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 |