menu Log in Contact About Updates Prices FAQ Home

Transformer calculator -full load current and turns ratio

The transformer calculator calculates the primary and secondary full load current, and turns, ratio of a single or 3-phase transformer.
Phase

Transformer rating
 
Primary voltage (V)

Secondary voltage (V)

See Also

Parameters

How to calculate transformer primary full load current?

The primary winding full load current Ip is calculated as:

\( I_{p}= \dfrac{S}{\sqrt{3} V_{p}} \)

Where,

How to calculate transformer secondary full load current?

The secondary winding full load current Is is calculated as:

\( I_{s}= \dfrac{S}{\sqrt{3} V_{s}} \)

Where,

How to calculate transformer turns ratio?

The transformer turns ratio n is calculated as:

\( n = \dfrac{ V_{p} }{ V_{s} } \), Where,

Example 1: Calculate transformer full load current

Calculate the secondary full load current of a a 200 kVA, 11 kV to 420 V, step down transformer.

\( I_{s}= \dfrac{200000}{\sqrt{3} \cdot 420} \)

\( I_{s}= 275 \textrm{ A} \)

Example 2: Calculate transformer turns ratio

Calculate the secondary full load current of a a 200 kVA, 11 kV to 420 V, step down transformer.

\( n = \dfrac{11000}{420} \)

\( n = 26.2 \)