Earthing

Copper Earthing Tapes For Down Conductors – Some General Considerations

Copper Earthing Tapes – Bare & Covered Copper Tapes

• Uploaded by Chris Dodds - Thorne & Derrick Sales & Marketing Manager
  
  

Copper Earthing Tapes

Thorne & Derrick International, a leading stockist and distributor of copper earthing tapes manufactured by AN Wallis and ABB Furse provide an overview of the role and relationship of earth tapes with respect to the design of Lightning Protection Systems in accordance with British Standard BS EN 62305.

Down conductors

Some general considerations for the use of copper earthing tapes as down conductors are as follows unless the Earthing & Lightning Protection System (LPS) is isolated:

• There should be at least two down conductors around the building
• The down conductors should be as equally spaced as possible
• Copper earth tape as down conductors should be installed at exposed corners of building
• Down conductors can be fixed to any wall or surface which is non-combustible, if the surface is combustible refer to BS EN 62305 for guidance
• Down conductors must not be sited in gutters or down pipes
• The down conductor ideally will follow the shortest and most direct path to earth
• The down conductor should as far as possible be straight and vertical
• Wherever possible avoid any re-entrant loops where this is not possible the separation distance shown in Figure 22 Is required as a minimum, if this cannot be achieved another design for the down conductor system should be considered
• A test joint should be fitted on each down conductor to enable disconnection from the earth network and provide access for earth resistance measurement and maintenance

The bottom 3 metres of the down conductor should be protected within a metal guard or PVC covering at least 3mm thick to deter vandalism and copper earthing tapes theft Figure 21. The test clamp should be fixed above the capping wherever possible Figure 21.

Down Conductor should be protected by metal guard of PVC covering at least 3mm thick to deter vandalism

If the air termination is a metal rod on a non conductive mast, at least one down conductor is needed for each mast.

No additional down conductors are required for masts made of metal or interconnected reinforcing steel.

If the air termination consists of one or more catenary wires at least one down conductor is needed at each supporting structure.

Positioning the down conductors

There should be multiple down conductors following the shortest possible path to earth via the conductive copper EARTH tapes.

Typical values of the distance between down conductors, subject to architectural and practical constraints are given in the table below.

Table 5.4 – Typical down conductor spacing’s and distance between ring conductors

It may not be practically possible to space the down conductors exactly as required, so the spacing’s can be adjusted by ±20% but the average spacing of all down conductors must conform to the typical distances for the class of LPS.

If it is not possible to place down conductors at a side or part side of the building the down conductors that should be on that side should be placed as additional down conductors compensating for the other sides. The distance between the installed down conductors should not be less than one-third of the required down-conductor distances dependent upon the class of LPS.

Equipotential bonding to conducting parts of the structure should be performed according to BS EN 62305-3, 6.2.

The distance between the down-conductor and the internal services must satisfy the distance requirements covered in the table above.

If the separation distance required to avoid dangerous sparking between the down conductor and the internal services cannot be satisfied, the number of down conductors should be increased until the required separation distance is met.

Protection on a Cantilevered Structure

There is a risk when the down conductor goes into a cantilever that a strike could flash over to this risk the separation distance, h in metres, should satisfy the the person standing underneath 2.5 as shown in figure 22. To reduce mtrs following conditions.

H > 2.5 + S

S – Is the separation distance in metres calculated.

2.5 – represents the height of a typical person with their hand in the air.

Using natural components as down conductors

The natural components can be used as down conductors provided the components comply with the requirements of BS EN 62305.

The natural components can be used provided there is electrical continuity, where the joints are tightly bolted they can be considered as electrically continuous Figure 23.

Natural components as down conductors

The facade elements, profile rails and metallic sub-constructions of facades can be used provided their dimensions conform to the requirements for down conductors and metal sheets or metal pipes, not less than 0.5mm thick.

If the metal façade of the building is to be used as the down conductor then BS 62305 offers specific guidance.

Each overlapping vertical joint at each down-conductor position should be bridged by flexible metal strapping. See Figure 24.

Overlapping vertical joint bridged by flexible metal strapping

Connections between the sheet metal panels should have a minimum contact surface area of 50 sqmm and be capable of be capable of withstanding the mechanical forces of a lightning discharge.

