Interested to Buy Any Domain ? << Click Here >> for more details...
Why Transformer in KVA?
- 41 Answers
- 91021 Views
- APCPDCL, Apollo Power, College School Exams Tests, Electrical Tech, Hitech, HP, L&T, MDL, Oil and Gas Jobs, TATA, I also Faced
- E-Mail Answers
Answer Posted / pankaj rajput
The copper loss of a Transformer depends on current i.e.
I^2 R and the iron loss depends on voltage. Hence the total
losses depends on volt-ampere (VA) and not on phase angle
between voltage & current.
Therefor the losses in a transformer are independent of
power factor which is cosine of angle between voltage &
current.
That's why the rating of transformers is in KVA and not in
kW.
Now coming to Efficiency of a transformer: Yes it depends
on power factor of load. Because the
Efficiency = Output/Input
= (Input - Losses) / Input
= 1 - (Losses / Input)
= 1 - [Losses / (Vs * Is * Cos phi + Losses)]
Efficiency is inverted V curve (Y-scale) and the peak of
curve appears between 50-60% load (X-scale)for various load
power factors. Efficiency increases as the power factor
increases.
| Is This Answer Correct ? | 23 Yes | 6 No |
Post New Answer View All Answers
iam preparing for rrb section engineer post in electrical branch.suggest the right textbook for my reference.fromwhere i will get the previous q.papers?
why ct's&pt'S out put called as burden,why compelsary short ckt the secondary of ct's while removing the burden?
What is meant by stator?
The moisture in air will condense at
What is installed in PAC that is control the humidity
I just purchased a 4 position cam switch to be used to operate a 3-speed blower motor. The motor is a 10 amp motor and has 3 wires that are used to control speed. The cam switch was rated at 660V 20 amps but when I received it, I noticed that it has AC-15 operational current rating (Ie) of 4/5 amps. If I am reading the label correctly. the 4/5 amps is related to 440v/220V (Ue). Other ratings are AC-3: 5.5A, AC2: 7.5A and AC-4: 1.5A. My questions are 1) Is it safe to use this switch with the motor I have 2) what is the difference between the 20 amp Ith ratting and the Ie operational ratings?
in indoor type circuit breakers why only the corner breaker trips specially during cold season. What is the reason.
hi all i like to know vat is power plot in control systems also i want to know abt latest trends in electrical & electronics
Can we use Ccapacitive voltage transformer directly for metering purpose?
Whata are the types of Cables?
1.what is the difference between transformer differential and busbar differential.2)why we are using 2 slope for trafo diif and 1 slope for busbar diff.3)what is the purpose of metrosil and stabilizing resistor in high impedance relay circuit.4)how metrosil reduce the peak volage.5)what is the funtion of stabilizing resistor
In Dyn11 power transformer if any one of the 3 phases connected to earth in star connected side then please explain effect of the current flow in delta connected side of transformer.(In this case if one phase is shorted to ground in star connected side then we observe the current flow in two phases only not three phases in delta connected primary side. Please explain why it is so?)
Bimetal strip used in overload relay what is that,which types of material used for that & percentage.
what is the standard values(Megger test) of resistances between L&N,L&E and N&E for a system on IEE regulations?
how to i get B licence,i am completed BE electircal and electronics engineering.i want to konw the proceduure to get b licence
