20mva gtp r3

ED/120637/GTP/R3

No. Description Unit of Measurement

Details

1 Manufacturer/country of Origin TELK, KERALA, INDIA

2 Continuous maximum rating a) ONAN MVA 15 b) ONAF MVA 20

3 Voltage ratio at no-load and principal kV 11.5/33 (LV/HV)

4 Tapping range +5% to -15%

5 Size of tapping step 1.6670%

6 No. of steps 12 (13 taps)

7 Vector group YNd11

8 On-load Tap Changer

a) Manufacturer TELK

b) Type reference YE on HV Nuetral

c) HV or LV winding HV

d) Range on/off load On load

e) Type test certificate ref./date -

9 Type of cooling ONAN/ONAF

10 Winding temperature rise at CMR under site service conditions

°C 50

11 Top oil temperature rise at CMR under site service conditionsa) ONAF rating °C 40

b) ONAN rating (full rating required) °C 40

12 Hot spot temperature rise °C as per IEC 60076

13 Flux density (no-load) Tesla 1.6 (max.)

14 No-load loss kW 9.5 kW (max.)

15 Load loss at 75°C at CMR

a) ONAF rating kW 97 kW (max.)

b) ONAN rating (full rating required) kW 54.5 kW (approx..)

16 Total loss at 75°C and normal ratio at CMRa) ONAF rating (including aux. losses) kW 109 kW (max.)

b) ONAN rating (full rating required) kW 64kW (approx.)

TECHNICAL PARTICULARS AND GUARANTEES 20MVA 11.5/33 kV (LV/HV) TRANSFORMERS

ED/120637/GTP/R3


Details


17 Regulation at 75°C and normal ratio at CMRa) ONAF rating % 1.27 (approx.) at upf

b) ONAN rating (full rating required) % 0.87 (approx.) at upf

18 Impedance voltage at CMR

a) ONAF rating % 12.5 (subject to IEC tolerance)

b) ONAN rating (full rating required) % 9.3 (approx.)

19 Zero sequence impedance at CMR

a) ONAF rating % 10 (approx.)

b) ONAN rating (full rating required) % 7.5 (approx.)

20 Noise level at CMR

a) ONAF rating dBA 71 (approx.)

b) ONAN rating (full rating required) dBA 65 (approx.)

21 Type of construction (shell or core) Core type

22 Winding (brazed or crimped) Winding brazed, leads crimped23 Thickness of tank

a) sides 10 (approx.)

b) Bottom 20 (approx.)

24 No. of cooler banks 2 x 50%

25 No. of air blowers per coller bank Adequate

26 Total oil including cooling system litres 9000 (approx.)

27 Total weight of complete transformer tonne 37 (approx.)

28 Weight of transformer for transport tonne 28. 5 (approx.) [Oil filled condition]

29 Manufacturer, type and class of oil IEC 296-1982,Class1. Apar/Savitha/Raj Lubricants

30 Transformer bushings

a) Manufacturer TELK

b) Type reference Plain Porcelain type

HV LVc) Rated current A 630 2000

d) Lightning impulse voltage withstand kV 170 95

e) Power frequency voltage withstand kV 70 38f) Total creepage distance of insulator mm 25mm/kV 25mm/kV

g) Type test certificate ref./date - -

ED/120637/GTP/R3


Details


31 Brief description of transformers or parts thereof subjected to short circuit test or for which short circuit calculations are available

NPC35 MVA, 21/6.9 kV

32 Highest System Voltage for

a) 33kV 36kV

b) 11kV ` 12kV

33 HVN BCT DetailsCore - 1Current Ratio 400-200/1 AClass PSVk 63 / 90 VoltsRct 2 / 1 ohmI0 20 / 50mA at Vk/2

Core -2 Current Ratio 400-200/1 AClass 5PALF 20Burden 15VA

34 overloading capability for 4 hours with 60% initial loading at specified

As per IEC 60076-7. 110% Continuous.

35 Insulation Level (Basic impulse withstand voltage/AC withstand HV winding kV

Peak/kVrms170/70

LV winding kV Peak/kVrms

75/28

36 Efficiency at full load % 99.4737 Inrush current (HV) kA 2.538 Phase current

HV current A 349.9LV current A 579.7

39 Reactance (HV) ohms 2.6 Approx.Resistance (HV) ohms 0.11 Approx.Zero sequence reactance % 9.98

40 Cooling Systema) No of radiator on the transformer tank 6b) Thickness of radiator plates mm 1.2

ED/120637/GTP/R3


Details


c) Fan motor(Type/make/no of fans/motor rating)

Propeller type Marathon-6nos 0.37kW

** Note:- Item no.30:- Since the bushings are placed inside airfilled cable box, 25mm/kv creepage distance is sufficient which is also as per Cl.No: 2.6 section IID of OES 6. In this clause creepage distance of HV bushing shall be 805mm and that of LV bushing shall be 295mm,the bushings offered by us is having creepage distance of 900mm and 440mm for HV and LV respectively. Item no.37:- The no load current of transformer in steady state condition is very small compared to full load current however no load current can exceed the rated current at the time just after switching in and may last for onlyfew cycles. Hence it is very difficult to measure and plot its value verses time manually.so plz consider the same.

20mva gtp r3

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