What Are 3 Phase Transformers?

11th July 2016

Why Are They Used? Transmitting electricity at high current levels and low voltage is an expensive process. Transformers play a crucial role in electrical distribution systems. Utility companies distribute electricity to large areas using high voltages. When this electricity gets to the end point (your office or factory), it is converted to lower voltage with the help of transformers. Transformers are used to convert the voltage from the utility company to the voltage required to operate equipment in your premises.

What is Three Phase Power? Before we can understand 3 phase transformers, it’s essential to understand how the power companies generate electricity. The utility company has generators that produce electricity by rotating three windings or coils through a magnetic field. Each coil or winding is displaced at 120 degrees from each other. As these coils rotate through the magnetic field, they produce power, which is transmitted on three lines, which is nothing but 3-phase power.

Three phase transformers should have three windings or coils conjoined in the right sequence so as to match the incoming power, and eventually transform the high voltage produce by the utility company to the level of voltage required in the premises.

What Are 3 Phase Transformers? Transformers are essentially of two kinds, single phase and three phase. When we say single phase transformers, it means that you only need one conductor (consisting of one primary and one secondary winding) to transform the voltage received from the utility company. Three phase transformers consist of three conductors. That is, they contain three sets of primary and secondary windings.

It’s as if three single phase transformers share a joined core. Three phase transformers are much more economical when it comes to supplying large load. Be it the industrial sector, power generation or power distribution, three phase transformers are the preferred choice.

Advantages of 3 Phase Transformers

  • They use much less conductor material when compared for transmitting power to single phase transformers at the same voltage. For this reason, they cost much less to build when compared to a bank of single phase transformers.
  • Since they use less material, they are also much lighter and compact, and weigh less.
  • A three phase transformer makes use of three conductors to carry current, which results in a much more balanced load thereby providing a lot more power than single phase transformers.
  • Three phase transformers are highly reliable and operate smoothly and efficiently too.
  • If and when a fault occurs in any coil of a 3 phase transformer, the other two coils can be used to serve the 3 phase load. This is not possible in case of single phase transformers. This makes three phase transformers much more reliable.
  • Quick to assemble.
  • Easy to install and repair.
  • It’s possible to supply single phase power supply on a 3 phase transformer, but it’s not possible to supply three phase power from a single phase transformer.

How to Size Transformers? So how do you determine transformer size? Calculate voltage, power and current. You will require ‘turns ratio’, total load and primary voltage of the transformer to carry out this calculation. Secondary voltage is essentially primary voltage divided by ‘turns ratio’. Secondary current can be calculated by multiplying current ratio by the turn ratio. The power the transformer receives will be more than the power coming out of the transformer.

Choose AM Transformers AM Transformers are leading manufacturers of 3 phase transformers in UK. Manufactured to the highest standards, we bring to you high quality 3 phase transformers. We manufacturer 3 phase transformers of all sizes (up to 750 KVA) customised to your requirements. Customers trust us for our fast delivery, excellent prices and high quality products. Call us for custom designed transformers that meet your requirements.