Understanding Transformers and kVA Ratings

These flashcards cover key concepts about transformers, kVA ratings, and how to calculate them based on the provided lecture notes.

What do transformers use instead of Watts for their ratings?

Transformers are rated in kVA (kilo-Volt-Amps) instead of Watts.

Why are transformers considered inductive loads?

Transformers use the principle of mutual induction, which introduces an inductive part to the circuit.

What type of power do transformers produce in addition to true power?

Transformers also produce reactive power due to induction.

How is kVA related to the power rating of a transformer?

The kVA rating determines the current that a transformer can deliver to a load without overheating.

What is the formula for calculating kVA?

The formula for calculating kVA is the product of Voltage (V) and Current (A), divided by 1000.

What are the secondary values used in the example problem for calculating kVA?

The secondary voltage is 25V and the secondary current is 150A.

What is the kVA rating calculated for the transformer in the example?

The kVA rating calculated for the transformer in the example is 3.75 kVA.

Why is it important to remember that transformers are not 100% efficient?

Because they do not just produce true power; they also induce reactive power.

What does the kVA rating being the same for primary and secondary windings imply?

It implies that you can use either primary (Vp, Ip) or secondary (Vs, Is) values for calculations without a difference.

What theme should you look for in problems asking to calculate kVA?

Look for a scenario that provides additional context and information to extract the necessary values.