Calculating Your Transformer Needs

transformer pic

Calculating Your Transformer Needs

Published under Transformer Basics
When purchasing a transformer for a new building or power-heavy project, it is important that you know what you are doing. Getting a transformer that is not big enough to handle your power needs could be a big and expensive problem. Getting a transformer that is bigger than what you need can be a waste of money as well. Below is a quick explanation of how to find out your power needs so you can make an informed decision.

To determine the size of the transformer you need, determine the following requirements for your transformer:

1. Load Voltage

The load voltage, or secondary voltage, is the voltage that is needed to operate the load.

2. Load Current/Amps

Single-Phase has two lines of AC (alternating current) power. Three-Phase has three lines of AC power, with each line 120 degrees out of phase with the other two.

3. Line Voltage

The line voltage, or primary voltage, is the voltage that comes from the source. The size of a transformer is determined by the KVA (kilo volt amperes) of the load.

Next, determine if your application is single-phase or three-phase, and use the corresponding formula below.

The KVA of the transformer should be equal to or greater than the KVA of the load to handle present requirements and to account for future expansion.

Tags: Calulation How Big? Transformer