Staircase Wiring Practical
1 Answer
Answer :
Practical Significance
Properly installed electrical wiring provides long service, less maintenance and safety.
Therefore, it is necessary to perform wiring practice.
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. Wire up the circuit.
ii. Perform various types of wiring systems.
iii. Fix electrical accessories.
iv. Test wiring circuit.
Practical Outcome
1. Prepare staircase wiring and test it.
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
In electrical wiring work, the electrician is supplied with a layout of wiring installation and an installation plan initially. On the basis of the layout and installation plan, the electrician should draw the circuit and wiring diagrams before the commencement of work for systematic execution of the work. The terms used in wiring installation drawings are explained below with an example of staircase wiring (one lamp controlled from two different places).
Circuit diagram: Circuit diagram shows the schematic connections of the circuit for a specific task in the simplest form, incorporating the graphical symbols. The purpose of a circuit diagram is to explain the function of the various accessories in the circuit.
Fig.1 shows the wiring diagram. (Controlling a lamp from two different places).
Wiring diagram: This is the diagram in which the position of the components in the diagram bears a resemblance to their actual physical position. The wiring diagram may not have distance marking. Use of the wiring diagram along with the layout diagram enables the technician in the initial stages of the planning to specify/estimate the required type, size and length of the cables, and also to decide on the vertical, horizontal and ceiling runs of the cable. The wiring diagram is of great use to test and rectify faults in the installation during maintenance work. Fig.4 also shows the wiring diagram. (Controlling a lamp from two different places with their actual locations.) For his own good and to facilitate quick location of faults at a later stage, the customer should insist on the electrician giving him a copy of the wiring diagram soon after the completion of wiring. The electrician should make it a point to do so.
Layout diagram: The layout diagram shown in fig.3 is a simplified version of the wiring diagram. Its purpose is to inform the reader quickly and exactly, what the circuit is designed for without giving any information on the circuit itself. This type of layout diagram is used for preparing architectural diagrams, plans, etc. of a building. In a layout diagram, it is necessary to indicate with symbols details like whether the wiring is on the surface or concealed, and the run ‘up’ or ‘down’, the number of wires in run, dimensions, and accessories with appropriate 1.8. Symbols. Normally the layout plan is drawn and then the wiring diagram. After completion of the wiring diagram, the numbers of cables to be run in each cable run and the size of conduit or batten are estimated. With the help of the distance marking in the layout plan, the estimation of cables could be made.
Practical set-up / Circuit diagram / Work Situation
Resources Required
Precautions to be followed
1 Mark layout on wiring board before fixing conduit.
2 Make sure all connection should be tight.
Procedure
1. Mark the layout on the wiring board.
2. Cut the PVC pipes as per the layout.
3. Fix the saddles as per the layout and installation plan. (For this work fix the saddle at a distance of 75 mm from the center of the block and conduit accessories. Fix only one side of the saddle initially. The other side is to be fixed while laying the conduit).
4. Fix the conduits and accessories on the wiring board with the help of saddles as per the plan.
5. Cut the cables according to the route and bunch them (Leave the excess length of 200 to 300 mm in each cable for termination).
6. Insert the required cables in the appropriate pipes and accessories as per layout and push the wires to the other end of the pipes.
7. Take the modular boxes. Place them at the conduit ends and mark the external diameter of the conduit pipe on the surface.
8. Cut the upper side of modular box by Hacksaw and remove the portion from it.
9. Prepare round hole for conduit. Check the fitting of the conduit pipe in the hole at intervals till a correct fitting is made.
10. Position the accessories on the top cover of modular box close the open holes with strips (if any).
11. Prepare the end termination of the cables as per the wiring diagram.
12. Insert the lamp cables through the cable entry holes of junction box.
13. Terminate the cables in the batten holders and fix them.
14. Terminate the cables of the switches in the switch, and fix them.
15. Fix the boxes of the switches with wood screw on the wiring board.
16. Connect the supply wires in the supply terminals available.
17. Test the circuit after approval by the teacher.