Why a transformer is rated in kVA and not in kW??
Answers were Sorted based on User's Feedback
Answer / md. samiul islam
In Transformer, there are two types of losses, One is copper
loss (Cu Loss) which depends on current and other is iron
loss which depends on the voltage. Hence total transformer
loss depends upon the Volt-Ampere (VA, so it is independent
of load power factor. This is why a transformer is rated in
KVA instead of KW.
Is This Answer Correct ? | 22 Yes | 2 No |
Answer / naresh kumar
In t/f there are two losse ,first loss is Cupper loos and
second is iron loss,which get current & Voltage
respectively.There is no any power factor that why we
measure the t/f in VA not in watt.So transformer is rated
in KVA not in KW.
Is This Answer Correct ? | 18 Yes | 5 No |
Answer / ashok bhatnagar
The current drawn by a transformer depends on the load
connected in the secondary. If the load cneected is a
resistive load the majority of current drawn is in pahse
with the supply voltage and transformer operates at near
unity power factor. In this case transformer supplies kw
nearly equal to its kva input. However if a inductive load
like motor is connected it draws lagging current and
operates at lower power factor. In this case trasformer
supplies lower kw as compared the kva drawn. Thus
powerfactor of a trasnformer depends on type of load
connected and hence it can not have defined kw rating. That
is why transformers are rated in KVA and not KW
Is This Answer Correct ? | 10 Yes | 1 No |
Answer / r sanjay
Tranformer windings are insulated copper wires and are
designed to carry a particular amount of current(depending
on the size/diameter/cross-sectional area of the
wire).Beyond this current the windings will get damaged due
to overheat. The current that flows through these windings
is dependent on the load connected to the secondary of the
transformer. Both active and reactive portions of the
current contribute to the current flowing through the
transformer windings. Thus the total current is the
limiting factor. Moreover, the insulation of the
transformer windings determine the max voltage that it can
support. Thus, the voltage and the current determine the
capacity of the transformer. this product in KVA defines
the transformer capacity. KWatts is the active power and is
lower than the KVA by a factor called pf(power factor).
Where Watts = Volts X Amperes X pf.
Is This Answer Correct ? | 2 Yes | 0 No |
Answer / karna
In Transformer Copper losses in current, Iron losses in
voltage , the total losses depends upon VA not in KW. And
there is no Phase angle between voltage and current. That's
Why we are Transformer rating in KVA( Killo Volt Amp)
Is This Answer Correct ? | 0 Yes | 0 No |
Answer / gurunadharao
Transformer design is independent of powrfactor, what about the distribution load is..thats y we are used capacitor bank in Lt load
Is This Answer Correct ? | 0 Yes | 0 No |
Answer / guest
P=VI
V=VOLTAGE v
I=CURRENT A
POWER IS THE PRODUCT OF VOLTAGE AND CURRENT
Is This Answer Correct ? | 1 Yes | 2 No |
Answer / guest
becouse t/f is a machine that transform the voltage. that
is not a power cosumable device. and we did not know how
types load to connect to the t/f means
resistive ,capicitive or inductive type so we have not
value of power factor.
Is This Answer Correct ? | 0 Yes | 3 No |
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