11

12 a)

0)

13

14 a)

0)

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The plan layout of a one bed room domestic building is shown below. Locate (10)
the light, fan, socket points etc., required for the electrification of the building
as per NEC requirements. Calculate (a) Connected load of the building (b)
Maximum demand in kW (c) Type of supply required (d) Number of light and

power circuits (e) Details of the distribution board selected

Toilet

Dinning room

Drawing room

kitchen

Bed room

PART C
Answer any two full questions, each carries 10 marks.
Which are the main factors to be taken into account for the selection of cables, (5)

Explain

Fault current anticipated in a location is 8000A. soil resistivity = 10 Q-m. Earth (5)
resistance is limited to 1Q. Design an earthing system. Fault duration can be

taken as 3seconds. Plate electrode of 1.2mx1.2mx12.5mm shall be used.

A 400kVA, 11kV/433V delta-star connected transformer is installed in an (10)
industry. This transformer is connected to 11kV supply through an over-head

line of length 2.5 km. The conductor used is RABBIT with an equilateral
spacing of 900 mm. The percentage reactance of the transformer is 4% and the

full load copper loss of the transformer is 2%. The three-phase short circuit
power at the utility substation is 40031۷ 8. The resistance of the line conductor

is 0.454Q/km. Calculate peak short circuit current on the primary and
secondary terminals of the transformer.

Which are the pre-commissioning tests on power transformers used in व (5)
electrical installation. Explain

An outdoor pole mounted 11kV/433 V substation has to be installed for supply (5)
to a residential area having a load of 63 kVA. With the help of a neat diagram,

make a list of materials required.

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