These following pdf documents should be of help to you. I like the first document as the layout diagrams are very clear, however the second document gives all the specs very clearly, starting page 40.
Document 1: http://www.powergridindia.com/pgnew…
Document 2: http://www.squared.com/us/products/…$FILE/6020CT9401R3_02.pdf
Also, the Haryana Electricity Regulatory commission http://herc.nic.in/documents/html/s… insists that the following parameters be followed: Standardization of Sub-Station Layouts The Licensee shall develop standard layouts as detailed below.
18.104.22.168 33/11 kV Sub-Station
(a) The layout shall generally conform to relevant Construction Standards of Rural Electrification Corporation Ltd, CBI&P manual on layout of sub-station as applicable and provisions in Indian Electricity Rules, 1956 subject to the requirements mentioned in sub paragraph (b) below.
(b) The location of 33/11 kV S/S particularly in densely populated urban areas is dictated by the availability of adequate land and the approach route to the same. Such consideration/alternatives should be studied and provisions of higher capacity transformer and conductors /support should not be out rightly rejected as ultimately the load centres dictate the provision of required electrical facilities.
(c) The layout adopted shall include the following:
i. Independent Circuit Breaker control of 33 KV feeders and Transformers.
ii. Independent control of 11 KV Feeders.
iii. Single Bus sectionalised
(d) Spare bays should be provided for taking care of extension/augmentation of S/S capacity in future.
22.214.171.124 11/0.4kV 3-phase distribution transformers
(a) Transformers up to 200 KVA capacity other than those meant for indoor installation shall normally be pole mounted.
(b) The layout of the distribution transformers shall generally conform to relevant Construction Standards of Rural Electricity Corporation Ltd. and provisions in Indian Electricity Rules, 1956. The licensee may adopt more improved layout for urban areas as per project report.
(c) The distribution transformers shall be located as close to the load centres as possible. Transformers above 200 KVA capacity other than those meant for indoor installations shall be outdoor plinth mounted. Outdoor plinth mounted transformer should have adequate fencing arrangement and necessary provisions so that their installation in public places do not pose any danger accidentally or otherwise.
(d) Moulded Case Circuit Breakers of suitable ratings on the secondary side and fuse unit of suitable rating on primary side of transformers of capacity above 100 KVA shall be provided for protecting the transformers from over load and short circuits. Fuse units of suitable ratings shall be provided on the primary and secondary side of transformers of capacity up to and including 100 KVA for protecting the transformers from overload and short circuits.
(Rated by 6 Council Members)