What is Transformer Rating?

What is Transformer Rating?

Transformer Rating Definition

Transformer rating is defined as the voltage and current specified for operation, expressed in VA (Volt-Amps).

Importance of Cooling

The effectiveness of the cooling system impacts the transformer’s rating, with better cooling allowing a higher rating.

Loss Types

• Constant losses or core losses – These depend on V

• Variable losses or ohmic (I2R) losses – These depend on I

Power Factor Independence

The transformer’s rating in kVA is independent of the load’s power factor since losses do not depend on it.

Apparent Power Rating in kVA

Transformers are rated in kVA, not kW, to account for the combination of voltage and current without considering power factor.