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General Rules For Wiring

The general rules, which are to be kept in mind in execution of internal wiring work, are:

1.    Every installation is to be properly protected near the point of entry of supply cables by a two-pole linked main switch and a fuse unit. In a two-wire installation if one pole is permanently earthed, no fuse, switch or circuit breaker is to be inserted this pole. A 3-pole switch and fuse unit is to be used in 3-phase supply.

2.    The conductor used is to be of such a size that it may carry load current safely.

3.    The conductors installed are to be safe in all respects.

4.    Every sub-circuit is to be connected to a distribution fuse board.

5.    Every line (phase or positive) is to be protected by a fuse of suitable rating as per requirements.

6.    A switch board is to be installed so that its bottom lies 1-25 metres above the floor.

7.    (a) All plugs and socket-outlets are to be f 3-pin type, the appropriate pin of socket being connected permanently to the earthing system.

(b)Adequate number of socket-outlets is to be provided at suitable places in all rooms so as to avoid use of long lengths of flexible cords.

(c)Only 3-pin, 5 A socket-outlets are to be used in all light and fan sub-circuits and only 3-pin, 15 A socket-outlets are to be used in all power sub-circuits. All socket outlets are to be controlled by individual switches, which are to be located immediately adjacent to it. For 5 A socket-outlets, if installed at a height of 25 cm above the floor level, the switch may, if desired, be installed at a height 1-30 metres above the floor level. In situations where a socket-outlet is accessible to children, it is recommended to use shuttered or interlocked socket outlets.

(d) In case an appliance requiring the use of a socket outlet of rating higher than 15 A is to be used, it is to be connected through a double pole witch of appropriate rating. In no case a socket-outlet of rating higher than 15 A is to be installed.

(e) Socket-outlets are not to be located centrally behind the appliances with which these are used. Socket-outlets are to be installed either 25 cm or 1.30 metres above the floor level as desired.

(f) No socket-outlet is to be provided the bath room at a height less than 1.30 metres.

(g) Depending on the size of the kitchen, one or two 3-pin 15 A socket-outlets are to be provided to plut-in hot plates and other appliances. Dining rooms, bed rooms, living rooms, and study rooms, if required, each is to be provided with at least one 3-pin, 15 A socket-outlet.

8.    (a) All incandescent lamps unless otherwise required, are to be hung at a height of 2.5 metres above the floor level.
(b) Unless otherwise specified, all ceiling fans are to be hung 2.75 metres above the floor.

9. (a) Lights and fans may be wired on a common circuit. Each sub-circuit is not to have more than a total of ten points of lights, fans and socket outlets. The load on each sub-circuit is to be restricted to 800 watts. If a separate circuit is installed for fans only, the number of fans in that circuit is not to exceed ten.

(b) The load on each power sub-circuit is to be normally restricted to 3,000 watts. In no case more than two outlets are to be in a power sub-circuit.

10.    No fuse and switch is to be provided in earthed conductor.

11.    Every circuit or apparatus is to be provided with a separate means of isolation such as a switch.

12.    All apparatus requiring attention are to be provided with means of access to it.

13.    In any building, light and fan wiring and power wiring are to be kept separate.

14.    In 3-phase, 4-wire installation the load is to be distributed equally on all the phases.

15.    No additional load is to be connected to an existing installation unless it ahs been ascertained that the installation can safely carry the additional load and that the earthling arrangements are adequate.

16.    Lamp holders used in bath rooms are to be constructed or shrouded in insulating materials and fitted with protective shield and earth continuity conductor is not to be of size less than 7/0.915 mm.
17.    The metal sheaths or conduits for all wiring and metal coverings of all consuming apparatus or appliances is to be properly earthed in order to avoid danger from electrical shock due to leakage or failure of insulation.

18.    Each sub-circuit is to be protected against excessive current (that may occur either due to overload or due to failure of insulation) by fuse or automatic circuit breaker.

19.    All live conductors are to be insulated or otherwise safe guarded to avoid danger.

20.    After completion of work the installation is to be tested before energisation

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