If access to the rear of the façade is not possible and the only type of fixing available for connections between facade sheets and the air termination or down-conductor tapes is pop rivets then these should be at least four 5mm diameter rivets and used on a length of conductor, such as copper earth tape, a minimum of 20mm long. (C.S.A or conductor (connection component) min 50 sqmm). 

Down conductors not using the

natural components of the building

Where down conductors are installed on the building not using the natural components then consideration needs to be given to the separation distance between the internal columns and internal partition walls with conductive parts.

If these conductive columns and partitions do not satisfy the separation distance conditions they must be connected to the air termination system at roof level and to the earthing network at ground level.

What Is BS EN 62305-3:2011?

Part 3 of EN 62305 sets out all the requirements needed to protect buildings and structures against physical damage by implementing a lighting protection system (LPS). It also looks at how to protect humans and animals (living beings) against injury if they are close to an LPS. By defining these safety measures, this standard helps you to minimise damage, invest in the right electrical protection equipment and maximise hazard prevention in buildings.

Thorne & Derrick International

Contact us to discuss all your Substation Earthing, Cable Jointing & Terminating requirements for the installation of LV MV HV cables, copper earthing tapes and infrastructure including switchgear, transformers and electrical equipment up to 33kV.

Product Categories: Duct Seals | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Protection | Cable Jointing Tools | Cable Pulling | Earthing | Feeder Pillars | Cable Joints LV | Joints & Terminations MV HV 

Largest UK Stocks Of Copper Earthing Tapes

Earth Rods | Earth Bars | Earth Mats | Earth Clamps – manufactured from high conductivity copper by AN Wallis and supplied by Thorne & Derrick

Tinned Copper Earth Bars – How To Specify The Correct Earth Bar

Earth Bars – manufactured from 50x6mm Tinned Hard Drawn Copper Bar

• Uploaded by Chris Dodds - Thorne & Derrick Sales & Marketing Manager

Earth Bars

Advantages & Applications Of Tinned Copper

The following article has been written to provide some basic advice and reasoning for the specification of Tinned v Standard Copper Earth Bars when designing earthing systems for LV MV HV building services and substation protection exposed to wet conditions during normal operation.

Copper is used in the manufacture of Earthing & Lightning Protection Systems due to the high thermal and electrical conductivity, ease of manufacture, high recyclability and good corrosion resistance of the material. Copper, a noble metal that occurs naturally in its elemental form, is almost totally impervious to corrosion from soils found worldwide.

But it would be misleading to infer that copper will not corrode.

Tinned copper is a type of copper coated with a thin layer of tin used to provide protection to earth bars against the tarnishing and corrosive effects of oxidisation, commonly referred to as rusting.

The thin layer of tin effectively shields the copper surface of the earth bar inhibiting oxidisation – preventing air from reacting with the copper in the presence of atmospheric moistures. Put simply – no air, no oxide, no corrosion.

The copper tinning process provides enhanced protection against climatic variations and atmospheric conditions without significant reduction in the functionality and electrical conductivity of the copper metal.

Oxidised copper surfaces display poor conductivity compared to clean and smooth tinned copper which prolongs the service life of the earth bar at comparatively low added-on cost.

Tinned copper is higher cost than non-tinned copper but provides extended service life and field performance compared to standard bare type copper especially in wet condition installations.

These types of earth bars are commonly specified and installed in outdoor locations in the water utility, marine and offshore industries where high levels of atmospheric corrosion caused by environmental factors and moisture levels such as rain, fog and condensation necessitate improved levels of corrosion protection. Outdoor air can act as an electrolyte because it contains a variety of components which can cause corrosion of any metal.

Tinned copper handles wet conditions, high temperatures and humidity to maintain the conductive integrity of the earth bar for electrical engineering applications.

AN Wallis manufacture both standard copper and tinned copper earth bars from 6 way up to 30 way on short lead times in standard, single link or twin-disconnection link design. Image: Wallis 6 Way Earth Bar.

Applications & Necessity Of Tinned Earth Bars

Earth bars are used to provide a convenient common earthing point for electrical installations requiring an Earthing & Lightning Protection System – copper earth bars are available with single or twin disconnecting links which means the earthing bars can be isolated for electrical testing.

Tinned copper earth bars could be used in external applications or where atmospheric conditions are more severe than normal i.e. high humidity or moisture content areas and marine and offshore saline atmospheres.

