Question { Sify, 44260 }

Why we should use delta connection in primary and star
connection in an distribution transformer, which converts
400v a.c. voltage to 33kv.

Answer

We use in star connection in seconday connection becouse
need neutal point in load sied( some load supply need 3
phase and some need single phase)but it is remember that
only star connection use in distrubution side transformer.

Question { 9450 }

suppose we using 3 phase motor of 440 v means what range
of C.T. is require for measuring current ?

Answer

Mr. Naresh: Motor rating is always kW and transformer rating is KVA.

Alternator no depends on power factor.

For CT design, Should be need KW & voltage lavel.

Question { 11664 }

Why the resistance grounding (NGR) is better than Solid
grounding?

Answer

NGR: Neutral Grounding Resistance

NGR or grounding transformer using in MV voltage and Soild grounding is using in High & low voltage level as per standards.