uploaded by Chris Dodds - Thorne & Derrick (Sales & Marketing Manager)
Earlier today, Thorne & Derrick the UK specialist distributor of LV, MV & HV Cable Jointing, Earthing, Substation & Electrical Eqpt welcomed Mick Fowler (Business Development Engineer – PB Weir) to their new offices in Chester-le-Street, County Durham UK.
Since 1985, T&D have developed a strong reputation for supplying UK DNO’s and NERS accredited Independent Connection Providers (ICPs) with an extensive range of LV MV HV Electrical Equipment including arc flash clothing and protection to utility workers.
T&D service UK and global businesses involved in cable installations, cable jointing, substation, overhead line and electrical construction at LV, 11kV, 33kV and EHV.
PB Weir are the globally recognised designer, manufacturer and supplier of temporary portable earthing, voltage detectors and Buchholz Relays.
T&D met PB Weir following several recent project successes including supplying portable earthing systems to Hornsea Project 1, Scottish Power and a number of National Grid approved contractors working on projects at HV High Voltage and EHV Extra High Voltage.
Chris Dodds comments, “the commercial and technical support provided to Thorne & Derrick by PB Weir is excellent – in 2017 Thorne & Derrick experienced a record intake of new business, new customers and new account openings. That set the stage perfectly for 2018. Now our half-year sales targets and goals for 2018 have been met we look forward to introducing PB Weir to our existing and potential customers over the remainder of the year”.
Pictured left to right: Mick Fowler (PB Weir), Chris Dodds, Martin Wigham and David Tinning (T&D Sales Engineers).
😀 Thorne & Derrick Announce Distribution Agreement & Contract With Nexans
➡ See how Thorne & Derrick working with PB Weir can supply standard and develop customer bespoke Portable Earthing Equipment for all substation earthing applications – this includes Line End Clamps, Earth End Clamps, Aluflex Leads, Operating Poles and Connectors.
Since 1985, T&D have established an international reputation based on SERVICE | INTEGRITY | TRUST.
Cable Blowers | Cable Lubricant | Duct Rods | Cable Socks | Cable Jacks | Cable Rollers | Cable Protection Covers MV HV | Cable Joints MV HV | Duct Sealing
Contact us for 3M Electrical, ABB, Alroc, AN Wallis, CATU Electrical, Cembre, Centriforce, CMP, CSD, Elastimold, Ellis Patents, Emtelle, Euromold, Filoform , Furse, Lucy Electric & Zodion, Nexans, Pfisterer, PB Weir, Polypipe, Prysmian, Roxtec, Sicame, WT Henley.
Thorne & Derrick invite you to join LinkedIn’s largest LV-HV Electrical Discussion Group : Low & High Voltage Power, Cabling, Jointing & Electricals. Discussion subjects include cable installations, earthing, cable jointing, substation earthing, overhead line and electrical construction at LV, 11kV, 33kV and EHV. Network, engage and promote your profile, company or products with over 10,000 influencers.
Images: ABB
by Chris Dodds T&D - estimated reading time 6 minutes
Thorne & Derrick International are distributors for the ABB Furse and AN Wallis range of Earthing & Lightning Protection Systems – this includes earth rods, earth bars, earth tapes and a full supporting range of accessories to comprise the complete earthing system for electricity transmission and distribution systems.
The copper products are used typically to provide electricity substation earthing to medium/high voltage grids containing electrical infrastructure, cables, switchgear and transformers. Furthermore, it is usual for all exposed and normally un-energised metalwork inside the substation perimeter, including doors, staircases, ventilation ducts, cable supports etc to be be bonded to the main earth grid to avoid any potential differences between different items of metalwork.
Guidelines and policies vary according to the Distribution Network Operator – specialist contractors using modern earthing techniques compliant with relevant British and international standards, including BS 7430:2011+A1:2015 Code of Practice For Earthing and IEEE80-2000 Guide for Safety in AC Substation Grounding should be employed to calculate specific substation earthing requirements.
A final design of the earthing system can only be undertaken when sufficient knowledge is available of the proposed physical and electrical requirements of the substation – as an absolute minimum the earthing system desginer must have knowledge of:
The specification for fixed earthing systems within EHV, HV, HV/MV and LV substations also applied to terminal towers adjacent to substations and cable sealing end compounds, pole mounted transformer or air-break switch disconnector installations and pole mounted reclosers with ground level control.
