Please could someone explain what the cos means

Thread Starter

ElecNerd

Joined Jan 2, 2011
20
Hi,

Whilst I understand the following in terms of identifying the phase and line voltages etc please could someone advise me what I would put into the calculator for cosθ as detailed below. I seem to understand it and then they throw this in for good measure :).

In case of delta conneted load in above fig(a) the total active power is equal to three times the power of one phase.


Since the line current in the balanced delta connected loads is

substituting this eq the total active power becomes


Thank you very much for your help!
 

edgetrigger

Joined Dec 19, 2010
133
cosθ is the phase agle between the current and the voltage. If you are calculating for a resistor just enter 0 in the calculator, or cos0 = 1 , you could ignore it for a resistor
 

edgetrigger

Joined Dec 19, 2010
133
furhter for a pure inductor or a capcitor θ = 90. Mind you, you have to set the calculator to degree mode before doing calculations. If it is in radian then calculation will go for a toss.
 
Last edited:

hgmjr

Joined Jan 28, 2005
9,027
The cosine of the phase between the voltage and the current is also referred by the term "power factor".

hgmjr
 
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