depends upon the configuration of the
transformer...whether it is star delta,star star.....

If blowing of HT side fuses result in zero magnetising
current in the primary winding, then there will not be any
voltage in ry,rb,yb on the secondary side

Ro -resistance at o degre centigrade 
Rt -resistance at t degre centigrade 
we have formula 
Rt = Ro(1+alpha t)
here alpha is cofficient of resistivity

if i0.0
then o0.0
othw reset

1. Create a Push button
2. connect a Counter series to PB
3. create a compare button 
4. initilize 1 at one end
5. Counter output in another
6. Connect the Coil which has to be energised
7. initilize 2 at one end
8. Counter output in another
9. Connect the Coil which has to be deenergised 

SIMPLE LOGIC FOR MOTOR ON AND OFF 

   P.B(NO)                    Motor
[----[ ]----------i--------------()---
[    I0.0         i             Q0.0
[                 i
[   P.B(NC)       i
[----[\]-----( )--i
[    I0.1    Q0.0*
[

NO - Normally Open
NC - Normally Close

I0.0 - Input Address in PLC for P.B(NO) to Start the motor.
I0.1 - Stop Push Button(NC)Address.
Q0.0 - Out put adress(Motor)
* - Means the output Q0.0 is used for hold the motor ON.

Further Details - isonafar@gmail.com

[----[ ]----------i--------------()---]
[    PB           i              OP   ]
[                 i                   ]
[                 i                   ]
[----[ ]----------i                   ]
[    OP*                              ]

OP* Output Energies memory contact!

Acually the question is for using only one PB for ON and 
OFF the motor, not one PB for ON and one PB for OFF.

[     PB         M2         O/P    ]
[-----[ ]--------[/]--------( )----]
[           i                      ]  
[     O/P   i                      ]
[-----[/]---i                      ]
[                                  ]
[     PB     O/P              M1   ]
[-----[/]----[ ]-------------( )---]
[                                  ]
[     PB     M1      O/P      M2   ]
[-----[ ]----[ ]-----[ ]-----( )---]
[                                  ]

transformer copper loss is directly propotional to 
current&iron loss is directly propotional to voltage. so 
transformer rating is in kva.

we can't find the correct powerfactor , this is depn upon 
the loads thats why we are calling KVA..

In trafo we dont know what types of load connected at a 
time.i.e. inductive or rasistive but in motor load is same.

SHORT CIRCUIT CURRENT IS DEPEND UPON TYPE OF FAULT OCCURE.
BY DESIGN EQUIVELENT CKT OF PERTICULAR FAULT. 
WE CAN GET SC CURRENT

Simply calculate total KWH and KVH of last 24 Hrs and 
Divide into-Total KWH/Total KVH=Avg PF of last 24Hrs

thanks, but  cosider that R ph pf is 0.8,y-ph pf is 0.6,and 
b ph pf is 0.7 what vlb the overall pf of three phase 
unbalanced 3phase system .

When and where is your interview?

I Am Not getting u r Question Actually The Surge Arrestor 
For Medium & High Voltage Substation is as
Voltage Rating Of LA ( KV )= 0.8* LINE Volgage of the 
Substation.

here 0.8 is earthing coefficent factor for solidely 
grounded system.....

150/20 is the rating of voltages indicated on the surge 
arrester.
It means that the surge arresters step down the high 
voltage of 150  to 20.

Differential relay is a current sensing zone protection 
relay.It is used to protect alternators,transformers from 
internal short ckt,internal earth faults.