Distribution Transformers

The purpose of a distribution transformer is to reduce the primary voltage of the electric distribution system to the utilization voltage serving the customer.

A distribution transformer is a static device constructed with two or more windings used to transfer alternating current electric power by electromagnetic induction from one circuit to another at the same frequency but with different values of voltage and current.

Types according to use and application:

Pole-mounted Transformers
    10 to 63kVA, single phase and 25 to 500kVA, three phase

Ground-mounted Transformers
    300 to 1500kVA, 11 and 22kV, integrated and/or industrial styles complete with HV and/or LV swirtchgear.

3 Main parts in the distribution transformer:

    1. Coils/Winding - where incoming alternate current (through primary winding) generates magnetic flux, which in turn develop a magnetic field feeding back a secondary winding

    2. Magnetic core - allowing transfer of magnetic field generated by primary winding to secondary winding by principle of magnetic induction
These two parts are known as the active parts

    3. Tank - serving as a mechanical package to protect active parts, as s holding vessel for transformer oil used for cooling and insulation ans bushing (plus auxiliary equipment where available)