Correct Answer - Option 3 : 10 A
The minimum size of conductor used in domestic wiring must not be of a size less than 1/1.12 mm in copper or 1/1.40 mm (1.5 mm) in the aluminum wire.
For domestic subcircuit, the maximum load should not be exceeded beyond 800 W, and the current rating also not exceed beyond 10 A.
For flexible wires, the minimum size is 14/0.193 mm.
The height at which the meter board, the main switchboard is to be fitted 1.5 meters from ground level. The casing will be run at a height of 3.0 meters room ground level.
The light brackets should be fixed at a height of 2 to 2.5 meters from ground level.
The maximum number of points in a subcircuit is 10.
The maximum load in a subcircuit is 800 W.
I.E. Rules regarding power wiring:
- In a power sub-circuit, the load is normally restricted to 3000 watts and a number of outlets to two in each sub-circuit.
- All equipment used in power wiring shall be iron-clad construction and wiring shall be of the armored cable or conduit type.
- The length of flexible conduit used for connections between the terminal boxes of motors and starters, switches, and motors shall not exceed 1.25 meters.
- Every motor regardless of its size shall be provided with a switch fuse placed near it.
The minimum cross-sectional area of the conductor, that can be used for power wiring of 1.5 mm2 for copper conductor cables and 2.50 mm2 for Aluminium conductor cables (refer to ISI recommendations). Hence VIR or PVC cables of size lower than 3/0.915 mm copper or 1/1.80 mm Al can not be used for motor wiring.
- For motors below 15 BHP which have a very heavy starting current, a fuse should be of current rating to carry the starting current of motor safely and cable should be of current rating not lower than half of the current rating of the fuse.