Building Electrification lab Manual Exp No 6 Sl. No. 4 Surface conduit wiring system

 

 

Department of Electrical Engineering

Subject: Building Electrification Laboratory

By: Palash Das

Lecturer in Electrical Engineering

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Experiment Name: Prepare wiring installation on a board from the commencement of supply showing energy meter, MCB, control of one lamp, one fan and one socket from one switch board in PVC surface conduit wiring system.

 

Number of Experiment: 02; Sl. No 4

Date of Experiment: 

Date of Submission:

Aim: ✓✓To prepare energy meter  connection with load points and to describe conduit wiring.

         ✓✓To Prepare wiring installation on a board from the commencement of supply showing energy meter, MCB, control of one lamp, one fan and one socket from one switch board in PVC surface conduit wiring system

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Theory:

This is a most useful wiring  system for domestic and other purpose. This circuit board  consists of energy meter, MCB, light switch, fan switch and socket and socket switch. Here Output of energy meter, MCB and all switches  are in  series with phase of the supply and all loads are connected in parallel with the supply.

Surface conduit wiring is a general method of electrical wiring where the conduits are mounted on the surface of walls or ceilings instead of being implanted within them. This type of wiring is often chosen for its flexibility, ease of installation, and the capability to modify or expand the electrical system without important disruption. This comprehensive guide will explore the machineries, installation process, compensations and safety considerations associated with this.

All the components are in a switch board and here wiring is surface conduit type.

 Conduit Wiring: Conduit wiring system is the best system of wiring from many points of view. It can be used for surface wiring and also for recessed or concealed wiring. In this system P. V.C. single core cables are drawn through mild steel (m.s.) or rigid non-metallic (P. V.C.) conduit. Conduits are generally erected first and wiring is done later. There are three methods by means of which the wiring of conduits can be done. They are: (a) threading through (b) pushing in and (c) drawing in. Drawing system is commonly used. A.G.I. fish wire is placed in the conduit for this purpose. According to I.E. Rules, for medium voltage supply, all conductors (other than those of overhead lines) shall be completely enclosed in a mechanically strong metal casing or metallic covering which is electrically and mechanically continuous and adequately protected against mechanical damage, provided that rigid non-metallic conduit conforming to IS: 2509 may also be used.]]

According to ISS Indian Standard System (ISS) the minimum size of earth continuity wire is 2.5 sq mm. Cable size should be 250 volt.

 

 

 

 

Circuit diagram:

 

 

 

 

 

 

 

 

 

 

 

Give a image of this system captured by your camera.

তোমার ক্যামেরা থেকে তোলা এই সিস্টেমেরএকটি ছবি এখানে সংযুক্ত কর।

Specification:

Sl. No	Component used	No of component	Rating	Price/piece
1	MCB	1
2	Switch	3
3	Socket	1
4	Indicator
5	PVC board	1	Write the dimensions Length= Width=
6	Connecting wire

 

Required instrument:

1.       Line tester

2.       Screw driver- write it’s dimension

3.       Poker.

4.       Cutter cum stripper

5.       Self adjustable stripper  cutter.

Precaution:

       √√Connect  the circuit as directed by the guide

 

√√ Used predefined wire size  for the assigned load.

√√Earting connection should be used for load starting from energy meter.

√√For light, fan and heating loads the fuse (MCB) rating is not to be less than the total load currents of the circuit.

√√Minimum size of Conduit should be of 16  mm dia.

√√The admissible size of cable as specified by ISS  is 1.5 sq  mm [ 3/ 0.737 mm copper or 1/1.4 mm al conductor. No conductor of smaller section than 1.5 sq mm is to be used for any writing  purpose.

 

 

Conclusion:

 

 

 

 

 

 

 

 

 

Question answer:.

1.  What is the meaning of MCB and it’s minimum rating?

√√Ans- 

2.What is the minimum current  rating of cable?

√√Ans- 1.5 sq mm is admissible 

3.Why earthing continuity wire is necessary?

 √√Ans-For safety and protection. Explain it.

   4. What is the voltage rating of low voltage cable?n

√√√Ans- 250 volt.

  5. How many types of coil are in a energy meter?A

√√√Ans- Two type. C. C and P. C.

  6.  What are the current rating of socket used for light circuit and power circuit?n

√√Ans-15 amp for power circuit.  

    7. What is the rating of a SDB w.r.t watts and  load points?t

√√√ Ans -It is restricted that 800 watts and 10 points. 

   8. What is the minimum height of main switch and other switches i.e SDB  from floor?

√√√ Ans- 1.5m 

   9. What are  the height of  lamp and ceiling fan for any domestic installations?

√√√Ans-2.5m and 2.75m. 

   10.  What is the minimum insulation resistance of domestic installation?

√√√ Ans- 1Mega ohm.

  11.  What is the desirable voltage rating of a meggar used to test insulation resistance for domestic purpose ?

√√ Ans- 500 volt. And used at least for 1 minute.