Tinning protects the copper and protects the earth bars from the formation of copper oxide, tin effectively prevents oxidation.

Earth bars are a standard, efficient and convenient way of providing a common earth point with integral disconnection links permitting safe electrical isolation for testing purposes in the switchroom.

Why Should Earth Bars Be Tinned?

Tin is a soft white metal which can easily be polished, scratch brushed or flow melted to provide a bright finish.

Tin is non-toxic and is not greatly affected by the organic acids. Sulphur compounds do not readily tarnish tin and it is not impaired by either air or water but reacts with hydrochloric acid to form stannous chloride.

Tin is one of the less susceptible metals to corrosion attack consequently tin-plated surfaces of copper earth bars are adequately protected against atmospheric corrosion and hence provides longer life when exposed to corrosive atmosphere installations.

In normal state unaffected by corrosion copper is a rich brown colour – pictured below is an instance of copper oxide (“greening”) showing advanced corrosion to underground earth tapes. Tinning of the earth tapes and copper conductors prevents “greening” of the copper surface – furthermore this copper run-off can be very corrosive to galvanised steel support structures on medium/high voltage substations.

Benefits of a Tinned Earth Bar

• Tinning a copper bar protects against atmospheric corrosion providing longer life when exposed to corrosive atmospheres
• Tinning protects the earth bar against the formation of copper oxide (oxidisation)
• Tinned earth bars are an excellent solution to extend longevity and have reasonably low resistance
• Used in external/outdoors applications or where atmospheric conditions are more severe and aggressive than normal i.e. high moisture content areas, high humidity in both onshore (eg water treatment works) or offshore (oil/gas platforms)

Pictured: Here a tinned AWG 4/0 stranded copper conductor is bolted to a galvanised steel flange of a support column on a high voltage substation. Note the high pressure compression fitting installed using hydraulic crimping tools and protective paint for added protection of the copper cable lugs and conductor against corrosion in above-ground outdoor applications.

➡ T&D together with Wallis can offer a bespoke design service for custom earth bars in both tinned and standard copper construction – sizing, number of cable terminations, fixing materials and bases can be tailored to comply with specific site requirements and drawings are available on request to ensure the earthing bars are suitable.

Earth Bars

The following range of Earth Bars without disconnection links are available in both standard copper and tinned copper versions:

Earth Bars With Single Disconnection Link

The following range of Earth Bars with single disconnection links are available in both standard copper and tinned copper versions:

Earth Bars With Twin Disconnection Links

The following range of Earth Bars with twin disconnection links are available in both standard copper and tinned copper versions:

Tin Plating Services For The Electrical & Electronics Industry

The following comments have been kindly provided by Ian Molyneaux of Karas Plating Ltd – the UK’s most respected metal finishing company.

Bright Tin Plating

Tin is a silvery malleable metal that doesn’t get easily oxidized in air and is used to coat other metals to prevent corrosion. The electrical and electronics industry are heavily dependent on tin and tin alloy coatings for solderability most of which is done by electroplating. Tin plated metal is also used for food packaging giving the name to tin cans which are made mostly of steel.

Tin plating is used extensively in the electrical engineering industry to provide protection and to confer solderability. Tin electroplating is also widely used in manufacturing printed circuit boards (PCBs) and electronic components. Most electronic circuit components are made by soldering therefore the surfaces of the conductors being connected are coated in tin or a tin alloy aiding solderability. Additionally tin coating protects the components and connection from corrosion in aggressive atmospheres.

Tin is one of the easiest metals to electro deposit and one of the advantages of electroplating is that no limitation is imposed on the thickness of tin that can be applied. The required thickness can be attained by adjusting the bath parameters and time.

Tin is usually plated with a bright or matt finish. Bright tin is obtained from electroplating solutions containing brighteners, ie. organic additives causing formation of very fine grains of deposit. It has excellent cosmetic appearance.

Matt tin coatings are made in electrolytes with few grain refiners, but without brighteners. It has a dull appearance but the level of internal stresses in matt tin deposits are much less than in that of bright tin.

Bright Tin Plating

Dull Tin Plating

What is the difference between pure tin, bright tin, and matt tin?

Matt tin coatings are made in electrolytes without the addition of brighteners. Matt tin has a dull appearance, but the level of internal stresses in matt tin depositions is much lower than it is in bright tin depositions. Matt tin (in contrast to bright tin) is characterised by low whiskers growing, therefore, it is used in electronics.

