**Contents**show

## 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.

## 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?

**Transformer**

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