DESIGN SHEET

KVA 50 Phase 3 Frequency 50Hz Delta/Star

------ H.V 11KV -------- H.V 11KV
Line Voltage Phase Voltage ------ L.V 0.4KV --------- L.V 0.23KV

------ H.V 2.61 A -------- H.V 1.51 A
Line Current Phase Current ------ L.V 72.16 A --------- L.V 72.16 A
Type - Shell Type of Cooling --- ON
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CORE
1. Material 0.35 mm thick 92 Grade
2. Output Constant k 1.3
3. Voltage per turn Et 9.19V
4. Circumscribing circle diameter d 162.92 mm
5. Dimensions a 123.84 mm b 309.58 mm
6. Net iron area Ai 34.506×103 mm2
7. Flux density Bm 1.2 Wb / m2
8. Flux ɸm 0.041407 Wb
9. Weight 144.8 Kg
10. Specific iron loss 0.8 W/ Kg
11. Iron loss 115.84 W

YOKE
1. Depth of yoke DY 123.84 mm
2. Height of yoke Hy 309.58 mm
3. Net Yoke area 41.4×103 mm2
4. Flux Density 1 wb/ m2
5. Flux 0.041407 Wb
6. Weight 240.9 Kg
7. Specific iron loss 0.75 W/ Kg
8. Iron loss 180.67 W

WINDOW
1. Number 2
2. Window space factor Kw 0.2439
3. Height of window Hw 165.65 mm
4. Width of window Ww 82.85 mm
5. Window area Aw 13.72×103 mm2

FRAME
1. Distance between adjacent limbs D 245.77 mm
2. Height of frame H 744.63 mm
3. Width of frame W 413.38 mm
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4. Depth of frame Dy 123.84 mm ------------------------------------------------- Windings L.V H.V
1. Type of winding connections Sandwiched Sandwiched
2. Connections Star Delta
3. Conductor
Dimensions – bare 13×2.6mm2 Diameter – 0.71 mm Insulated 13×3.1 mm2 Diameter – 0.755 mm Area 33.8 mm2 0.75 mm2
4. Current density 2.13 A/m2 2.3 A/m2
5. Turns per phase 25 1191 (1220 at 2.5% tapping)
6. Turns Per coil 25 7 of 160 turns & 1 of 100 turns Per layer 12 7
7. Number of layers 2 24
8. Height of winding 156 mm 160.8 mm
9. Depth of winding 6.7 mm 8.14 mm
10. Insulation Between layers 0.5 mm press board 0.3 mm paper Between coils 5 mm spacers
11. Coil diameters Inside 165.92 mm 194.22 mm Outside 179.32 mm 202.36 mm
12. Length of mean turn 0.542 m 0.622 m
13. Resistance at 75oC 0.00842 Ω 39.29 Ω

INSULATION

1. Between l.v. winding and core = Press board wraps of 1.5 mm
2. Between l.v. winding and h.v. winding = Bakelized paper of 5 mm
3. Width of duct between l.v. and h.v = 5 mm
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TANK

1. Dimensions Height Ht 1.2 m Length Lt 0.32 m Width Wt 0.8m
2. Oil level 0.944 m
3. Tubes NIL
4. Temperature rise 22.75oC

IMPEDANCE

1. P.U. Resistance 0.00804
2. P.U. Reactance 0.005599
3. P.U. Impedance 0.00979

LOSSES

1. Total core losses 296.518 W
2. Total copper loss 468.05 W
3. Total losses at full load 764.57 W
4. Efficiency at full load and UPF 98.49%
5. Maximum Efficiency at 79.6% of full load
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