Characteristics:

• a dull, semi-bright or satin-bright appearance
• disperse reflectivity
• existence of grains with an average size in the range of a few microns
• the deposit is free of the co-deposited brighteners found in bright tin plating

Dull tin is ideal for electronic or precision components. Deposits give good solder ability even after heat or steam ageing.

Karas Plating can plate onto substrates of aluminium, copper and copper clad aluminium busbars in both bright and dull tin.

Aluminium and copper clad aluminium busbar are generally used for reduction in weight and cost but both are easily tin plated

Contact Karas Plating Ltd : Call FREE today on: 0333 121 0151

AN Wallis Earthing Systems

Earthing and lightning protection manufactured by AN Wallis from high conductivity copper to BS EN 13601 is installed to protect buildings, overhead lines and medium/high voltage substations (MV-HV) against potentially catastrophic damage that can be caused by a lightning strike resulting in short circuiting of power networks.

The Wallis product range includes copper earth rods (solid copper, copper bond and stainless steel types), earth bars, earth tapes, earth clamps and aluminium tapes.

As the leading UK manufacturer of specialist Earthing and Lightning Protection Products, Wallis aims to provide the highest quality products without compromising on price or product performance in a safety critical application.

Quality assurance is integral to Wallis and to ensure this practice continues all earthing and lightning products are manufactured to stringent British and international standards.

Did You Know?

The Escondida copper mine in the Atacama Desert in Northern Chile is currently the world’s largest copper mine by reserve. The copper mine contained more than 32 million tonnes (Mt) of recoverable copper reserves at the end of 2012.

Further Reading

• Earth Tape – The Manufacture of Copper Earthing Tapes
• High Voltage Earthing & Grounding System Design Protecting Lives
• Copper Earthing Tape & Rods Protecting 33kV Substation & Transformer Bund
• Substation Earthing

Specialist Distributors: LV, MV & HV Cable Jointing, Substation & Electrical Eqpt

THORNE & DERRICK are national distributors of LV, MV & HV Cable Installation, Jointing, Duct Sealing, Earthing & Electrical Equipment – we service UK and global businesses involved in cable installations, substation, overhead line and the installation of medium/high voltage cable joints and terminations at LV, 11kV, 33kV and HV.

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, Polypipe, Prysmian, Roxtec, Sicame, WT Henley.

Earth Tape – The Manufacture of Copper Earthing Tapes

• uploaded by Chris Dodds - Thorne & Derrick Sales & Marketing Manager

Thorne & Derrick, are UK distributors, stockists and suppliers for AN Wallis Copper Earthing & Lightning Protection Systems – we were recently invited to visit their UK based location in Nottingham to understand and learn more about the manufacturing processes for copper earth tapes.

In this post we provide a selection of photographs taken during the AN Wallis factory tour – all copper earthing products are manufactured according to BSI ISO 9001:2008 and BSI OHSAS 18001:2007.

Since 1946 AN Wallis earthing products including earth tapes, earth rods, earth bars and earth mats manufactured from high conductivity copper have provided Earthing & Lightning Protection to LV MV HV Network Assets including primary/secondary substations, overhead line towers and power cable systems from 11kV/33kV up to 400kV.

Copper is a chemical element with symbol Cu (from Latin: cuprum) and atomic number 29 – a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a reddish-orange colour.

Earth Tape

A panoramic photograph of the AN Wallis production facility and factory where the earth tapes are manufactured from raw material into finished product – earthing tapes in bare copper form or with optional PVC covering and coloured are manufactured in a range of tape thicknesses and widths to achieve the required cross sectional area.

AN Wallis extensive copper feed stocks enable fast turnaround of major earthing project requirements for the global electrical power and utility industry – the 17,000 square feet manufacturing facility and extensive raw material copper holding ensures short lead times with “off the shelf” deliveries or quick turnaround manufacturing of all earth tapes.

1 Earth Tape Manufacturing

2 Raw Material Copper Feed Stocks

The raw material is supplied in solid copper conductor form – note the circular form of the feed stock which must be processed via the manufacturing machinery into the flat tape copper configuration. The Conform machine processes the copper into flat tape form and can be pre-set to optional dimensions. Weekly maintenance checks of the Conform machine include a general clean down, gearbox oil level check, hub cooling oil check, hub cooling water check and ensuring no water or hydraulic pipes are leaking.

