# How do you find the primary current of a transformer?

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## How do you find the primary current of a transformer?

If for some reason you need a larger transformer to operate appliances, you still divide the wattage by the voltage to find the current. For a 120-volt primary, 2000-watt transformer, divide 2000 by 120 for the current (2000 Watts /120 volts =16.67 amps). For a 240-volt, 3000-watt transformer, the current is 12.5 amps.

## How is current related to turns ratio?

In other words, the number of turns and the current in the primary and secondary windings are related by an inverse proportion. Then the ratio between the primary and the secondary currents is 100A-to-5A, or 20:1. In other words, the primary current is 20 times greater than the secondary current.

## What is the formula of step-up transformer?

The currents Ip and Is in the primary and secondary coils are related by IsIp=NpNs I s I p = N p N s . A step-up transformer increases voltage and decreases current, whereas a step-down transformer decreases voltage and increases current.

## How do you calculate the number of turns on a transformer?

Windings and Wire You now need to determine the number of turns that will be required for each secondary winding. The first step is to use formula 3 (N(s) = V(s) / V(p) x N(p)) to determine the turns for a perfect transformer. This number then needs to be increased to account for the losses in the coils.

## How to calculate the turns ratio of a transformer?

The transformer turns ratio n is calculated as: Vp is the primary winding voltage. Vs is the secondary winding voltage. Calculate the secondary full load current of a a 200 kVA, 11 kV to 420 V, step down transformer. Calculate the secondary full load current of a a 200 kVA, 11 kV to 420 V, step down transformer.

## How to calculate the primary and secondary current of a transformer?

Transformer current calculations: Transformer turns ratio, V(primary) * I(Primary) = V(secondary) * I(secondary) The primary voltage is equal to the product of the secondary voltage and primary current divided by secondary current.

## How to calculate the full load current and turns ratio?

The secondary winding full load current Is is calculated as: S is the transformer rating. Vs is the secondary winding voltage. How to calculate transformer turns ratio? The transformer turns ratio n is calculated as: Vp is the primary winding voltage. Vs is the secondary winding voltage.

## How to calculate the current of a 50 kva transformer?

Example: A 50 kVA single-phase transformer has a 4000 V primary, and a 400 V secondary. Assuming an ideal transformer, determine (a) the primary and secondary full-load currents, (b) the transformer turns ratio. Primary full-load current, I 1 = (50 × 1000 / 4000) = 12.5 A