General requirement of all electrical installation

~ All electrical installations should be in accordance with the Indian Electricity Act and the relevant regulation as per the requirement of the Electricity Supply Authority.  According to IS: 732-1983, all materials, fittings, appliances should be as per Indian standard specification.  If it is not as per the Indian standard specification then it should be validated through the appropriate authority.  Good workmanship and installation must be properly functioning for electrical safety.  is: 732-1983 The installation work is carried out by the State Government under the direct supervision of a person holding a certificate of proper qualification.


* General requirement for layout wiring

In pursuance of IS: 732-1983, the power and heating sub-circuit should be separate and separate from the lighting and fan sub-circuit.  All types of concealed or unconcealed wiring should be easily inspected.  Un-concealed wiring should be close to the ceiling when running along the wall.  Any type of wiring should look visually good.  The load in a three phase installation should have a balance in the three phase circuit.


*  General requirement for conductor

All conductors should be made of aluminum or copper.  When the copper conductor is used for the final sub-circuit its cross-section area should not be less than 1.00 mm… and for the aluminum conductor 15 mm.  Cross-section area of ​​copper conductor for power wiring should not be less than 1.5 mm and 2.50 mm for aluminum conductor.  It should not be used where the use of flexible cable or flexible cord causes mechanical damage to the cable.  Flexible conduits or PVC pipes are used when it is used.


*  General requirement for reception and distribution of main supply

Installation is done in such a way that there are no breaks in the neutral wire.  At the beginning of the wiring the switch is connected to the circuit breaker or the live conductor of the supply main.  All main switches of wiring are of metal clad unclosed or insulated unclosed type and are placed close to the main supply.  According to IS: 732 - 1983) 

Open type switch board is used only in dry and ventilated rooms.

 It is not placed near a storage battery.

 Place a flame or use a fully cloned switchboard where there is explosive dust, moisture or gas in the air.  

The switchboard is not placed above the gas stove or sink or the switchboard is installed 2.5 m above the laundry washing room.

 When the switchboard is installed under the influence of a humid environment in unavoidable circumstances, its outer cover is water proof and has glands provided.  

Metal clad switchgear uses any one of the following ten mounting methods.


*  General requirement for hinged type metal board

Seat metal bosses with a thickness of more than 2 mm are used.  It has a metal cover that can be opened / closed for inspection and repair of wiring.  Inside this metal box is a wooden board for incoming and outgoing cables.  The thickness of this board is not less than 6.5 mm and it is insulated with varnish.  This board is fixed to the wall. 


*  General requirement for arrangement of apparatus on switch board

The equipment is mounted on the switchboard in such a way that the person does not inadvertently touch the live pats when the person is changing the fuse or switch.  Any device must be on the inside of the switchboard.  No fuse body is mounted at a distance of 2.5 cm from the edge of the switchboard.  In addition to the holes in the panel of the switchboard, other new holes are provided at a distance of more than 1.3 cm from the edge of the switchboard.  The switchboard has a barrier of insulating material that cannot absorb moisture and ignite quickly between them so that there is no arc between the live parts (conductors).  All devices in the switchboard are configured in such a way that the wiring connection can be easily traced.  When the switch and fuse are fitted on the same pole, the fuse is arranged in such a way that the fuse does not remain in live condition when the switch is in ‘off condition’.


*  General requirement for single phase supply 

In a single phase supply all loads are in parallel and the voltage across the load is the same.  The feeder cable and installation wiring should be designed in such a way that turning the switch on or off does not affect the load of the system.  Figure 1.8 shows the diagram of a single phase installation, connecting the incoming cable to the supply authority cut-out.  In it the connection of the meter is connected to the main switch-fuse (switch and fuse single unit) of the coffer.

This main switch - fuse is connected to the distribution fuse board on one side.  Switches and fuses are always connected with live or phase wires.  When the fuse is connected to a neutral wire, current is not transmitted due to blowing of the fuse.  So any devices that are connected to this supply line get a supply voltage which is alarming.  It is shocking when a person touches his live part, assuming the supply switch is off because the device is not working or turned on.  Similarly the switch is connected to the neutral circuit and the device does not turn on due to total contact.  At this point it is assumed that the supply is off but the device gets full voltage which is alarming.  The neutral wire of the electrical installation is connected to the substation earthing of the supply authority and has no connection of fuse or switch fuse.  The continuity of the neutral wire is not interrupted by connecting the switch.

The wiring of each sub-circuit is electrically separated from each other, so it means that separate phase and neutral wires are taken from the distribution fuse board for each sub-circuit.  For distribution of light and power sub-circuit as shown in Figure 1.8 the wiring is taken from separate point from the cue board, as shown in Figure 1.9 separate distribution cue board is given for each floor and its wiring is done by giving loop.  If the distribution board of each floor is connected with a loop it is called 'Rising mains' so it can be said that the distribution boards are connected in parallel.  This way the wiring system is economical but all the floor supply is disconnected due to blower of the consumer main switch fuse.


*  General requirement for three phase supply 

Power supply to multi-store bidding and industries is provided by three-phase, 4-wire system. (I) Three-phase motors of the same rating are cheaper than single-phase.  In addition, its efficiency is higher than the power factor (Better) so the industry uses a motor with three phase 415 v, 50 Hz supply instead of a single phase motor.  (2) three  Phase, 4-wire system is more economical than single phase system in multi-store building.  Three Phase, 4 - The load in the wire supply system must have balance in all three phases i.e. the distribution of load should be the same for Phase R and Neutral Phase Y and Neutral and Phase B and Neutral.  Loads do not need to be balanced when industries are provided with three phase supply for three phase motor and load.  Proper distribution of single phase load is done to balance the single phase load relative to the three phase load.

three phase, 4 - wire supply system are supplied in three - phase and single phase supply.  It connects the incoming cable with a triple pole and a neutral cut out (a cut out is an electrical appliance that automatically interrupts when more current passes through a specific current).  The supply authority meter is then connected.  After the connection of the energy meter , the cable is connected to the triple pole and neutral switch fuse.  The Triple Pole and Neutral Switch (TP&N) controls the three Phase Distribution Quiz Board.  Power three phase motors, heating appliances and other three Phase loads are supplied from three Phase Distribution Board.

Red, yellow and blue colors for three phases as well as black conductors for neutral conductors are used when wiring.  When there is a load balance current does not flow from the neutral conductor.  The voltage between any one phase and the neutral point is called the phase voltage e.g.  When the line voltage is 415 the phase voltage is 240

The advantage of this system is that the main use is found when the hot pre 5% distribution takes place in the inkmill canal of 54 boards, so all the boards are used after the main which is centered on the diamond of the distribution board, 

A busbar chamber with a distribution board is used when the load is high.  It involves the connection of the cable from the main switch to the busbar chamber.  Cable connections from the busbar chamber are made to the TP & N use board which controls all outgoing sub-circuits.  This system is used when the number of sub-circuits is high so that all the main sub-feeders can be controlled separately.