why transformer ratings in kva?

Answer Posted / gk

The difference is that, even though both are electrical
equipments, transformer is considered as a power source
while the Induction motor is considered as a load.

In the case of a power source, you cannot predict the type
of load (resistive, Capacitive or Inductive) that will be
connected to it. Hence the actual usable capacity rating
depends on the power factor of the load.

Power = Voltage x Current x Power Factor

If the load is resistive, PF is 1 (unity) and if the load
is inductive, it will be less than unity.

In the second case (Load), the motor manufacturer gives the
rated voltage and full load current taking into account the
power factor.

Thumb Rule - all AC power sources - Generators,
Transformers, UPS etc. are rated in KVA and all loads are
rated in Watt or Kilowatt.

Is This Answer Correct ?    248 Yes 42 No



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