# Newbie trying to understand

Discussion in 'Homework Help' started by Graysonrobert, Aug 7, 2014.

1. ### Graysonrobert Thread Starter New Member

Aug 7, 2014
3
0
A problem that my professor gave me.

A 5kw 240v motor has current measured at 14Amps. The meter shows that the motor is drawing 2kw. Draw vectors of voltage and current! And calculate power factor... I'm lost any help would be appreciated

2. ### Kermit2 AAC Fanatic!

Feb 5, 2010
3,778
932
p.f. = watts / volt amperes

so 2000 / 240x14 = p.f.

3. ### Graysonrobert Thread Starter New Member

Aug 7, 2014
3
0
That would be 1.68. I didn't think the pf could be more than 1

4. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
782
No - that would be 0.595, which is OK.

5. ### shteii01 AAC Fanatic!

Feb 19, 2010
3,386
497
I thought 14 A applied to the 5 kW value. Why are you using it for 2 kW?

6. ### t_n_k AAC Fanatic!

Mar 6, 2009
5,448
782
The motor is stated to be drawing 2kW real power. The 5kW is probably indicating the motor (nameplate) rating.

7. ### shteii01 AAC Fanatic!

Feb 19, 2010
3,386
497
Ok. Thank you.