Answer / r

the losses depends purely on voltage and current . that is
core loss is proportional to voltage and cu loss is
proportional to current, thats why the tr is rated in KVA
not in KW

Answer / s s nanal

Transformer is AC Static Inductive M/c where there are no
moving parts.Hence frictional losses are nil.In AC M/cs
power factor i.e.cosine of angle between voltage & current
is important.The relation between KVA & KW is given by
following formula. KVA = KW /P.F. or KW = KVA X P.F. This
angle between Voltage & current decides actual power
available.Transformer being highly inductive m/c power
factor is never = 1.Hence actual KW available is always
less than KVA. Hence X'mers are rated in KVA.

Answer / ashok

because of there are two type of loses in transformer one is iron loss and second is copper lose.iron lose is proportional to the voltage and copper lose is depends upon current hence transformer losses is measured in KVA.

Answer / vivek

and yes , one more thing the output of a transformer has no
realtion to the power factor of the load , ie the active and
reactive loading of a transformer can be done in any range
as long as the combined active and reactive loading does not
exceed the max current limit . this will also give you the
answer to why motors are rated in KW , as the power output
of a motor is dependent on only the active power it consumes
.....

Answer / suneetha

in oder machines lik motors also core loss is prop to
voltage n cu loss is prop to current..but dey are rated in
kw nly...y s t so???

Answer / sathish.b

the losses depends purely on voltage and current . that is
core loss is proportional to voltage and cu loss is
proportional to current, thats why the tr is rated in KVA
not in KW

Answer / vivek

the limiting factor in transformer loading is voltage and
current , so , specifying a transformer in KVA with a given
primary and secondry voltage gives he maximum loading
current in both the sides. coupled with the transformer base
impedence , it also gives the regulation and losses at any
load .

Answer / engr. tariq

KW = KVA * PF

According to this formula since power factor depends on
load or load current( Apparent /Real power ) therefore we
can say that the rating of transformer is in KVA.

Answer / mijibar rohaman

kva=kw/p.f
as pf never more than unity,so it can be varied with the
angle between voltage and current.so kw alsom may be
varied.as a result tranformer is rated as kva.

Answer / hyderabad

yes

What is maximum permissible length of cable from transformer (33kV/0.433kV) HT side to HT panel which contain VCB? In which standard i shall get this information.

6 Answers   MSEB,

THE 40 MW OF POWER FOR 220 V III PHASE POWER CONNECTION REQUIRES HOW MANY KVA POWEER REQUIREMENTS

7 Answers   Chartered Accountant,

what is the difference between earthed cables and unearthed cables

2 Answers   Bhel,

After completing iti in electrician, how can i get certificate of electrical supervisor? What ia requirements. For it?

0 Answers  

What is Neutral Transformer? what is the use of this?

4 Answers  

what is the exact direction of current? as we know current travels from higher potential to lower potential,so if we take battery +ve to -ve implies current direction is from positive terminal to negative terminal.,whereas electrons flow from negative to positive as they are attracted by positive ions.current will be the plow of charge but not flow of positive ions.please clarify my doubt friends.

2 Answers  

Please tell me the power flow from pmg to main rotor of an alternator (Including AVR unit)?

0 Answers   Hindalco,

How to select the proper VSD to operate high inertial load

0 Answers  

why 3 phase is preferred than 1 phase?

4 Answers   Infosys,

11 KV Power cable end earth connection insulation got burned wht is the reson pl give the resons

2 Answers  

how a resistor resists to flow the current?how an inductor oppses the sudden change in current?how a capacitor opposes a DC voltage.

0 Answers   Hindustan Unilever Limited,

What is the purpose of shunt trip in ACB function?

1 Answers