Electric Power Distribution Engineering, 3rd Edition

Chapter 3

Application of Distribution Transformers

Now that I’m almost up the ladder,I should, no doubt, be feeling gladder,It is quite fine, the view and such,If just it didn’t shake so much.

Richard Armour

3.1 Introduction

In general, distribution transformers are used to reduce primary system voltages (2.4–34.5 kV) to utilization voltages (120–600 V). Table 3.1 gives standard transformer capacity and voltage ratings according to ANSI Standard C57.12.20-1964 for single-phase distribution transformers. Other voltages are also available, for example, 2400 × 7200, which is used on a 2400 V system that is to be changed later to 7200 V.

Table 3.1

Standard Transformer Kilovoltamperes and Voltages

Kilovoltamperes		High Voltages		Low Voltages ...