Transformer Star delta

Step-Up transformers usually connected as star-delta with the star point at the primary connected to earth for provision of earth fault protection and to circulate any earthing current to ground in case of any imbalances, while distribution transformers are connected as delta-star with the star point at the secondary connected to the neutral to supply domestic loads which normaly rates at 240v,230v/110v, etc...phase+ neutral.

any comments welcomed,

Transformer connection is normally defined by means of a System Study.

This includes:

-fault current elimination time

-fault current path

-overvoltages

-harmonics restraint

-zero sequence component circulation

In regular installations, it is common to use the delta(high)wye(low) connection. Then it must be decided if the star center will be grounded or not.

Center of wye grounding has some advantages and ungrounding has others.

You can refer to IEEE Std C62.92.1-2000 to more detailed information.

Regards

elbf2801

elbf2801 , Your explanation is nice and IEEE reference is very nice.

I suspect we are doing this guy's homework for him

It's not always the case that the secondary is 'star` or 'wye`.

Just the most common configuration because it saves copper & cost for most installations.

I've seen center tapped delta, open delta, and delta secondarys on occaision.