# Homework Help: Line Current for 30kW 3 phase motor

1. Mar 3, 2012

### p75213

1. The problem statement, all variables and given/known data
Calculate the line current required for a 30kW 3 phase motor having a power factor of 0.85 lagging if it is connected to a balanced source with a line voltage of 440V.

2. Relevant equations
P=√3Vl*IlCos ∅
Il=$\frac{P}{√3VlCos ∅}$

P=Average Power
Il=Line Current
Vl=Line Voltage
∅=∅v-∅i=∅Z

3. The attempt at a solution
Il=$\frac{30000}{440√3\times0.85}$=46.31A

2. Mar 3, 2012

### Staff: Mentor

http://img7.imageshack.us/img7/8738/p0813.gif [Broken]

Last edited by a moderator: May 5, 2017
3. Mar 4, 2012

### p75213

That's what I thought. This book has plenty of errors. Although it hasn't stopped me from learning a lot.

Last edited by a moderator: May 5, 2017