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Hi DIYnot,
I have a bungalow that is out in the sticks which is connected using TNC-S. The cable feed is a combination of overhead and underground and must be about 300-400m from the tranformer in a garden nearby.
I considered the case of a loss of the incoming combined TN which could result in the entire earthing system of the bungalow becoming live. I know it is quite rare but have read of cases where this has happened which quite nasty results.
I have been mulling over this problem for quite some time now.
I am soon having the consumer unit changed to a Hager Design 50 where all circuits will be RCBO protected. At the same time I wondered if it would be possible to add one or more earth rods which I could connect to the incomming TN connection to provide an earth connection if the incomming TN connection was lost.
Would there be a problem in doing this?
As an alternative I did consider converting the TNC-S system to TT in which case the incomming TN would only be used as the neutral and I would then provide my own earth again using a number of earth rods only this time there would be no connection to the incomming TN.
Would there be a problem in doing this?
Is either method better than the other?
Any help/comments would be greatfully appreciated.
Regards
FarmerJo
I have a bungalow that is out in the sticks which is connected using TNC-S. The cable feed is a combination of overhead and underground and must be about 300-400m from the tranformer in a garden nearby.
I considered the case of a loss of the incoming combined TN which could result in the entire earthing system of the bungalow becoming live. I know it is quite rare but have read of cases where this has happened which quite nasty results.
I have been mulling over this problem for quite some time now.
I am soon having the consumer unit changed to a Hager Design 50 where all circuits will be RCBO protected. At the same time I wondered if it would be possible to add one or more earth rods which I could connect to the incomming TN connection to provide an earth connection if the incomming TN connection was lost.
Would there be a problem in doing this?
As an alternative I did consider converting the TNC-S system to TT in which case the incomming TN would only be used as the neutral and I would then provide my own earth again using a number of earth rods only this time there would be no connection to the incomming TN.
Would there be a problem in doing this?
Is either method better than the other?
Any help/comments would be greatfully appreciated.
Regards
FarmerJo