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MV HV Power Cables & How To Remove Fabric Layers – Some Cable Jointers Tips

• by Chris Dodds T&D - estimated reading time 5 minutes

Preparation of MV-HV cables is critical to the electrical performance and reliability of medium/high voltage power cable circuits – failure to correctly strip, remove or cut cable construction layers using the appropriate Cable Jointing Tools can build-in future failure to the installed medium/high voltage cable joint, termination or connectors.

The following LinkedIn Comments provide expert guidance and advice on how to remove fabric layers from MV-HV cables without jeopardising or compromising cable functionality.

Medium & High Voltage Cable Jointing

Cable type pictured is 15kV Medium/High Voltage power cable

15kV MV Primary UD EPR Cable Specification

• Primary Underground Distribution Cable (Single Phase)
• Aluminium Conductor 750 MCM
• EPR (Ethylene Propylene Rubber) Insulation
• Easy Strippable Insulation Shield
• Application – Medium voltage primary underground distribution cable for conduit systems, direct burial, underground cable duct
• Manufacturer – CME Mexico (CME Wire and Cable, Inc. was established in the USA in 1994 as a subsidiary of Viakable to serve customers in the US and Canada).

How To Remove Fabric Layers From MV HV Power Cables

David Lundin (Contractor Compliance Specialist at Western Power) – remove the cable fabric layer by gloved hand and clean away residual material with carbon tetra chloride or equivalent cable cleaners.

Erik Liljedahl (Site Intallation Manager on NKT HV High Voltage Cables) – carefully remove the band with a knife, be careful not to damage the cable conductor strands, then brush the conductor with a wire brush. This fabric is to prevent the inner semi-conductor to fall between the conductor strands during cable production and allows the XLPE insulation to move during heat treatment – this fabric is usually a present layer on 100kV-600kV cables but also 11kV-33kV.

Peter Hembry (Director at Hembry High Voltage Services) – unravel to the primary insulation and pull it against the blade of a sharp knife all the way around, then give it a quick lick of heat to catch any strands you may have missed.

Ben Lanz (Director, Applications Engineering at IMCORP) – unless this is an unusual cable design, the inner semi-conductor (conductor shield) layer should come off cleanly. Any residue can be typically wiped off with a lint free cloth. After you wire brush the aluminium oxide off the conductor and immediately apply the oxide inhibitor, you will be ready to apply the connector (either compression or mechanical shearbolt). If you are not familiar with MV and HV cable in general, I recommend jointer/splicer training.

Mark Jones (Renewables Marketing Manager at Synergy Cables USA Ltd) – box cutter with a new blade works well. Cut slowly while keeping tension by rolling it under itself.

David Tompsett (Project Engineer at Northern Ireland Electricity) – seen this conductor screen removed by using twine instead of a knife. Good clean edge and no risk of damage to the outer conductor strands of the MV-HV cable.

Glyn Moore TMIET (Electrical Tech / Construction Manager) – as previous comments to remove the fabric either under or over wrapped once you are square with your insulation pull the fabric onto a sharp blade away from conductor, bit of a flame from a heat shrink torch to remove loose fibres. 

Darren Street (Cable Jointer at D+R Jointing Services Ltd) – sharp knife and a trained cable jointers touch (also blow it over with a gas torch to catch any wayward strands).

Ciaran McDowell (HV / LV Authorised Cable Jointer) – used it on high voltage tails in medium/high voltage transformers a few years ago. Use a sharp knife like a Stanley and pull the fabric under tension against the blade. This worked well just leaving a few threads to trim off. 

Eoin MacQuaile (Junior Quantity Surveyor at Obelisk) – use a piece of twine and wrap it around the cable material and use a saw-like motion to heat and cut the fabric without scoring the aluminium. This method evenly cuts insulation and wrapping without damaging conductors.

