How to calculate Primary current of any transformer in just 2 steps!

How to calculate Primary current of any transformer in just 2 steps! 1024 576 Gaurav J

In this tutorial, I’ll explain 2 simple steps from which you can calculate primary current of any transformer. Transformer can be 1 phase or 3 phase. So, let’s get started.

Step 1

Get the following details
  • KVA/MVA rating of a transformer (For this example, assume KVA = 100)
  • Primary Voltage of transformer (Assume 11kV)

Step 2

Put the details obtained in Step 1 in the following formula

For 3 phase transformers

I_{Primary}={{KVA\times 1000}\over \sqrt3\times V_{Primary}}

Let’s put the values we assumed in Step 1 in above formula.

I_{Primary}={{100\times 1000}\over\sqrt3\times 11000}

I_{Primary}=5.25 A

For 1 phase transformers

I_{Primary}={{KVA\times 1000}\over \ V_{Primary}}

So, these are the two simple steps you can use to calculate the primary current of any single phase or three phase transformer.

In case, you are interested is knowing the 3 simple steps to calculate the short circuit current of any transformer, click here.

Gaurav J

Electrical Engineer. Content Creator. Currently working with a High & Extra High Voltage Switchgear Industry.

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