2. DESIGN OF WINDOW

 We know, Q=3.33*f* _m*A_w*k_w* *10^-3

For 125KVA transformer ,k_w=10/(30+KV)

                                                    =10/(30+11)  =0.2439s

 Assuming the value of current density

 current density , = 2.3 N/mm²[for distribution transformer]

A_w= Q/(3.33*f* _m*k_w* *10^-3)

      =125/(3.33*50*0.0226*2.3*10³)

       =0.0577m²

Assume , window height to width ratio =3

           i.e  H_w/W_w=3

    where H_w=height of window

                W_w=width of window

Assuming window height to width ratio=3  Then, H_W=3*W_w

        Now A_w= H_w*W_w

               A_w=3* W_w²

W_w= A_w/3)

W_w= (0.0577/3)

W_w=0.139

And H_w=3* W_w

               =3*0.139

               =0.417

Distance between adjacent limb(D)= W_w+d =0.139+0.174 =0.312m