Answer / satya narayan dutta

no power specification is limited for double earthing.Doube
earthing is required all medium and high voltage
installation.

Answer / prabhakaran

Double earthing is provided for critical equipments like transformer and generator were the earthing is essential. when one earth connection is correded or ineffective the other one will provide the connection to earth. if only one earth connection is provided if connection is not good the system become undgrounded.

Answer / dhamim

double earth is used to given minimum resistance to the flow of whole current of that apparatus in case short circuit or leakage or any other such fault happens  

Answer / venu sumie

If One Earth Connection is failed, another one will work.EX- at the single phase transformer earth failed,transformer produce high voltage nearly 650 volts instead of 240 volts. it is so dangerous ,even though we plug the battery charger at home we get massive shock.hence the transformers should be double earthed.

Answer / vatsal

As per Indian Standard (IS)3043-1987, it is recommended to use double earthing for medium voltages. Medium voltages are as high as 650V (but should not be lower than 250V). So in case of single phase, it will be usual to have single earthing and for 3 phase it is recommended to have double earthing.

Answer / atvk charyulu

refer IS:3043-1987

Answer / ravindra dikshit

Usually, wherever 3 phase supply is used, should have double earthing.

Answer / k.prakashchandra

I think that IE rules insist on 'two distinct earth connections'

Answer / sagarika

can any1 tell me y is double earthing reqd?

Answer / k.prakashchandra

And it is ensure the earth connection if one of the two is
severed.

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