EARTHING (GROUNDING) SYSTEMS

PROTECTING PEOPLE, PROPERTY AND PLACES OVERVIEW Electrical Earthing System Design

PTSG Electrical Services Ltd. is the largest of the four business divisions of Premier Technical Services Group – the UK’s leading provider of specialist services for the Soil Resistivity construction and FM sectors. Surveys

We are the UK’s market leader in the design, installation and testing of lightning Our range protection systems. With a wide portfolio of assets across multiple industry sectors, we of services Soil Modelling are also the natural choice for every kind of and Analysis earthing system requirement, from design includes, but is and installation to test, repair and upgrade. not limited to:

Touch and Step Potential Calculations

Electrical Earthing System Testing

2 3 Construction

Utilities rail (light and heavy) Sectors we routinely Defence (MOD) work in:

Energy (including green technologies)

IT/data sectors

4 5 ACCREDITATIONS

All design work carried out by PTSG’s skilled team is in accordance with BSEN 50522:2010 (earthing of power installations exceeding 1kV). TS 41- 24 Issue 2, November 2018 (guidelines for the design, installation, testing and maintenance of main earthing systems in substations). Other design specifications can be provided. All designs are completed using CDEGS (Current, Distribution, Electromagnetic interference, Grounding and Soil Structure Analysis) design software. This is an extremely powerful software suite designed to accurately analyse a variety of electromagnetic related problems involving electric networks.

All inspection and testing provided by PTSG is carried out in accordance with BS7430:2011 +A1:2015, the code of practice for protective earthing of electrical installations.

6 7 WHY SPECIALIST EARTHING IS SO IMPORTANT The three main reasons for specialist earthing are To protect people from the danger of electrical shock, All of PTSG’s services make buildings, systems and equipment which can cause death safer and more efficient for their users. Earthing is the creation of an alternative path for the flow of fault or excessive currents safely to ground. It is an integral part of any electrical system and essential in keeping both people and equipment safe. To provide voltage stabilisation – earthing removes the guesswork, helping to ensure no circuits overload or blow up

To provide overload protection – in instances of excessive power surges, earthing can prevent devices and appliances from getting fried, saving data and equipment

8 9 An earthing system consists of three main parts: Diseworth Newcastle Wishaw Office Edinburgh Office Chadderton Office Head Office UK Distribution Centre Unit 6C Netherdale Road 78/82 Carnethie Street Unit 6 West Acre Richardson 1 11-14 Flemming Court Unit 4 Netherton Ind. Est. Rosewell Whitegate Business Centre The Walnut Yard The Town Hall Chambers Whistler Drive Sterling Business Park Wishaw Midlothian Jardine Way Gelscoe Lane High Street East Glasshoughton Carr Wood Road North Lanarkshire EH24 9AW Chadderton Diseworth Wallsend Castleford Castleford ML2 0ER OL9 9JT DE74 2AN NE28 7AT WF10 5HW WF10 4PS Tel: +44 (0) 1314 401 991 Tel: +44 (0) 1698 374101 Telephone: 0161 871 2970 Phone: 01926 485080 Phone: 0191 500 9758 [email protected] Tel: +44 (0) 1977 668 771 Fax: +44 (0) 1698 355025 www.ptsg.co.uk Fax: +44 (0) 1977 668 772

Manchester Office Alma House Sheffield Unit 4 Rotunda Business Centre Grimshaw Lane Unit 34 Thorncliffe Middleton Jessops Riverside Chapeltown Manchester 800 Brightside Lane Sheffield M24 1GQ Sheffield S9 2RX S35 2PG Tel: +44 (0) 161 655 3000 Tel: 0114 256 1197 Tel: 0114 257 2080 Fax: +44 (0) 161 655 3001 Fax: 0114 242 2440 Fax: 0114 240 2171

Nottingham Office Ground Bury Office A conductor Unit 16 & 17 Unit 1 Bridge Trading Estate Warrington H2O Business Park Bolton Road electrodes, usually Suite 128 The White House Lakeview Drive that connects Bury Warwick Wilderspool Business Park Annesley BL8 2AQ University Road Greenhall Avenue Nottingham Off Gibbet Hill Lane Relatively low copper rods, Warrington NG15 0HT the electrode to Telephone: 0800 917 3065 Warwick WA4 6HL CV4 7AL resistance solid penetrate into the Tel: +44 (0) 1159 758 820 the body of the Phone: 01925 438012 Phone: 01926 485080 ground to achieve equipment meant Stoke Office Unit 43 lower resistance Essex (Witham) Office to be earthed Parkhouse Indl Estate East Swanbridge Industrial Park Winpenny Road Black Croft Road Newcastle Under Lyme Staffordshire ST5 7RH Witham Essex Kidderminster Office Tel: +44 (0) 1782 565 797 CM8 3YN MCF Complex Tel: +44 (0)1376 503330 Fax: +44 (0) 1782 564 260 New Road Kidderminster Worcestershire DY10 1AQ Maidstone Office Unit 12, Viewpoint Tel: +44 (0) 1562 829565 Bridgend Boxley Road Fax: +44 (0) 1562 829286 Maidstone Unit 48 Apollo Business Village Kent Heol Persondy ME14 2DZ Aberkenfig Bridgend Tel: +44 (0)800 043 1974 Ω CF32 9TF Phone: 02920 029717

Gatwick The Beehive Building Abingdon Beehive Ring Road 9E Nuffield Trade Park Gatwick Airport Nuffield Way West Sussex Abingdon RH6 OPA OX14 1RL Tel: +44 (0) 845 074 2758 Before installing an earthing system, the first design step is Phone: 01235 862456 Fax: 01235 834450 to measure the resistance of the earth. Many different things

