Whats the difference b/w VA and watts ??

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hameeds01

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va watt cos

hello everyone,
i want to know the difference b/w VA and watts ,
It is written as 2000VA / 1200w on a UPS what does it means? What’s the relationship b/w VA and watts? How to calculate the wattage from VA? What r their formulas?
 

the difference in real power and total power

VA is total power, Watts is real power


real power in your circuit performs WORK (i.e. useful output). some of your supply's input power does this work (hopefully most of it) but some goes off to perform other functions, such as "establishing the field" and so forth.

total power = real power + reactive power
S = P + jQ

where the units are:

VA = Watt + VAR

Mr.Cool
 

VA is the power delivered if the load is purely resistive.... if the load has capacitance or inductance in it, this power gets divided into two parts, real (Watt) and reactive (VAR)..... where real part is the one that does the actual work, while reactive is used in energizing and establishing field, the relationship is not simple algebraic but complex
 

In AC circuit, there is what we called Apparent Power, with the unit of volt-ampere (VA). It is the complex sum of Real Power (Watts) and Reactive Power (VAr). Apparent power is basically the product of the source voltage and current, hence the name volt-ampere. Volt-ampere and watts are related by the formula:

W = VA * cos θ

cos θ is the power factor.

Depending on the circuit, there are a lot of ways to compute for Watts using the values of VA.
 

yes it is based on real &reactive powers
try to go through network books u can understand them better
 

VA volt ampere is the total power, watts is the power delivered to load that is real power.

I hope u remembered ,power factor is the ratio of real power to apparent power.
If you want real power then multiply power factor with VA.

for example if the machine/UPS is having 0.8 power factor and it is 10 KVA then in terms of watts is obtained as 0.8*10KVA=8000 W.That means output of the UPS can be connected upto 8000W/230V=35 amps load can be connected
 

Hi,
In simple words Va is the power with out power factor and
Watt is the power with power factor and is always lesser than VA Power
 

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