Sub Station Abstracts -(Part-2)

SUB STATION ABSTRACT -(PART-2)

SUB STATION CAPACITY & SHORT CIRCUIT CURRENT CAPACITY:

As per GERC

Voltage Sub Station Capacity Short Circuit Current 400 KV Up to 1000 MVA 40 KA (1 to 3 Sec) 220 KV Up to 320 MVA 40 KA (1 to 3 Sec) 132 KV Up to 150 MVA 32 KA (1 to 3 Sec) 66 KV Up to 80 MVA 25 KA (1 to 3 Sec) 33 KV 1.5 MVA to 5 MVA 35 KA (Urban) (1 to 3 Sec) 11 KV 150 KVA to 1.5 MVA 25 KA (Rural) (1 to 3 Sec) 415 V 6 KVA to 150 KVA 10 KA (1 to 3 Sec) 220 V Up to 6 KVA 6 KA (1 to 3 Sec)

 SUB STATION CAPACITY & SHORT CIRCUIT CURRENT CAPACITY:

As per Central Electricity Authority

Voltage Sub Station Capacity Short Circuit Current 765 KV

4500 MVA

31.5 KA for 1 Sec 400 KV

1500 MVA

31.5 KA for 1 Sec 220 KV

500 MVA

40 KA for 1 Sec 110/132 KV

150 MVA

40 KA or 50 KA for 1 Sec 66 KV

75 MVA

40 KA or 50 KA for 1 Sec

 MINIMUM GROUND CLEARANCE AND FAULT CLEARING TIME:

Voltage Min. Ground Clearance Fault Clear Time 400 KV 8.8 Meter 100 mille second 220 KV 8.0 Meter 120 mille second 132 KV 6.1 Meter 160 mille second 66 KV 5.1 Meter 300 mille second 33 KV 3.7 Meter 11 KV 2.7 Meter

 BUS BAR AMPERE RATING:

For Phase Bus bar Aluminium 130 Amp / Sq.cm or 800Amp / Sq.inch. For Phase Bus bar Copper 160 Amp / Sq.cm or 1000Amp / Sq.inch For Neutral Bus bar Same as Phase Bus bar up to 200 Amp than Size of Neutral Bus bar is at least half of Phase Bus bar.

 BUS BAR SPACING:

Between Phase and Earth 26mm (Min) Between Phase and Phase 32mm (Min) Bus bar Support between Two Insulator 250mm.

 SOUND LEVEL OF DIESEL GENERATOR (ANSI 89.2&NEMA 51.20):

KVA

Max. Sound Level

<9 KVA 40 DB 10 KVA to 50 KVA 45 DB 51 KVA to 150 KVA 50 DB 151 KVA to 300 KVA 55 DB 301 KVA to 500 KVA 60 DB

IR VALUE OF TRANSFORMER:

IR Value of Transformer

Voltage

30°C

40°C

50°C

66KV

600MΩ

300MΩ

150MΩ

22KV to 33KV

500MΩ

250MΩ

125MΩ

6.6KV to 11KV

400MΩ

200MΩ

100MΩ

<6.6KV

200MΩ

100MΩ

50MΩ

415V

100MΩ

50MΩ

20MΩ