3 Copper Earth Tapes

The circular copper conductor is fed from coil into the Conform machine – the conductor is conformed from circular to flat configuration producing a range of flat copper earth tapes from 12.5mm to 50mm widths. Computer software, such as CDEGS, can be used to calculate the power system earthing and grounding. Asset managers must calculate the level of site protection required depending on the cross section area of conductor required to provide effective earthing and lightning protection.

Methods to improve high voltage substation earthing and grounding with supporting measurements of earth resistance and computational models to simulate the possible Ground Potential Rise (GPR) due to injected current surges are a key consideration in providing effective lightning and earthing protection.

4 Processing Circular Form Copper Into Flat Earth Tape

Here the circular copper conductor is shown entering the Conform machine – in the “On” mode the motors and pumps feed the copper conductor into the Conformer via the machine wheel. Adjustable settings enable the manufacture of an extensive range of widths and thicknesses of copper tape.

5 Copper Earth Tapes

From this angle the photograph shows the complete AN Wallis manufacturing process for copper earth tape. The finished copper earth tape has now been conformed by machine to a flat tape design from the circular copper feed stock – this production run is manufacturing 50mm wide x 6mm thick copper earth tape, a UK utility standard for medium/high voltage substation earthing. The copper earth tape is annealed and produced with radiused edges for safe site handling by installers.

Wallis copper tapes are marked “Wallis U.K.- BS EN 13601”.

BS EN 13601 2013 is the current British standard covering Copper, Copper Alloys, Copper Rod, Bar & Wire for electrical purposes. The copper tapes are available embossed or inscribed with the client owners name as a copper theft deterrence measure.

6 Aluminium Earth Tapes

AN Wallis manufacture aluminium earth tape also at their Nottingham factory – lower cost than copper but with reduced conductivity the range of aluminium earth tapes are also available from stock.

7 Large UK Stocks Of Copper Earth Tapes

AN Wallis manufacture and hold the largest UK stocks of copper earth tapes – T&D, the UK’s largest supplier of AN Wallis products provide internationally competitive prices, delivery and technical support. A complete supporting range of copper clamps are available to secure and install the earth tapes to building infrastructures.

Full range of Earth Tapes

About AN Wallis

AN Wallis & Co Ltd has over 70 years experience in the design and manufacture of Lightning Protection, Earthing & Low Voltage Electronic Surge Protection products – a broad range of technical and earthing design services are provided including full design of structural lightning protection systems, design of substation earthing systems, soil resistivity tests, commissioning and project consultation.

AN Wallis has grown steadily and is a recognised world leader in the manufacture of quality Earthing, Lightning Protection, LV Surge Protection and Exothermic Welding products.

The Earthing Product range includes copper tape conductors, earth bars, copper earth plates, DC fixings clips, earth rods produced from solid copper, copper bond and stainless steel. Air terminals, earth rod clamps, inspection pits concrete and heavy duty polymer, earth rod seals, low resistance soil conditioning agents and also CU-NNECT exothermic welding products.

Thorne & Derrick distribute the complete range of Copper Earthing Products manufactured by AN Wallis to UK and overseas projects and competitive prices from extensive stocks – this includes earthing products for MV HV EHV substation projects including:

• Neasdon Depot Substation London Underground / Enterprise Rail
• Sleaford 132kV Substation EON / Enterprise
• Iver 132kV Substation/Windfarm SSE Scottish & Southern / Enterprise
• Swansea 400kV Substation National Grid / Electricity Alliance West
• Cardiff East 400kV Substation National Grid / Electricity Alliance West
• Sundon 400kV Substation National Grid / Electricity Alliance West

The products also provide Earthing & Lightning Protection for railway traction substations, distribution substations, overhead line towers, solar farms, STOR sites, data centres, hospitals and hazardous area sites.

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• Further Reading

  Underground Cable Photo Album 1890-1940 – Western Power Distribution (WPD)

  Copper Earthing Tape & Rods Protecting 33kV Substation & Transformer Bund

  Portable Earthing – Short Circuiting Kits For HV Substations & Overhead Lines

   

  Thorne & Derrick 

  

  Specialist Distributors: LV, MV & HV Cable Jointing, Substation & Electrical Eqpt

  THORNE & DERRICK are national distributors of LV, MV & HV Cable Installation, Jointing, Duct Sealing, Earthing & Electrical Equipment – we service UK and global businesses involved in cable installations, cable jointing, substation, overhead line and electrical construction at LV, 11kV, 33kV and EHV.

