoretical Background
While specifying the boards for wiring installation, the following particulars shall be given.
1. Material of the board — wood, PVC or metal.
2. Size — length, breadth and height in mm.
3. Thickness of the material in mm.
4. Single or double (double-hinged or non-hinged type).
5. Additional information like type of finish on wooden boards, colour of PVC or metal boards, surface of flush mounting, etc. Now a days wooden or sunmica boards are not used in wiring. Modular metal boards are used in concealed wiring; however PVC modular boards shown in Fig. 1 are used in surface wiring.
Colour identification of cables.
The colour of the cables indicates their function. Every electrician should be able to identify the colour code used in electrical work and follow it meticulously to avoid hazards. Following table gives the colour code and the alpha—numeric notation as recommended by N.E. code.
Alpha-numeric notation and colours
Practical set-up / Circuit diagram / Work Situation
Resources Required
Precautions to be followed
1 Always place fuse in incoming live wire.
2 Switch should be connected in live wire.
3 Always connect a neutral in a socket at our left hand side terminal (Always mentioned on socket).
4 Make sure all connection should be tight.
5 Follow colour code of wires.
Procedure
a. Select proper module board as per requirement. (One module is required for switch, fuse and indicator and two modules are required for 6 A socket outlet).
b. Fix the accessories on the board.
c. Close remaining holes with modular board strips.
d. Measure and cut cables for connections according to requirement. Use the BIS recommended colour code for cable connections with in the board.
e. Wire up the board.
f. Connect the earth wire with socket outlets.
g. Complete the board.
h. Check the connection and approved the board from teacher.
i. Connect upper plate to the box with screws.
j. Test the board with test lamp.