Kevin Kruse (Vice President, Engineering and Technical Support) – I have completed many cable termination demonstrations and we were always made fun of because we used string, but this is safest method. Second is some of the tools like Speed Systems or Ripley Jointing Tools where you can set a safe depth just shy of the conductor diameter. Cable jointers should never use a knife or box cutter.

Tim Poirier (HV Systems Manager- North America TE Connectivity) – best method is to tear it and then using a cable splicing knife at the cut back tearing it against the blade being careful not to nick the aluminium if any strands of the fabric remain burn off with a heat shrink torch.

Justin Kelly (Underground Network and Cable Splicer at JEA) – knife work, the cornerstone of legitimate medium voltage cable splicing and jointing. This is why splicing has historically been taught in 4-5 year apprenticeships, not 6 week classes. Skill takes time.

Stephen Davies (Technical Policy Engineer – Western Power Distribution) – this should be pulled against a static knife edge by the cable jointer so as to not damage the aluminium conductor. It is a semiconductor woven tape that prevents the semicon extruded layer bedding between the aluminium strands.

➡ String is simple but effective for clean cutting without damaging underlying cable conductors.

MV HV Power Cables

Primary Underground Distribution MV Medium Voltage Cables

• Primary UD MV Cable TR-XLPE / LLDPE, Concentric Neutral
• Primary UD MV Cable EPR / LLDPE, Concentric Neutral
• Primary UD MV Cable TR-XLPE / PVC, Concentric Neutral
• Primary UD MV Cable EPR / PVC, Concentric Neutral
• Primary UD MV Cable PILC Replacement, EPR/PE
• Primary UD MV Cable TR-XLPE Insulated, Concentric Neutral
• Primary UD MV Cable EPR Insulated, Concentric Neutral

High & Extra High Voltage Cables & Cable Systems

• High Voltage Copper Cable, Smooth Aluminum Shield/Sheath, XLPE Insulation, HDPE Jacket, 69kV – 138kV
• High Voltage Copper Cable, Wire and Tape Shield, XLPE Insulation, HDPE Jacket, 69kV – 138kV
• High Voltage Aluminum Cable, Smooth Aluminum Shield/Sheath, XLPE Insulation, HDPE Jacket, 69kV – 138kV
• High Voltage Aluminum Cable, Wire and Tape Shield, XLPE Insulation, HDPE Jacket, 69kV – 138kV
• Extra High Voltage Copper Cable, Smooth Aluminum Shield/Sheath, XLPE Insulation, HDPE Jacket, 230kV
• Extra High Voltage Aluminum Cable, Smooth Aluminum Shield/Sheath, XLPE Insulation, HDPE Jacket, 230kV

T&D are UK Main Stockist for Alroc Tools suitable for all types of LV MV HV cable preparation prior to installing cable joints, terminations and separable connectors.

International standards and local practices vary considerably, here a Indian cable jointing team are shown using knives and hacksaws to remove cable sheath jacket and primary insulation from Prysmian 220kV to 550kV EHV cables. Image: Audhesh Giri (EHV Cable Jointer/Cable Supervisor)

Here a smooth finish to the XLPE insulation on a high voltage power cable has been achieved with use of a Makita sanding machine

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, copper earth tapes and substation earthing at LV, 11kV, 33kV and EHV.

Based in the UK, are the Specialist Distributor for the Nexans Power Cable Accessory range of Screened Separable Connectors (Euromold), Cold-Applied (AIN AFN) & Heat Shrink Joints (JTS) & Cable Terminations (MONO) for Medium Voltage Power Systems up to 66kV; we hold extensive stocks and provide the most competitive commercial and technical levels of customer service in the UK.

Armed Forces Covenant

Thorne & Derrck are committed to honour the Armed Forces Covenant and support the Armed Forces Community – a signed copy is available below as a download.

We recognise the value Serving Personnel, both Regular and Reservists, Veterans and military families contribute to our business and our country.

The Armed Forces Covenant is a promise from the nation that those who serve or have served, and their families, are treated fairly.

