The SF6 gas insulated metal enclosed switchgear shall be totally safe against inadvertent touch of any of its live constituent parts.
The arrangement of gas sections or compartments shall be such as to facilitate future expansion of incomer bay with any make on either end without any drilling, cutting or welding on the existing equipment. To add equipment, it shall not be necessary to move or dislocate the existing switchgear bays.
The design should be such that all parts subjected to wear and tear are easily accessible for maintenance purposes. The equipment offered shall be protected against all types of voltage surges and any equipment necessary to satisfy this requirement shall be deemed to be included.
The required overall parameters of GIS are as follows:
|No.||Technical Particulars||220kV System|
|1.||Rated Voltage||245 kV (rms)|
|2.||Rated frequency||50 HZ|
|4.||Rated Power frequency withstand Voltage (1 min) line to earth||460 kV (rms)|
|5.||Impulse withstands BIL 1.2/50/mic. Sec) Line to earth||±1050 kVp|
|6.||Switching impulse voltage (250/2500 mic-sec)||–|
|7.||Rated short time withstand current (1 sec)||40 kA (rms)|
|8.||Rated peak withstand current||100 kA (peak)|
|9.||Guaranteed maximum gas losses or complete installation as well as for all individual sections in %.||As per IEC- 62271-203|
|10.||Seismic level||Zone-IV, as per
The metal-enclosed gas insulated switchgear, including the operating devices, accessories and auxiliary equipment forming integral part thereof, shall be designed, manufactured, assembled and tested in accordance with the IEC- 62271-203/IEC-62271-200 publications including their parts and supplements as amended or revised to date.
The metal-enclosed gas-insulated switchgear, including the operating devices, accessories and auxiliary equipment forming integral part thereof, shall be designed, manufactured, assembled and tested in accordance with the following International Electro-technical Commission (IEC) standards including their parts and supplements as amended or revised till date:
- IEC 62271-203 – Gas Insulated metal-enclosed switchgear for rated voltages above 52KV.
- IEC 60376 – New sulphur hexafluoride
- IEC 62271- 100 – High voltage alternating current Circuit breakers
- IEC 60694 – Common clauses for high voltage Switchgear and control-gear standards
- IEC 62271-102 – Alternating current disconnectors (isolators) and earthing switches.
- IEC 61128 – Alternating current disconnectors. Bus-transfer current switching by disconnectors.
- IEC 61129 – Alternating current earthing switches. Induced current switching
- IEC 66044-1 – Current transformers
- IEC 66044-2 – Voltage transformers
- IEC 60137 – Bushings for alternating voltages above 1000 V
- IEC 60859 – Cable connections for gas-insulated switchgear
- IEC 60480 – Guide to checking of sulphur hexafluoride taken from electrical equipment
- IEC 60099-1/4 – Non-linear resistor type arresters for AC systems
- IEC 60439 – Factory-built assemblies of low-voltage switchgear and control gear.
- IEC 60427 – Report on synthetic testing of high-voltage alternating current circuit breaker.
- IEEE 80 (2000) – IEEE Guide for Safety in AC Substation grounding.
- CIGRE-44 – Earthing of GIS application guide. (Electra no.151, Dec’93)
The manufacturer shall list all applicable standards; codes etc. and provide copies thereof for necessary approval.
In case the requirements laid down herein differ from those given in above standard in any aspect the switchgear shall comply with the requirements indicated herein in regard thereto.
|Title:||General Tender Technical Specification For SF6 Gas Insulated Metal Enclosed Switchgear (GIS)|
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