Answer / manish kumar meena

in transformer cu loss depends on current and iron loss on
voltage.Hence total loss depends on volt-ampere(VA) and not
on phase angle between voltage and current.Thats is why
rating of transformer is in KVA.

Answer / annakka

the power factor of the loads connected in transformer are
not same.

Answer / sanket patil

THE POWER FACTOR OF A TRANSFORMER FEEDING THE LOAD
DEPENDS ON THE NATURE OF THE LOAD; HENCE THE ACTIVE(P) AND
REACTIVE(Q) POWERS SUPPLIED BY THE TRANSFORMER MAY CHANGE
FOR A FIXED APPEARENT POWER(S).
HENCE THE TRANSFORMER RATING IS ALWAYS SPECIFIED IN KVA
AND NOT IN KW OR KVAR AS THEY CHANGE AS PER THE LOAD
CONNECTED TO THE TRANSFORMER.

Answer / mukund

The KW rating is assigned for equipments that consumes power with certain leading/lagging between Voltage and Current depending on the nature of the load (A resistive load is more towards V&I in sync whereas an inductive load has V&I lagging and A capacitive load featuring V&I leading). A transformer is supposed to only transfer the power, although there are inherent losses while doing the same, however for practical purposes, eliminating transformer's own consumption, a transformer is rated on its original purpose with the simple V&I relationship disregarding the Cos-phi factor (the lead/lag of V&I). Hope I am making some sense

Answer / mahantesh

IN TRANSFORMER THERE ARE MANY LOSSES AS CORE LOSS ,OHMIC
LOSS WINDAGE N FRICTIONAL LOSS ETC.....THE CORE LOSSES ARE
PROPORTIONAL TO VOLTAGE AND OHMIC LOSSES ARE PROPORTIONAL TO
CURRENT THAT'S THE MAIN REASON WHY TRANSFORMER ATING IS IN KVA.

Answer / robert harper (ee tech)

KW=work
VA=ability to do work, no power factor considered.

Answer / chandrashekhar sahu

The rating of any machine depends on the factor that always
remain same at any condition. In case of a transformer the
multiplication of voltage and current for primary and
secondary side remain the same at all load conditions. so
the transformer rating denoted as VA.

why auto transformer connected in star?

1 Answers  

Why Dyn11 Transformer is selected for distribution transformer?

3 Answers   JK Associates, MSETCL Maharashtra State Electricity Transmission Co Ltd,

what is the equation of insulating resistance of motor???

1 Answers   Birla,

CBCT selection

0 Answers  

what is current

8 Answers   NTPC,

Why earthing transformer used in Distribution Sub-Station?

3 Answers  

One Township having 850 house and each house load is 2.2KW single phase & 5HP 3 Phase motors of 10 Nos .Who can calculate 11 KV transformer capacity .dilip_bhasker@yahoo.co.in

1 Answers  

What is the Nyquist criterion regarding control systems?

0 Answers   GE,

sir pls send the je exam - 2008 and other model question papers..

0 Answers  

hwat type of motor is used in thermal gas turbine hydro nuclear power plants and why

0 Answers   Bhel,

what is inverter and converter

0 Answers   Hindustan Syringes and Medical Devices,

as we see that in our country the power rating for transmission is always rated in multiple of 11 like 11kv,33kv,66kv132kv. So i want to know wht is reason or logic here.

2 Answers