phase association of 3PH L&T static CT meter is wrong.
means 1PH & 1 CT connected properly and other 2 voltage and
CT's inter changed. what would be the impact in the reading?

Answer Posted / shankar

Lets us understand this problem by taking load as constant and the incoming supply initially it was RYB in sequence.
let Vr=10<0 Ir=5<-10
Vb=10<-120 Ib=10<-20
Vc=10<-240 Ic=15<-10
Now the total power is P=VrIrcos(-10)+VyIycos(-140)+VbIbcos(-250).
=41.5 watts.
Now lets us consider Y and B phases were wrongly connected to each other
Vr=10<0 Ir=5<-10
Vy=10<-240 Iy=10<-20
Vb=10<-120 Ib=15<-10
Now the total power is P=VrIrcos(-10)+VyIycos(-240)+VbIbcos(-130).
=3.781 watts
so the energy meter will records less units

Is This Answer Correct ?    2 Yes 2 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Define coil span?

629


If a surge divertor is required to be protected by 32 amp C Curve Circuit breaker does this limit the amount of protection from surges that you will acheive

1378


how to calculate micom relay earth falt time and current sertting

1822


How to convert 2 phase to 3 phase electricpower in induction moter?

1670


how unidirectional torque is produced in DC motor?

6291






HOW can i REuse the fused MLL LAMPS & GLS LAMPS at our factory

1420


What is the criteria that generally follow by distribution licenses to fix contact demand of their industrial customers?

1100


How can calculate the earthing strip of Copper/GI for rating of 30kV,discharge current 10KA Lightning arrester.

1862


Difference between earthing & grounding.?

1579


how does commutator convert a.c to d.c?

1762


how is working bearing heater?

1557


difrent between vcb acb sf6 and mccb breakers

4592


What are the types of feedback oscillators?

811


what is model question rrb junior engineer electrical gr.II

1541


Can anybody post questions asked in Engineers India Limited Interview? Thanks in advance.

1898