Exeter need to be consideration, such as the resistivity of the soil, Little Bridge Business Park Bournemouth Heathrow London Office Norbury Office London City London Oil Mill Lane Hello House Building 16699, Old Met Office The Grove 2a Norbury Crescent 219 Long Lane 320 New North Road the level of moisture in soil, the number of rods connected in Clyst St Mary 135 Somerford Road Northern Perimeter Road West North Road Norbury Bermondsey Hainault Exeter Christchurch Heathrow Airport South Ockendon London London London EX5 1AU BH23 3PY Hounslow RM15 6SS SW16 4JU SE1 4PB IG6 3ES parallel and the depth of electrodes under the ground. TW6 2EQ Phone: 01392 874455 Phone: 01202 007721 Tel: +44 (0) 1977 668 771 Tel: +44 (0) 2086 799 323 Tel: +44 (0) 845 074 2758 Phone: 0207 256 8035 Fax: 01392 875546 Phone: 0208 564 8752 Fax: +44 (0) 1977 668 772 Fax: 0207 236 0655 Using PTSG’s electrical experts is the best way to ensure an earthing solution that is appropriate to the installation. 10 January 2018 to April 2019 Wales SPECIALIST EARTHING PTSG Electrical Services Ltd. was tasked with carrying out on-site testing and inspection of the HV and Primary LV earthing arrangements. This FOR BUSINESS CASE STUDY included ATEX hazardous areas to ensure that the functional and safety criteria within BS 7430 and BS EN 50522, i.e. permissible stress, touch and step potential limits were not exceeded.

Verification of an existing HV and Primary The work involved the measurement of site-based equipment, along LV Earthing arrangement at a well-known with soil resistivity surveys and the production of an overall design chemical business assessment including associated calculations, to ensure compliance with the above standards. Following completion of the testing, the development of a risk-based, time-bound action plan to resolve any non-compliances that were identified. After completion of the assessment/calculations, the relevant inspection, test and maintenance documentation was produced to reflect the calculated maximum allowable earth resistance values complete with recommended pass and fail criteria.

From the start, working through historic site data and site information to the completion of the ITM documentation, PTSG Electrical Services Specialist Earthing Division completed the work on budget and within the allotted time frame. xxxxx xxx xxx xxxx xxxxxxxxx xxxxxx “The work involved the measurement of site-based equipment, along with soil xxxxx xxx xxx xxxx resistivity surveys ” xxxxxxxxx xxxxxx Dec 2017 – April 2018 South East SPECIALIST EARTHING The Specialist Earthing and Power division of PTSG Electrical Services Ltd. was contracted to produce an earthing study to assess the earth FOR LOGISITCS CASE STUDY potential rise and associated touch and step potential values across a large site wide HV 11kV/LV distribution network. The original work scope was for a single location, which was expanded to include the existing site performance; this resulted in additional installation Installation of new HV distribution work and testing and the development of the site-wide works. equipment site-wide for a large logistics company in the UK Soil resistivity surveys were undertaken across the site, along with the fall of potential measurements of existing substation locations. This information was used to finalise the earthing study with the production of design reports showing the Earth Potential Rise (EPR) along with detailed touch and step potential profiles for each of the substation locations.

Detailed earthing layout drawings, confirming conductor types, sizes and positions in addition to detailed technical drawings, showing how the earthing system was to be configured, were produced. The installation of the above earthing was undertaken by PTSG Electrical Services Ltd, with final verification and certification being produced.

xxxxx xxx xxx xxxx “The project was undertaken xxxxxxxxx xxxxxx to a very tight schedule and the works were completed ahead of programme and within budget xxxxx xxx xxx xxxx ” xxxxxxxxx xxxxxx Dec 2018 – April 2019 London SPECIALIST EARTHING PTSG Specialist Earthing was contracted to develop an outline earthing design for a railway substation and operating plant project, into a buildable, CASE STUDY site-specific earthing design solution. The project contained multiple contractors working on differing items of plant and equipment, all of FOR RAIL which required a common detailed earthing solution to be produced, delivering a safe and effective earthing system. Development of a detailed design and The project required the production of detailed design documents production of a buildable solution within with supporting calculations, detailed installation drawings and Railway infrastructure supporting technical details. The production of risk assessments and industry-specific documentation were required to enable the client to approve the scheme.

The testing and commissioning of the installation and the production of industry specific documentation were provided. The detailed design was delivered within a short timescale, incorporating multiple contractor requirements all delivered to client requirements.

Simon Greenwood was the Company Responsible Engineer (CRE) on this project.

xxxxx xxx xxx xxxx “The detailed design was xxxxxxxxx xxxxxx delivered within a short timescale, incorporating multiple contractor requirements xxxxx xxx xxx xxxx ” xxxxxxxxx xxxxxx Feb – Apr 2019 Midlands SPECIALIST EARTHING A detailed substation earthing study was previously completed on site, requiring close co-operation with a regional DNO (District Network FOR CONSTRUCTION CASE STUDY Operator) – as a result of a unique connection configuration.

Development of detailed design HV PTSG Specialist Earthing and Power was contracted to develop an earthing solution for the new build CHP plant. The installation work combined heating and power plant (food was undertaken by a third party, with the design development industry) requiring co-operation with other professionals.

The design was completed ensuring that both industry- and client-specific requirements were adhered to. The final testing, commissioning and certification of a compliant installation were also undertaken by PTSG.

The design documentation was produced working in collaboration with others and enabled a safe, cost-effective and deliverable solution to be achieved.

“The design was completed ensuring that both industry- and xxxxx xxx xxx xxxx client-specific requirements xxxxxxxxx xxxxxx were adhered to ”

xxxxx xxx xxx xxxx xxxxxxxxx xxxxxx www ptsg.co.uk 01977 668 771 [email protected] @ptsgltd