  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, Polypipe, Prysmian, Roxtec, Sicame, WT Henley.

High Voltage Earthing & Grounding System Design Protecting Lives

Earthing & Lightning Protection | Earth Tapes | Earth Rods | Earth Tapes |

Special Thanks To Ian Griffiths - Earthing System Design HV

In this Guest Blog from Ian Griffiths (GreyMatters Principal Partner) we learn how and why GreyMatters are revolutionising earthing system design and changing the status quo to protect our homes, businesses and industries from the harmful effects of uncontrolled releases of High Voltage HV electrical system power, including lightning strikes.

Below Ian discusses the successes of the last year at GreyMatters.

Lightning Strikes The Burj Khalifa

Well, 2017 was an exciting year for the team GreyMatters. So, at the end of 2016, we set goals on what we wanted to achieve in 2017. The biggest success story which is probably closest to my heart is smashing the previous year’s lives-protected by High Voltage Earthing/Grounding Design.

High Voltage Earthing

“Saving Lives” Explained

Above is a 2-minute explanation video on how we get to the lives protected numbers.

By-the-way, all rail sector work is ignored as this would add millions to the figures – which is great, but, for the purposes of catching the underlying trend for less populous work, it is not so helpful.

It’s an interesting dilemma, given that personally, my goal is to know that somewhere out there our work in Earthing/Grounding Design, has saved at least one person’s life.

Thorne & Derrick Largest UK Stocks Of Copper Earthing Tapes

And based on the HSE.gov.uk’s statistics for the UK, the rate of fatal injury per 100,000 workers is at 0.4 (2017); 6% (8) of those who sadly died last year (137) was as a result of electrocution, which means statistically in our population of 498,500 workers, we have still have got work to do! Given, we’ve influenced just under 1/8 of a worker’s life during 2017, we need to reach a figure closer to 4.16m workers to claim our first life saved.

Cumulatively, since we’ve been recording lives-protected, GreyMatters has recorded 1.4m which equates to a little over 1/3 of a life saved (statistically speaking of course).

Other Earthing News

Without wanting to sound too GreyMatters-centric – we upgraded the business systems to full UKAS accreditation for ISO9001, 14001 and OHSAS 18001. This is pretty unique as it makes GreyMatters the only independent specialist Earthing/Grounding Design Consultancy to be fully UKAS accredited – part of being a Top 1% specialist consultancy.

About GreyMatters

GreyMatters specialise in High Voltage Earthing System Design for earthing systems 1kV-765kV to meet EN 50522 and and international specifications, including 11kV, 33kV and 66kV power systems.

GreyMatters has been protecting critical assets and life from the harmful effects of high voltages and lightning strikes globally since 1995.

GreyMatters focus on high voltage electrical earthing system design, earthing measurement and surveys, lightning protection design, training and policy formulation.

Thorne & Derrick

THORNE & DERRICK are national distributors of LV, MV & HV Cable Installation, Jointing, Duct Sealing, Substation & Electrical Equipment – we service UK and global businesses involved in cable installations, cable jointing, substation earthing, overhead line and electrical construction at LV, 11kV, 33kV and EHV.

Since 1985, T&D have established an international reputation based on SERVICE | INTEGRITY | TRUST.

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, Polypipe, Prysmian, Roxtec, Sicame, WT Henley.

Invitation

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, cable jointing, substation, 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.

Copper Earthing Tape & Rods Protecting 33kV Substation & Transformer Bund

• Application: Using Copper Earthing Tapes, Rods & CADWELD To Earth 33kV Substation, Switchgear & Transformer
• Contractor: Power Jointing Services Ltd (Hampshire UK)  
• Image Courtesy: Robert Coleman LV HV Cable Jointer at Power Jointing Services Ltd
• Featured Product: Earthing & Lightning Protection MV HV

Copper Earthing Tapes & Earth Rods

33kV substation earthing is provided around the transformer bund and new building structure using copper earthing tapes, electrode rods and exothermic welding (CADWELDing) of the earth rods to tape – 50mm x 4mm earth tapes are installed as a ring and cross earthing design with 40mm x 4mm copper tape braised for additional stairs and walkway earthing.

