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(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

Solve any one question from Q.1(a) & Q.1(b)
1(a) Design & draw the developed double layer lap winding of DC armature with 24 conductors and 4 poles. Also show the direction current in the coils and brush position. Draw the sequenc diagram.
30 M
1(b) Draw the developed winding diagram for an AC machine with following details:
a) Speed = 3000rpm
b) no of slots = 24
c) Frequency = 50 Hz
d) Phase = 3 short pitch by 5/6 double layer lap and star connected.
30 M

2 Draw a single line diagram of a typical substation:
Transformers: -2, 5MV, 66/11KV, delta/delta, 3phase, 50HZ.
Auxiliary tranformer: -1, 11KV/400V, delta/star, 3phase, 50 HZ.
Incoming lines: -2, 66KV Outgoing lines: -1, 66KV outgoing lines: -5, 11KV
66KV and 11 KV buses are double bus with a bus coupler
Coupling condenser, wave trap, earthing switches, are to positioned at the incoming lines. Indicate the positions of CT, PT, isolating switches and lighting arrestors.
20 M

3 The following are the details of three phase core type Transformer. Draw to a suitable scale.
a. Elevation of the 3 transformer assembly showing one limb in section
b. Plan of Transformer assembly showing one limb in section
Core: Step construction, Core diameter = 220mm, Height of the core = 480mm, Height of the yoke = 250mm, Center to Center distance between the limbs = 350mm
LV winding:
Inside diameter = 231 mm
Winding is two layer total radial former = 13.3 mm
Radial thickness of one layer = 7.4mm
Thickness of LV former = 3mm
Number of turns/layer = 13
Total height of LV Winding = 427mm
HV winding:
Outside diameter = 340mm
Total number of coils = 12
a. Two coils of end gun metal ring each of 14mm thickness
b. Ten coils of 56 turns each,
Total height of winding = 427mm,
Average and clearance 33mm from top and 200mm from bottom of the yoke.
50 M

4 Draw to a suitable scale end and longitudinal elevation (top half in section) of a 100 KW, 500V, 1250 R.P,P 6 pole DC shunt generator. The armature is supported over the spider and the shaft is supported by means of pedestal bearing for the dimensions given below.
Outside diameter = 75 cm.
Length = 27.8 cm
Number of slots = 86
Size of slot = 1.11 cm × 5.24 cm
Depth of iron behind the slot = 9.26 cm
Ventilating ducts = 3, each 1 cm width Air gap length below main pole = 0.5 cm.
Main Pole (laminated) :
Total height = 24 cm with shoe
Width = 17.75 cm
Length = 25.7 cm
Interpole (solid):
Breadth = 4.63 cm Length = 20 cm
Air gap length below interpole = 0.8 cm
Thickness of yoke = 7.5 cm
Length of yoke = 40 cm
Commutator :
Number of commutator segments = 344
Diameter = 56 cm
Segment pitch = 0.51
Length = 12.35 cm
Number of brushes per spindle = 3
Shaft diameter below armature = 9 cm
shaft length between bearing centers = 120 cm.
50 M

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