why transformer ratings in kva?
- 99 Answers
- 211227 Views
- Bhel, College School Exams Tests, DOW, Emco, Esab, GE, KCP, PGCVL, Sodexo, TCS, vtps, Wipro, I also Faced
- E-Mail Answers
Answer Posted / pradyumna chandra panda
Why the motors are rated in KW and transformers are rated in
KVA?
Ans . Motor is a consuming device it consume the power
(wt) so it is rated in KW. But the
Transformer is a static device which transfers
the power (Apparent power) from the
Generating point to the user. Apparent power is
the product of voltage and current
I.e. Increase voltage with decrease current and
decrease voltage with increase
current. Power factor of the load does not
affect apparent power it affect the Active
Power.
Active power is the real power which the transformer
gives. Transformer should not be rated on the base of
Active power (KW) which is variable because the power factor
of the load is not knows before which to be connected across
the transformer.
Reactive power Apparent power (k)
KVA
VI sin Q k
Kw
Q q
Active power VI cos Q
Active power is equal to apparent power at resistivity load
where power factor is unit at cos Q is equal to zero degree.
Active power is decrease power where cos Q (not fi) is
increase
Therefore in simple we can say due to unknown power factor
transformer and generator are rated in KVA.
Hint – we know cos FI is the value of cos Q i.e. apparent
power/ active power
| Is This Answer Correct ? | 3 Yes | 0 No |
Post New Answer View All Answers
I want formula to calculate cable size as per load given in length & amp. I searched many sites but didn't right answer. Please reply me asap.
According to conduit size which size wiring & how many wires can we provide wires in conduit & how can we select conduit size accordingly?
What are the different methodes for calculating the short circuit Current?
Is there a standard depth of gravel fill in Substation Switchyard? Please give a design/drawing. Thank you.
Benifits of 3ph 4 wire metering over 3ph 3 wire
What is mean by spike arrester(Voltage Operated)
If VFD is On but no starting commond on it. so how many outpout voltages of VFD
How to know any size of cable if there are not written on cable? Answer must be theurical not by experience.
I have motor of 3 H.P. How i found the rating of capacitor use in it in single phase motor..???
I don't understand why when we connect high voltage source in DC to electronic motor , we must add capacitor and resistor in parallel ? (I know that we use capacitor because we want to absorb the current that in the first second electronic motor in opposed with current course produce. ) what are the feature of Resistor and in such situation ?
What are the disadvantages of thermal power plant?
Cb closed condition if there is a tcs fail whether cb will trip or not
why need to be maintain power factor for industrial customer?
what is meant by tranformer impedance?
what is the voltage rating of chiller unit sensors