The 33kV switchgear housing within the high voltage substation is earthed and bonded to a new transformer ring and Neutral Earth Resistors (NER). The copper tapes and earthing cables are shown connected to the 10 way earth bar. To achieve the required earth resistivity reading 3 x 1.2 metre length coupled copper earth rods were driven into the ground.

Driven earth rods are used to exploit lower resistivity ground conditions where present to reduce the earth potential rise (EPR) on substation earthing and lightning protection projects from 11kV/33kV up to 400kV.

Substation Earthing

Earthing of low, medium and high voltage electrical networks is critical to ensure safe and correct operation preventing and minimising against the consequences of a direct lightning strike to equipment and buswork within substations. UK DNO’s publish primary and secondary substation earthing designs for the application of earthing systems to HV and LV underground cables and overhead line networks, typically operating at 33kV, 20kV, 11kV, 6.6kV, 3kV and 2kV.

Similarly, the National Grid publish an Earthing Technical Specification for the lightning protection of transmission and distribution systems located in the busbar protection zone of the electricity grid operating at nominal voltages of 400kV, 275kV 132kV and 66kV. The general requirements of the substation earthing systems are compliance with technical standard EA TS 41-24 and British Standards BS EN 50522 and BS7430.

➡ Read our Blog about Substation Earthing

Earthing Standards

1. Energy Network Association (ENA) Technical Standard (TS) 41-24 (Substation Earthing) – the standard provides guidelines for the design, installation, testing and maintenance of main earthing systems in substations
2. BS EN 50522:2010 – the British Standard provides guidance for Earthing of Power Installations Exceeding 1kV a.c
3. BS 7430:2011+A1:2015 – the British Standard is a code of practice for Protective Earthing of Electrical Installations

Copper Earth Tape – the earthing tape 40mm x 4mm shown bonding to the existing medium/high voltage substation earth bar

Copper Earth Tape Dropper – 50mm x 4mm earth tape is shown earthing switch 1 of 3 on the 33kV distribution board

Earth Tapes – the 50mm x 4mm copper tapes are routed back to the rebar earths on the earth bar

Transformer Earthing – using 40mm x 4mm copper earthing tape on the 33kV high voltage transformer

Power Jointing Services Ltd

Power Jointing Services Ltd established in 2007 specialising in 33kV-400V electrical network construction, establishing industrial and commercial supplies, installing residential service connections and street lighting connections. Also: High voltage service alterations, cable fault finding and replacement of assets including transformers, low voltage distribution boards and link boxes.

Copper Earthing Tapes & Products

T&D provide competitive prices and fast delivery from stock for Earthing & Lightning Protection products including copper tapes, rods, electrodes, earth bars and ancillary items for low, medium and high voltage substations.

♦ Visit Substation Earthing for further information.

Thorne & Derrick Specialist Electrical Distributor

LV ♦ MV ♦ HV

T&D distribute the most extensive range of LV, MV & HV Cable Jointing, Terminating, Installation & Cable Pulling Equipment – we service UK and international clients working on underground cables, overhead lines, substations and electrical construction at LV, 11kV, 33kV and EHV transmission and distribution voltages.

• Key Products: MV-HV Cable Joints & Terminations, Cable Cleats, Duct Seals, Cable Transits, Exothermic Welding, Underground Cable Protection, Cable Jointing Tools, Feeder Pillars, Cable Ducting, Earth Tapes, Electrical Safety, Cable Glands, Arc Flash Protection & Fusegear.

• Distributors for: 3M, ABB, Alroc, Band-It, Catu, Cembre, Centriforce, CMP, Elastimold, Ellis Patents, Emtelle, Furse, Lucy Zodion, Nexans Euromold, Pfisterer, Polypipe, Prysmian, Roxtec.

LV – Low Voltage Cable Joints, Glands, Cleats, Lugs & Accessories (1000 Volts)

MV HV – Medium & High Voltage Cable Joints, Terminations & Connectors (11kV 33kV EHV)

Cable Laying – Underground Cable Covers, Ducting, Seals & Cable Pulling Equipment

More…

T&D’s Power Blog covers: LV MV HV & EHV Transmission & Distribution, Substations, Switchgear, Cable Jointing & Termination, Cable Fault & Repair, Underground Cables.

➡ Visit Power Blog