Why transformer rating in kva

Why Transformers r Rated in kVA, Not in kW?

Why Transformers unit rated in KVA?

Transformer rating is expressed in kVA, not in kW.

Rating of a tool or the alternative electrical machine reflects its load carrying capability whereas not heating.

Temperature rise (a major threat to insulation) arises thanks to internal loss at intervals the machine.

An important accept the design and operation of electrical machines is that the relation between the fundamental quantity of the insulation and operational temperature of the machine.

Therefore, temperature rise succeeding from the losses may be a very important accept the rating of a machine.

There ar a try of varieties of losses in associate degree passing transformer;

1. Copper Losses
2. Iron Losses or Core Losses or Insulation Losses

Copper losses ( I²R) unit variable losses that depend upon Current passing through device windings whereas Iron Losses or Core Losses or Insulation Losses depends on Voltage.
We know that copper loss in associate degree passing device depends on current and iron loss depends on voltage.
Therefore, the overall loss in associate degree passing device depends on the facility unit product entirely and not on the aim between voltage and current i.e., it's freelance of the
load power issue.
So the device is supposed for rated voltage (iron loss) and rated current (copper loss).
We can’t predict the facility issue whereas developing with the machine, as a results of the power issue depends upon the load that varies from time to time.

When a manufacturer makes a tool, UPS etc., they have no set up of the sort of load which will be used & consequently they're going to entirely rate the device according
to its most current output that the conductors will safely carry (at unity Power Factor) & the insulation rating of the conductors (voltage & temperature).

Thanks for Reading.

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