Answer / jyotirmaya patra

In distribution system, generally the p.f. taken in account
is 0.8. So the maximum kw load available is 1500x0.8=1200kw.

For safest condition the diversity factor should be taken
into account is 80%. So the maximum 960kw (80% of 1200kw) of
load is allowed on a 1500KVA transformer.

Answer / ashutosh + mukesh

In distribution system, generally the p.f. taken in account
is 0.8
Beacuse our transformer is 1500KVA.
SO = 0.8
FROM FORMULA:- KW = KVA*P.F.
so KW = 1500*0.8

KW = 1200
So our transformer upto 100% load= 1200KW

Beacuse we take maximum 80% load on Transformer for safety
so: =1200* 80/100
=960kw

Answer / pardeep

actually first of all we calculate the load and after that
we would be able to slect the transformer. ok any how if
you have 1500kva transformer you can take 1200kw to 1350 kw.
its depends upon the dversity factor. how much you will
take.i know only this answer if anybody else has some other
please correct me.

Answer / muhammad qasim

Dear,

Transformers are designed for p.f. 0.8

Even if you make your power factor unity (which may sometime
disturb your source), you can not load transformer up to
100% of its capacity. It will raise threat to your costly
machines. Being good engineer, you should not let your
consumer exceed loading your transformer more than 90 % that
becomes 1350 kW (if p.f. is unity) and 1100kw (if p.f. is 0.8).

Regards

Answer / sayed asef

Dear its very simple
first just convert this 1500 KVA into KW at assumin PF 0.8
which equal to 1200 KW then Calculate the Ampere by the
Below Formula
P = 1.73 X V x I X PF
then you will get the Ampere,and then you can easily find
out the load by ammeter or any how you know abt 1200KW.
so you can put the load 1200 KW but being good engineer
dont put 100 % load on your transformer ,its better if you
put 80 or 90 % load.
thanks
regds
sayed asef s ali

Answer / sai seddy

In transformer, the current in line with voltage,so here
there is no cosine angle between the voltage and
current.but Practically some angle present in the voltage
and current.so the power factor should be more than 0.9.
KVA = 1500
P.F = 0.9
KW = 1500*09
=1350KW.
For Safe working allowable = 80% of rated of rated voltage.
Safest power = 1350*0.8
= 1080 KW

Answer / walid

IF PF=1
Max KW=KVA=1500
IF PF < 1
kw < kva ( <1500)

Answer / usha chandel

From the given transformer ,the max. power we can take
depend on the load p.f which we connect with the
tranaformer.As the pf has max value of 1,so at unity pf we
can take 1500 Kw from this transformer or the max power
from the transformer we can take is 1500 Kw

Answer / jun domdom

The answer will depend on the load itself.
Practically, they used 80% once you get the power by obtaining the process done as the number one answer above, it is correct.
But considering the entire load is diffrent.
You have to consider the losses, harmonic, heat etc.
But in my previous experience I thought it will shut down when I reached the 80% maximum load out of open delta 75kva transformer. My current reading is 265A and still increasing.
I'm waiting for shut down and burn of the transformer,
But it does not happen.
I reached even 455A and my heart is about to burst rather than the transformer.
So therefore transformer can withstand the maximum load up to 133% or even more.

Answer / anton

Most transformers are at there best efficiency at 90 - 100% load therefore if you are being billed for your energy use on the HV side you don't want to have a transformer way to big and lightly loaded, most transformers will handle 100% overloads for short periods without dropping there output voltage, supply authorities would rather see a transformer intermittently overloaded than way oversized and massive losses when not very loaded, the reduction in lifespan from intermittent overloading is well and truly paid for in savings of the losses a larger transformer would have over its life

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