What is the secondary output of a 45 kVA transformer?

How many output amps is a 45 kVA transformer?

Three Phase Transformer

KVA 208V 240V
45 125 108
50 139 120
60 167 145
75 208 181

How do you calculate current in a secondary transformer?

In other words, i1/i2 = V2/V1. For example, if the current and voltage drop through the secondary coil is 3 amps and 10 volts, and the voltage drop through the primary coil is 5 volts, then the current through the primary coil is 10/5 * 3 = 6 amps. So the secondary has less voltage and more current.

How do you calculate the amp output of a transformer?

Divide the wattage by the voltage. For example, if you have a 300-watt lighting transformer and you are going to hook it up to a standard 120-volt socket, divide 300 by 120. The transformer will draw 2.5 amps of current.

What size breaker do I need for a 45 kVA transformer?

For a 45kVA transformer, 125A×1.25=156A, so use a 175A protection device.

How do you calculate the output voltage of a transformer?

Divide the number of secondary windings by the number of primary windings, and multiply the source voltage by this ratio. This will give you the output voltage.

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How do you calculate secondary phase voltage?

Primary phase voltage = 2,400 divided by 1.73 = 1,387 V. Secondary phase voltage = 1,387 divided by 10 = 139 V. Secondary line voltage = 139 V multiplied by 1.73 = 240 V.

What is the secondary voltage of a transformer?

Secondary voltage is the coil winding supplying the output voltage. The output voltage of a transformer varies some with varying load resistances, even with a constant voltage input.

What is the secondary current?

(Elec.) a momentary current induced in a closed circuit by a current of electricity passing through the same or a contiguous circuit at the beginning and also at the end of the passage of the primary current.

How do you calculate secondary full load current?


  1. Transformer full load current = kVA / (1.732 x Volt)
  2. Transformer full load current = 1000 / (1.73 2× 480) = 1203 Amp.
  3. Short circuit current at TC secondary (Isc) = Transformer full load current / Impedance.
  4. Short circuit current at TC secondary = 1203 / 5.75 = 20919 Amp.