Armed Forces Covenant – Thorne & Derrick International

Apprentice Internal Sales Engineer – Business Admin | Customer Service Level 2

Thorne & Derrick is a family owned company, established in 1985. It is a leading specialist distributor of Power and Process Engineering Equipment in the UK and Internationally.

Due to continued growth we have an opportunity for an Apprentice Internal Sales Engineer based at our Chester-le-Street office.

The role is within a fast paced sales environment where you and your colleagues have the responsibility for driving business to business sales in the following sectors: Oil and Gas, Petrochem, Water, Power, Building Services, Rail, Renewable Energy, Hazardous Area Industries.

You will be trained to handle the following key responsibilities:

• Taking inbound calls from customers
• Negotiating to win business and cross selling associated products
• Calculate accurate and competitive sales quotations based on technical information issued by clients
• Follow up quotations in a timely manner
• Making outbound sales calls to pre-identified target accounts
• Liaising with Sale Reps, Customers, Depots and Suppliers
• Processing orders from customers
• Dealing with queries relating to orders
• Creating sales reports
• Updating orders, prices and order confirmations in the Company’s systems
• Updating the Customer Relationship Management software.
• Occasional customer visits

Background, Skills & Qualifications

• Previous work experience gained in a customer services or sales role an advantage
• You must have a desire to build a career in industrial sales and account management
• Strong written and oral communication skills are essential
• Excellent attention to detail is essential
• Strong IT skills that include Microsoft Office (Word, Excel, Email & Web) awareness and experience is essential
• GCSE’s in Maths and English and two A Levels or equivalent
• A clean driving licence and own car would be useful but is not essential

Training period 12 – 18 months including fortnightly college attendance.

25 days holiday

8.30am to 5.00pm – 5 days per week

This is a career opportunity as the position will be made permanent on successful completion of the apprenticeship.

Starting salary £15,500 – Salary will be reviewed after successful completion of the apprenticeship period.

Apply

The apprenticeship will be run through the Northern Skills Group. Please see their website for more information on the Business Admin and Customer Service Level 2 courses.

Northern Skills Group is an expert provider of apprenticeships, employer-led training and retraining and works with over 2000 businesses in the North East and Yorkshire. We provide expert tuition, funding guidance and assistance with apprentice recruitment.

Experts in Apprenticeships and Training from Northern Skills Group on Vimeo.

➡ Please email Mr Richard Derrick [email protected] with your CV and a covering letter explaining more about yourself.

Please visit our website for more information on our business, www.thorneandderrick.com

Thorne & Derrick International

Thorne & Derrick International are specialist distributors of LV, MV & HV Cable Installation, Jointing, Duct Sealing, Substation & Electrical Equipment – servicing UK and global businesses involved in cable installations, cable jointing, substation, overhead line and electrical construction at LV, 11kV, 33kV and EHV.

THORNE & DERRICK 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 

Prysmian Multicleats – 3 Simple Steps To Cable Cleat Installation

Prysmian BICON Multicleats – Cable Cleats

• by Chris Dodds T&D - estimated reading time 5 minutes  

Cleats

T&D are Prysmian cable cleats stockists and distributors committed to supporting the correct installation of all BICON brand products – the following short post outlines the recommended installation procedure for Prysmian Multicleats which are specified to provide short-circuit containment of LV, MV and HV power cables.

Prysmian Multistrap is a stainless steel cable strap complete with a tensioning clip, securing pin and winding key – can be used for single, bundled or trefoil cleats including 11kV/33kV single core high voltage substation cables.

BICON. A Prysmian brand.

Multistraps are used as an intermediate cable restraint between Multicleats – positioned centrally between a pair of Multicleats to provide additional protection to medium/high voltage power cables in the event of a short-circuit.

The Multicleat cable cleats are commonly used to support and clamp 11kV/33kV power cables in industrial installations, hazardous areas and high voltage substations.

Aluminium cable cleats are also available for cleating cables onto containment in LV-HV substations and electrical building services where corrosion exposure levels are lower.

