Re: Delta/ delta , Transformer.

Spir Georges GHALI

abrahan said:

There is a transformer which has primary is Delta and Secondary also Delta. this transformer is used for light & other single phase & 3 phase supply.

415 Delta/ 435 / 240 Delta

my question is

 How we can use this transformer single phase purpuse ( where is the Neutral in Delta system)

Dear Mr. Abraham ;


In some case, we use a transformer ” Dd… ” where we haven't a neutral in secondary, but in this case we should select the output voltage of secondary accordingly to the supply voltage of the loads that will be electrified by this transformer. Asume that all loads are ” single phase – 230V “, so, the secondary output voltage should be ” 230V ” between ” 2 phases ” and each load should be connected to ” 2 phases “.

For exp. we use the ” Dd… transformers ” in ” LV/LV ” when we change the earthing system from ” … ” to ” IT  without neutral “, because with this kind of transformer we decrease the number of earth fault that can happen, but we should be carful of the loads' supply voltage.