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Question
what is the difference between KW and KVA?
 Question Submitted By :: Electrical-Engineering
I also faced this Question!!     Answer Posted By  
 
Answer
# 1
kw means that it is the power deliverd to the load. where
as the kva is the power can be meet the load demand. so
that kva is not with respect to load.

if we simply says kw=kva*power factor.

so that only alternators and transformers(giving supply,not
respect to load) specified in kva and load(motors)
specified in kw.
 
Is This Answer Correct ?    244 Yes 36 No
Navaneethan
 
Answer
# 2
KW= Active power
KVA= Apparent power
 
Is This Answer Correct ?    151 Yes 21 No
Imran
 
 
 
Answer
# 3
kW is the unit of real power & kVA is the unit of Apparent
power.

Apparent Power= real power + reactive power

Looking at different electrical equipment you will notice
that the power ratings are either expressed in kVA
(kilo Volt Ampres) or sometimes in kW (kilo Watts). The
next question is what’s the difference? Both are
measurements of power however they are truly different.
To understand the differences consider how each are
derived. kW is called actual or real power, or simply
the amount of power that is available to do real work. kVA.
On the other hand kVA is known as “apparent”
power. This is because only a portion of the available kVA
may be available to do real work. The remainder
is simply excess current.
The difference between kVA and kW really depends on the
power factor (PF). When the voltage and
current are in phase with each other in an AC circuit, the
power factor is 1.0 or “unity”. The more the
voltage falls out of phase with the current the lower the
power factor becomes and the less “real power” or
kW the device uses; however it may still be using the same
amount of current as a device with a higher
power factor. Power factor will be "leading" or "lagging"
depending on which way the load shifts the
current’s phase with respect to the voltage’s phase.
Inductive loads cause current to lag behind voltage,
while capacitive loads cause current to lead voltage hence
leading or lagging power factor.

kVA = Volts x A
kW= Volts x Amps x Power Factor or [kVA x Power Factor]

The next question is why express the kVA value of a device
and what use is
kVA if only part of it can do work? The reason kVA is used
as a rating is
because the rating of an electrical device is dependent on
the amount of
current they can sustain. A kW rating does not indicate how
much current
a device can carry (as the power factor may not be known)
where kVA
does indicate the maximum current at a specific voltage
level.
 
Is This Answer Correct ?    124 Yes 13 No
Raghav
 
Answer
# 4
kw is a real(Active) power that depends on the load that we use.
KVA is a apparent power which is the maximum power that can
be produced by source.

KVA = voltage x current

KW= voltage x current x power factor

power factor depends upon load.

Apparent Power(KVA)= real power(KW) + reactive power(KVAr)
 
Is This Answer Correct ?    63 Yes 16 No
Azarudeen
 
Answer
# 5
in the ideal conditions the power of the load is equal to
its KVA , but practically a phase difference will happen
between the volt and the current and it will lead to reduce
the KVA to the KW , the ratio between the KW power (Actual
power ) & the KVA (Appearent power) is the power factor .
In my opinion we can say the KVA is the theoritical value
of the power , and it can be equal to the Kw if no phase
difference happened.
 
Is This Answer Correct ?    28 Yes 8 No
Ammar
 
Answer
# 6
In the ideal conditions the power of the load is equal to
its KVA , but practically a phase difference will happen
between the volt and the current and it will lead to reduce
the KVA to the KW , the ratio between the KW power (Actual
power ) & the KVA (Appearent power) is the power factor .
In my opinion we can say the KVA is the theoritical value
of the power , and it can be equal to the Kw if no phase
difference happened.

The simple way is kw=kva*power factor.
 
Is This Answer Correct ?    18 Yes 6 No
Kirankumar
 
Answer
# 7
kw-load output
kva-power output
 
Is This Answer Correct ?    3 Yes 1 No
Ramesh
 
Answer
# 8
Looking at different electrical equipment you will notice that the power ratings are either expressed in kVA (kilo Volt Ampres) or sometimes in kW (kilo Watts). The next question is what’s the difference? Both are measurements of power however they are truly different. To understand the differences consider how each are derived. kW is called actual or real power, or simply the amount of power that is available to do real work. kVA. On the other hand kVA is known as “apparent” power. This is because only a portion of the available kVA may be available to do real work. The remainder is simply excess current.
The difference between kVA and kW really depends on the power factor (PF). When the voltage and current are in phase with each other in an AC circuit, the power factor is 1.0 or “unity”. The more the voltage falls out of phase with the current the lower the power factor becomes and the less “real power” or kW the device uses; however it may still be using the same amount of current as a device with a higher
power factor. Power factor will be "leading" or "lagging" depending on which way the load shifts the current’s phase with respect to the voltage’s phase. Inductive loads cause current to lag behind voltage, while capacitive loads cause current to lead voltage hence leading or lagging power factor.
The next question is why express the kVA value of a device and what use is
kVA if only part of it can do work? The reason kVA is used as a rating is
because the rating of an electrical device is dependent on the amount of
current they can sustain. A kW rating does not indicate how much current
a device can carry (as the power factor may not be known) where kVA
does indicate the maximum current at a specific voltage level.
 
Is This Answer Correct ?    2 Yes 0 No
Rajesh Mohanan
 
Answer
# 9
In basic electrical, when heat is produced, we say work is
done. kW is a real or active power because it causes radiation,
dissipation, and/or mechanical motion and kVA produces both heat
and inductive / capacitive fields.
Example: In a motor, kW is consumed in the resistance of the
motor winding and is causing heating of the motor winding
only. And, if kVA be not there then motor will not rotate
because kVA is the power consumed in the motor winding
resistance as well as producing the magnetic field in the
rotor winding.
 
Is This Answer Correct ?    2 Yes 1 No
Sethar12
 
Answer
# 10
KW is the real(active) power that depends on load that we
use whereas KVA is the apparant power & it is the maximum
power that is used by the source.


KVA= VI
KW= VICOS@
Where cos@ depends on load.
 
Is This Answer Correct ?    1 Yes 0 No
Dinesh Chaudhary
 

 
 
 
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