AM18 Medium voltage distribution (2023)

This Applications Manual on medium voltage distribution has been produced to help fill the gap in electrical knowledge in respect of how to safely employ medium voltage for the distribution of electrical power.

Our aim is to provide an understanding of a number of key aspects at different design and construction stages of a medium voltage (11 kV) power distribution system to buildings. Consideration is given to system design and to the selection and erection of equipment, including the associated practical aspects.

It is intended that this Applications Manual will be used by practitioners in conjunction with established international wiring standards and relevant codes of practice. It will also be of interest to designers and authorities who, while not directly concerned with the design or installation of electrical systems, must understand the advice offered to them by specialists.

Further, the manual should be of value to those who wish to enhance their knowledge of electrical power and building services engineering.

Medium voltage distribution is a specialised area of power engineering. This manual is in five parts:

• AM18.1: Methods
• AM18.2: Equipment
• AM18.3: Protection
• AM18.4: Fault calculations
• AM18.5: Grading

For specific detail refer to the specific web pages for AM18.1-AM18.5.

The parts of this Applications Manual will not cover high voltage systems (that is, those using power supply voltages greater than 33 kV). This also means that we will not go into any detail regarding transmission and distribution at these voltages nor specialised power applications within the industry (such as the protection of power factor correction capacitors, harmonic snubber circuits, high voltage direct current, high power static conversion, battery storage or smart grids). For information regarding possible solutions for these applications, it is best to refer to manufacturers’ literature.