Ring Main Unit

Short answer is obviously no for both homework/general interest questions. A substation is not some black box that just takes one voltage and spits out another using ohms law.

When your Factory or township is fed from two different substations of Public Electricity Board ( Government or Corporation) or Private Electric Company they make a ring main system for the benefit of both the supplier and the customer. But if two interdependent feeders are extended to the customers premises from single source( same substation) it is for the customer to design their own suitable ring main system for their benefit depending on the load pattern, distribution system, location of the substations and the available financial resources. If you want total capacity single ring main then the cable network has to cater for full capacity of the connected load of the customer which is a costlier design. Instead you can have two different ring main systems . You can have half the substations on one side of the bus with first incomer and other half with the second incomer and have a bus coupler in the middle. So the design will depend on local conditions.

Are you installing one substation or two, not that it matters. You are given a maximum demand from the Electrical Board. Your job is to ensure you do not exceed that demand. It does no matter which side you monitor. IF you have 2 subs there is equipment that will allow you to integrate the demands of both to obtain the total maximum. I would think the 11 kv side would be cheaper.

If the rated voltage of equipments like motors in the factory is 400, locate package substations(11kV/400)around the factory.

See Mr. Muthuvel,

u have asked yes or no questions - "RMU can be connected for 110kV voltage level" - YES it can be connected.

"Likewise can we maintain that RMU scheme in 11kV voltage level" - YES it can be maintained in 11KV RMU.

i cant able to understand the meaning of "SCHEME" wheather u are asking the detailed / complete ring main grid / circuit with all specifications?

Dear Mr.Shajahan

If you can connect RMU in 110kV voltage level and 11kv in same substation.Kindly send me the that Single line diagram of the sub-station from 110kV voltage level to 11kv voltage level(note:that sub-station should be approved and executed without any problem)

RMU is available up to 22-34.5 kV.

I do not see how, even with 110KV available, you can do without a 11 KV (or 22KV or even 36KV - as in Spain) loop, on which you will connect MV/LV transformers with RMUs.