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Question
what is the difference between KW and KVA?
 Question Submitted By :: Bharath
I also faced this Question!!     Rank Answer Posted By  
 
  Re: what is the difference between KW and KVA?
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 ?    242 Yes 36 No
Navaneethan
 
  Re: what is the difference between KW and KVA?
Answer
# 2
KW= Active power
KVA= Apparent power
 
Is This Answer Correct ?    150 Yes 20 No
Imran
 
 
 
  Re: what is the difference between KW and KVA?
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
 
  Re: what is the difference between KW and KVA?
Answer
# 4
The power consumed by the resistive element of the circuit
with Impedance is termed as Active Power
P= V*I*p.f.
P=I*Z*I*(R/Z)
P=square(I)*R in Wattd
The power consumed by the Impedance of the circuit is
called as Active Power
S=V*I
S=I*Z*I
S=square(I)* Z expressed in VA
 
Is This Answer Correct ?    8 Yes 31 No
Shyam Majgaonkar
 
  Re: what is the difference between KW and KVA?
Answer
# 5
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 ?    62 Yes 15 No
Azarudeen
 
  Re: what is the difference between KW and KVA?
Answer
# 6
KW means machanical power(mechanical load) o/p of the system
but KVA means electrical power output(electrical load)
 
Is This Answer Correct ?    15 Yes 70 No
Maharajan
 
  Re: what is the difference between KW and KVA?
Answer
# 7
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
 
  Re: what is the difference between KW and KVA?
Answer
# 8
kw IS THE POWER DRAWN BY A LOAD LIKE ELECTRIC
MOTOR,HEATER,FAN ETC,

WHEREAS kva IS THE POWER WHICH WE CAN GET FROM A POWER
CONVERTOR SOURCE LIKE INVERTER,UPS,DG ETC.
ALSO kw=kva*POWERFACTOR(VIcosǿ)
 
Is This Answer Correct ?    9 Yes 29 No
Rajinder Kumar
 
  Re: what is the difference between KW and KVA?
Answer
# 9
kw IS THE POWER DRAWN BY A LOAD LIKE ELECTRIC
MOTOR,HEATER,FAN ETC,

WHEREAS kva IS THE POWER WHICH WE CAN GET FROM A POWER
CONVERTOR SOURCE LIKE INVERTER,UPS,DG ETC.
ALSO kw=kva*POWERFACTOR(VIcosǿ)



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.


KW means machanical power(mechanical load) o/p of the system
but KVA means electrical power output(electrical load)


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




The power consumed by the resistive element of the circuit
with Impedance is termed as Active Power
P= V*I*p.f.
P=I*Z*I*(R/Z)
P=square(I)*R in Wattd
The power consumed by the Impedance of the circuit is
called as Active Power
S=V*I
S=I*Z*I
S=square(I)* Z expressed in VA




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 ?    9 Yes 15 No
Bhushan
 
  Re: what is the difference between KW and KVA?
Answer
# 10
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
 

 
 
 
Other Electrical Engineering Interview Questions
 
  Question Asked @ Answers
 
How Can we calculate the rating of a cable?Show the formula? Jindal 2
what is the role of reactive powerin transmission and distribution?   2
what is the meaning of cable Glanding can you explain brifly?   2
WAT IS MEANT BY COLD AND HOT START OF A MOTOR?? HOW DOES IT AFFECT A MOTOR'S PERFORMANCE??   3
what is meant by armature reaction & where its happen ?   3
Dear Friends, I have a 500KVA transformer supplying whole factory having 3 phase and single phase mixed loads. Power room has ammeters connected via CTs for individual phase. Now I know that readings shown on meter for each phase say R,Y and B are line currents. But when I want to know the total on transformer do I need to add the currents of all three phases readings shown on meter or value for anyone phase will give me the correct power load on transformer for that point of time. 2. If ammeter shows unbalanced readings for R,Y, B phases say 150, 250 and 300 respectively so can I assume that 150A i.e average of 3 will be the 3phase load currents and remaining will be 1phase currents. Please clarify my doubt.   4
why we step down voltage level from 33kv to 11kv and 11kv to 415v.Instead we can step down voltage from 33kv to 415v directly using single transformer. HCL 10
Between rotating armature type and rotating field type arrangements which one is adopted for large rated alternators and DC generators.Why there is difference in the choice?   1
if we have to design a small transformer of rating 1 kva or 1 mva , how can we design it?   1
There are 2 motors without name plate and terminal but one is DC motor and another is induction motor.How one can identify which one is DC and which one is AC motor?   6
what its mean 'inverter based technology' ? if we talk about refrigerators, splits ACs etc how it helps to produce & keep more coolness and chilled atmosphere ?   1
what is rotating transformer? what is the uses of it?i mean applicaitons?   4
 
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