The Basics of Electrical Distribution Systems

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An Electrical Power System is a comprehensive term that consists of three major parts: a generation unit, transmission unit, and distribution unit. Distribution units as a final stage of the system are responsible for the distribution of power for local use.

Why do providers of MEP design services need a thorough understanding of this?

MEP Engineering involves the design of distribution boards and breaker panels. These will determine the required power to operate electrical components and control systems. 

Two Types of Distribution Systems

When we use electricity, it goes through two different distribution lines before we can use it. Distribution lines that have a higher voltage are called primaries or primary distribution lines. As for those lines that have a lower voltage, they are called secondaries or secondary distribution lines. Let’s take a look at their differences.

Primary Distribution System

This system consists of feeders that distribute power from substations to transformers. At the distribution substation, the feeder begins with a feeder breaker. Usually, feeders leave the substation in ducts and then send them to a nearby pole. Industrial facilities are the only ones who can feed directly from the transmission line.

Average consumers are usually connected to a transformer where the voltage is at a usable level. The primary distribution comes in three types of distribution networks, but the main types are Network and Radial.


This system is basically like a tree. Consumers are only connected on one line to the source of supply.  This connection is typically used in rural areas.


Network systems have parallel or multiple connections to the source of the power supply. This is usually used in dense urban areas, or areas that are load-sensitive.

Though radial systems only have one connection, modern-day radial systems do have backup options. As a company that provides MEP design services, we know that each system is important in specific areas.

Secondary Distribution System

The parameters that contain the electricity’s properties are not limited to current and voltages. Frequency is the third important property of electricity. There are two common frequencies in which electricity is produced, in 50 or 60 Hz. This low volt of electricity is then delivered to consumers as a single-phase of electric power.

Secondary systems are always operated at a low voltage level to provide enough power to most home appliances. Modern secondaries are usually functioning at an AC-rated voltage of 100-120 volts or 230-240 volts in various areas.

Electrical distribution systems are designed to provide the consumers with reliable and high-quality power. With these basics, we can all conclude that electricity contribution is not an easy task and requires professional MEP engineering. It also requires an immense amount of calculation and proper understanding of the area being powered.

When it comes to providing and understanding the basics of electrical distribution systems, the expert team at Source2Load Engineering and Consulting fully understands these systems without any problem.