MV Power Distribution Design


1-day course

CPD Credit: 7 hours, C1 / C2

Course Overview

The aim of this course is to give electrical engineers currently involved in LV distribution design an understanding of the principle aspects of MV distribution design. 

This course provides an introduction to the design of MV distribution systems for building including the selection of the MV switchgear, transformers and cables.

Learning Objectives

At the end of the course attendees will:

Be aware of the principle regulations in Ireland in relation to MV distribution

Understand how to select the most appropriate switchgear system for a particular application

Understand the function of CTs, VTs, protection relays, battery alarm tripping units and other ancillary equipment

Understand the factors involved in selection and sizing an MV cable


Part 1 - MV Distribution - Regulations

ESB Networks: - Conditions Governing Connection to the Distribution System

National Wiring Rules for Installations over 1 kV ac

Part 2 - MV Switchgear

Circuit Breakers - Vacuum v SF6 and AIS v GIS

Current Transformers (CTs) and Voltage Transformers (VTs)

Protective Relays, types, settings, ANSI Codes

Earthing arrangements

Battery alarm tripping units

Part 3 – MV/LV Power Transformers

Power transformers ratings and selection to suit load

Oil filled vs. cast resin types

Transformer protection, alarm and trip signalling

Part 4 - MV Cables

Structure of MV cables, terminations etc.

Single core versus 3 core MV cables

Sizing of MV cables

Who Should Attend?

This course will benefit electrical engineers and contractors already involved in the supply chain of LV power distribution systems for buildings.

Trainer’s Profile

Brendan Dervan is a Chartered Engineer with over 40 years’ experience in all aspects of mechanical and electrical building services including design, installation, commissioning and maintenance. After completing an electrical apprenticeship in 1982 he went on to study electrical engineering in DIT.

He has worked in M&E consultancy at senior engineer / director level since 1990. In 1999 he started his own M&E consultancy, Dervan Engineering Consultants (DEC), which merged with Cundall in 2016. His Company provided M&E consultancy and project management services to a diverse range of clients in both the public and private sectors. In 2013, Brendan completed an MSc in Energy Management with TU Dublin. His thesis researched the improvement of energy efficiency in existing data centres.


  • Alan Homan, Arup: “As an electrical consultant, I found the course very informative, and I got clarity on some things or buzz-words that will hugely benefit me now and going forward.”
  • Wilson Costa, Amazon: “Fantastic course”
  • Rory Yates, CBS Consulting Engineers: “Great material, well presented, experienced and knowledgeable presenter. Excellent CPD”
  • “Well delivered to the point on topics in description. Proper insightful answers to questions based upon real life scenarios.”
  • “Excellent course with actual material tailored to specifics for Ireland with is rare in the Medium Voltage sector.”
  • “I found the course very informative and it covered a number of important MV design and installation related issues.” 

Please contact the Team for further information on scheduled course dates and In-Company options. You can reach us by phone: 01 665 1305 or email