➡ View our complete range of Substation Earthing products including substation and overhead line earth clamps, telescopic sticks and portable earthing kits – see also Exothermic Welding.
Full range of bare copper, printed and covered earth tapes are available
Example – Substation Earthing 11kV. Image: SPE Electrical Ltd
Earthing products and systems can be supplied by T&D for all substation voltages:
T&D provide expert technical support, competitive prices and delivery from stock for substation earthing projects – all earthing products are available to meet the design criteria and construction specification of the earthing systems for substations and equipment for 33kV and 132kV substations.
This include copper earth tapes with typical dimensions 32mm x 4, 40mm x 6mm, 50mm x 4mm and 50mm x 6mm.
With respect to high voltage earthing applications in the power utility sector the following items would normally be earthed or bonded to the main earth grid:
It is usual for critical items such as medium/high voltage transformer tanks and terminal towers to have duplicate connections to the main earth grid.
Pictured above is a diagram showing the typical layout of a high voltage GRP electricity substation distributing 11kV power – an outer ring of 70sqmm copper earthing conductor plus 4 earth rods of standard depth are shown with a 10 metre tail in the HV cable trench accompanied by a layout for the concrete rebar. Here, the HV substation is contained within a GRP enclosure with potential touch and step voltage risks.
Earth tapes are available stamped with the UK DNO ownership details to discourage copper metal theft – earth tapes printed “National Grid Property” are also available.
Full range of copperbond earth rods, couplings and driving studs are available for grid and primary substation earthing depending upon the calculated fault level.
Touch Voltage
The potential on the surface of the soil near a copper earth rod during the time that fault current flows. If a person were to touch a rod (or any exposed metalwork connected to it), then the potential difference experienced between hands and feet is termed the touch voltage. Touch voltages are calculated assuming that the feet of the person are 1 metre away from the metalwork being touched. Touch voltages are normally reduced by using potential grading electrodes.
Step Voltage
Potential differences are established on the surface of the soil whilst fault current is flowing. Step voltage in a particular direction is defined as the potential difference between two points a metre part. Step potentials can be reduced by using potential grading copper electrodes or installation electrodes, such as copper earth rods, at a greater soil depth.
Transfer Potential
A potential rise of an earthing system caused by a current flowing to earth, transferred by means of a connected conductor (eg metallic sheath or pipe), which enters a substation area, with little or no potential rise relative to reference earth, and which is not connected to earth in that area. This results in a potential difference occurring between the conductor and its surroundings at the remote position.
Substation earthing systems are the victim of operational and intentional damage – copper theft is rife and earthing maintenance work is often identified during routine site checks and inspection. Earth faults can be weekly occurrences on primary substations supplying extended high voltage rural overhead line networks. During these maintenance tasks there is serious risk of injury or even fatal electric shock when working on depleted or damaged earthing systems – specialist electrical safety equipment including insulated sticks, poles or rods, portable earth shorting leads, earthing clamps (substation or line-end), insulating footwear (shoes or boots) and insulating gloves depending on the voltage class of the substation earthing system.
T&D distribute a full range CATU Electrical Safety equipment including Arc Flash Kits, Insulating Boots & Safety Shoes and Voltage Detectors
All images courtesy: Ian Forster (EHV Site Manager)
Fig.1 3 x Copper earth cables connected to main aluminium substation earth tape
Fig.2 Copper earth tape connected to main aluminium earth tape
Fig.3 Aluminium to aluminium tape connection
View the Earthing Products below for further information and technical details.
Published 28 Nov 2025
Request a Quote Call Us: +44 (0)191 410 4292 Stokbord cable protection covers are rigid HDPE protection boards designed to be installed above buried cables in trenches. They are manufactured and designed by Centriforce to provide strong mechanical protection...
Published 28 Nov 2025
Restoring transformer termination integrity with LoviSil When a major site recently experienced a fault on an 11kV transformer termination, the challenge was clear: restore the system quickly, safely and without the expense/disruption of full PILC cable replacement. Upon investigation,...
