House Wiring PDF

House wiring ( rules & fitting) Explain House wiring and the important factors related to it: It is a type of wiring which is commonly installed inside a building, house or a shop is called house wiring. Factors that need to be considered about house wiring. Type of load connected and required in a...

House wiring ( rules & fitting) Explain House wiring and the important factors related to it: It is a type of wiring which is commonly installed inside a building, house or a shop is called house wiring. Factors that need to be considered about house wiring. Type of load connected and required in a building. Supply voltage (single phase, three phase). Protection gear/equipment for wiring. Lifespan of wiring to be considered. Atmosphere type. Safety from fire hazard. Attractiveness and design/layout of wiring. Future modification proof wiring. Maintenance - repair and its cost. Explain Cleat wiring. This type of wiring is very cheap and cost effective. It is easy to be installed and hence requires less time to get installed. It has two parts namely a top and a base made of china clay. The base is mounted on a wall and then fixed with screws, then the wires are stretched and fixed in the gaps provided on the base. After the wires are placed inside the gaps firmly it is covered with the top with a screw. Clits come in different variation for eg a 2 wire mountable clit and a 3 wire mountable clit. During installation each clit is placed at a distance of 6 to 8 inches for each other. The life span of clit wiring is 5 years. Advantages: No need of skilled workers. Wiring is very cheap and economical. Faults may be repaired very easily. Dis-advantages: Requires more maintenance. The wiring is not attractive. Wiring is affected by atmospheric changes. CTS wiring (cab tyre sheath): Teak wood is used as base material in this wiring. In this wiring blocks of teak wood are placed and installed on the surface where the wiring is to be installed with the help of screws. To hold the wires, flexible metal clips are fitted with a suitable sized nail. The wire is put over the metal clips and then interlocked by the clips which hold the wires firmly. Advantages: Looks attractive and has durability. Has long life. Faults may be repairable easily. Dis-advantages. Has less mechanical protection. Wiring is affected by atmospheric changes. Requires maintenance. Casing-capping wiring: (pvc wiring - poly vinyl chloride) During earlier days teak wood strip was used for casing capping. As we advanced we started using P.V.C which has a tray to hold the wires and a capping is used to cover it very firmly. According to the plans a layout line is drawn roughly on the wall surface where the casing capping is to be done. Then we drill holes at a distance and insert rawal plugs in it. Then the cassing is installed over the rawal plugs and fixed with the help of screws of the size of 25x8. wires are then placed as per the needs and requirement and then closed by the outer covering called capping. While doing this type of wiring holders, ceiling rose is fixed on a PVC square bolck. Advantages: This wiring is attractive to look at. Is is best suitable against humid and wet environments. Faults are easy to find and repair. Does not Requires much efforts and skills to install. Finding faults and repairing them is very easy Dis-advantages. This wiring method is little costly. Conduit wiring: This method is the most safest wiring method, especially where 3 phase supply is required, we use this type of wiring. Is is mostly used in industries. Workshops, godowns, cinema houses ans public places. There are two types of conduit wiring. 1) P.V.C conduit wiring: there are 3 types of PVC conduit wiring.low gauge, medium gauge and heavy gauge. Round pipe is used to protect the wires, this type of wiring is used in the various houses and public places. This wire is not veery costly. 2) Metal conduit: there are 2 types of metal conduit wiring. Low gauge and heavy gauge. The pipes used in the low gauge are made of thin iron sheets.heavy gauge wiring is made up of thick iron steel. Other parts of the metal conduit wiring are (T), elbow, bend, junction block socket etc. Conduit wiring can be installed on the ceiling or wall depending upon the layout. Advantages: This method is very strong and long lasting. This method can provide protection from water, air and fire to a certain extent. Has long lasting life. Less maintenance and repair work required. Disadvantages: This method is costly. Requires trained professional and highly skilled workers. it is difficult to add or remove any wires once installed. It is difficult to find faults. Concealed wiring: This method is used almost everywhere. It makes rooms look attractive, this method is used in buildings and bangalows. In this method the wiring is done inside of a wall and its accessories like switch boards and holders are mounted on the wall surface. Heavy duty piping is done on the roof before the construction of slab takes place. After at walls are built the piping, junction blocks and boards are installed. While doing the piping a G.I wire is put inside it. This method is just like conduit wiring but the difference is only that the concealed wiring is hidden inside the walls. Advantages: This method is very safe. This wiring method is very strong and long lasting. Buildings and room interiors look very pleasant and attractive. Dis-advantages: Maintenance is very low. Faults are difficult to find and repair. In this method the position of the light fixtures and switch board cannot be shifted and the wiring cannot be increased too. Comparison table of different types of wiring. Sr. properties cleat C.t.s P.v.c conduit Concealed no 1 Life less medium long Very Very long long 2 Mechanical no no good Very excellent strength good 3 cost cheap medium medium costly Very costly 4 Fire no no good good excellent protection 5 Humidity no less good good excellent protection 6 Skilled no yes yes yes yes workers 7 attractiveness less medium good good excellent 8 Maintenance low low low medium high cost What are the different types of Indian electricity rules (IE)  According to the Indian electricity rules, the first rule is a single sub circuit should not have connected load more than 800 Watts and the points should not exceed more than 10 points.  A power board sub circuit should not have load more than 2000 Watts or 2 points.  The current rating on the main switch or distribution box must be decided according to the load.  All the wires used for the wiring must be fire and chemical proof and if the wires have a metal covering then the covering must be provided with earthing.  The earth point on a 3 pin socket should be connected to earthing.  All types metal covers like - main switch, cover, pipe, fan etc should be earthed.  Switch or fuse should not be used for earth conductors.  Live wire / phase wire should always be taken through a connected fuse of any other circuit breaker towards the load.  The switch board should always be located at the left side of the door at 1.5 meter height.  The fan and light points should be at the height of 2.75 meters and 2.5 meters.  Every sub circuit must be connected to distribution box through fuse.  Light point circuit and fan point circuit should be different.  In case of 3 phase 4 wire ( 3 wires of 3 phases and 1 neutral wire) system, there must be an uniform load on every phase, the wires of the 3 phase supply should be only red (R), yellow (Y), blue (B) and neutral wire should be black in color strictly.  Megger test is compulsory once the wiring is completed.  It is mandatory and compulsory to display “DANGER” on the boards if the voltage supply exceeds 250 volts. Sr No Wiring method Materials required 1 Cleat wiring 2 way cleat, 3 way cleat. Round block, P.V.C wire 2 C.T.S wiring Teak wood batton, metal clips, C.T.S wire. 3 P.V.C casing capping Casing capping, square block, P.V.C block 4 Conduit 1way, 2 way, 3 way, 4 way junction block, bend, T, elbow, saddle, clamp, P.V.C / metal pipe, wire. 5 Concealed 1way, 2 way, 3 way, 4 way junction block, bend, T, elbow, saddle, clamp, P.V.C pipe, wire.