Please Help me to answer obout it

The vector group of transformers were discussed n this forum many times earlier.

Dy5 is, D - High voltage Delta connected and y- low voltage Star connected with 5 indicating code for 150 ° phase shift. The vector group is important for transformer parallel operation.

For more information read the link

http://en.wikipedia.org/wiki/Vector_group

http://wiki.answers.com/Q/What_is_vector_group_of_transformer_and_how_we_can_define_the_vector_of_a_trfo_if_there_are_no_nameplate_exiest

Dear Guest,

By Dyn5 we mean as follows,

D = Primary winding is DELTA connected

y = Secondary winding is STAR connected

n = Star point in secondary is the neutral which is brought out to achieve phase voltage

5 = Indicates the CLOCK HOUR POSITION. Its 5 o clock which means the primary & secondary vectors are apart by 150 degrees mutually.

11= it indicates in the similar way as that of 5

The vector groups are mainly meant for paralleling. Transformers with similar vector groups only can be paralleled, otherwise there will be circulating currents in the total circuits.

In general the transformers with vector group Dyn11 are used for distribution purpose. Dyn5 are meant for specific purpose.