# Two watt meter method and power factor



## Chaser (Apr 2, 2017)

Given two wattmeters ( w1 and w2) reading from a 3 phase circuit, how do you identify if a load is capacitive or inductive? please advise.


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## Troll (Apr 2, 2017)

you'd have to be given more information than just that


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## HotFudge (Apr 3, 2017)

I believe that its capacitive (sending VA), then you have P &lt; 0 and it's inductive (receiving VA), P &gt; 0. Hopefully this helps


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## Troll (Apr 3, 2017)

HotFudge said:


> I believe that its capacitive (sending VA), then you have P &lt; 0 and it's inductive (receiving VA), P &gt; 0. Hopefully this helps


real power (P) cannot be negative. only reactive power (Q) can


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## TWJ PE (Apr 3, 2017)




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## TWJ PE (Apr 3, 2017)




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## HotFudge (Apr 3, 2017)

Troll said:


> real power (P) cannot be negative. only reactive power (Q) can


You are right i should have typed capacitive as (KVAR) Q&lt;0


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## rg1 (Apr 6, 2017)

Chaser said:


> Given two wattmeters ( w1 and w2) reading from a 3 phase circuit, how do you identify if a load is capacitive or inductive? please advise.


In two watt meter method

(Sings of W1, W2 preserved)

W1+W2= Sqrt3 V(line) I(line) cos(phi) =Real power consumed by Load=P

and W1-W2= V(line) I(line) Sin(phi)= 1/sqrt3 of Reactive power.=Q/sqrt3

The sign of Q will decide whether the pf is lag or lead.


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