Multicleats

1. Fasten Prysmian BICON Multicleat base to cable support with M10 fixings. Loop Prysmian Multistrap through cable cleat base and around cables. Standard Duty Multicleats = 2 loops. Heavy Duty Multicleats = 3 loops.

2. Pull slack Prysmian Multistrap into outer loop. Insert split pin from right hand of Multicleat around outer layer of Multistrap about 10mm from end. Push plastic shear torque adaptor fully onto the end of the split pin and attach 13mm socket wrench. To tension the Prysmian Multistrap around the cables, rotating key anti-clockwise with the socket wrench until the adaptor shears.

3. Remove the shear torque adaptor and wrench. Swing the key over and engage in slots in clip.

The Prysmian Multicleat and Multistrap is correctly installed – compatible with most cable containment types including cable ladder and tray systems.

Prysmian BICON Multicleat Installation Steps

For further Multicleat & Multistrap technical specification, selection details and information see the following Slideshare.

To ensure sufficient cable support the Prysmian Multistrap MUST be used at the mid-point between Multicleats on all horizontal or vertical straight cable runs – here the Multicleats are shown cleating single core 33kV cables in trefoil arrangement however the strap-type cable cleats are suitable for single, multiple or bundled cable configurations.

Contact Thorne & Derrick for technical support or specification advice to ensure the correct cable cleat / cable strap arrangement according to the fault rating, installation application and environmental location.

Also from Prysmian  ➡ Cable Joints | Cable Glands | Cable Cleats | MV HV Terminations Joints Connectors 11kV 33kV

THORNE & DERRICK SPECIALIST ELECTRICAL DISTRIBUTOR

LV ♦ MV ♦ HV

T&D distribute the most extensive range of LV, MV & HV Cable Jointing, Terminating, Pulling & Installation 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, Underground Cable Protection, Copper Earth Tapes, Cable Jointing Tools, Feeder Pillars, Cable Ducting, Earthing & Lightning Protection, 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

T&D, CATU Electrical Safety & Arc Flash Protection Specialists for SAP’s, Linesmen, Jointers & Electrical Engineers – Largest UK Stockist

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.

Balata Polyester Cable Straps – Balfour Beatty Rail – T&D UK

Balata Cable Straps To Support Rail Cables (LU & Network Rail Approved)

Project Application : Tunnel Cable Support for Power Cables

Product : Balata Straps

Scope : Supply off 10,000 LU-NYBAL-1 Balata polyester cable straps for the new DC Traction Sub Station & Tunnel Cables in West Ham, London UK.

Client : Balfour Beatty Rail

Country : UK

Sector : Rail

Balata Polyester cable straps are designed as a secure and reliable cable supporting method which is LU London Underground and Network Rail approved – the cable straps are specified to provide surface and sub-surface cable support in overground and underground locations on the UK rail infrastructure; this includes trackside substations, underground tunnels and bridge crossings. The inherently flame retardant cable straps, specified by London Underground (TfL) since 1965, provide superior aging and stable electrical characteristics suitable for installation in damp and dusty locations at both trackside and tunnel locations.

LV MV HV Jointing, Earthing, Substation & Electrical Eqpt

Rail Cable Accessories, Electrification & Installation Equipment

Thorne & Derrick stock and distribute an extensive range of 400V-33kV Rail Cable Accessories & Power Distribution Sytems including feeder pillars to contractors undertaking Low Voltage Power Distribution, HV Electrification & Substations, DC Traction & Networks, OLE and Track Feeder Cable Renewals – complete range of Network Rail PADS approved track terminations, cable joints, cable repair and connection products up to 25kV, including 3M Cold Shrink, Pfisterer CONNEX and Nexans Euromold products.

Full range of Cable Pulling Equipment & Products to ensure safe and efficient of rail cables in to cable ducts and containment infrastructure including cable troughs.

Cable Cleats | Cable Hangers | Cable Joints | Cable Glands | Cable Lugs | Cable Transits | Arc Flash Clothing