• Application: 33kV Cable Terminations –  XLPE Cables Into VSLP9 Type Switchgear
• Cable Jointer: Craig Kilkenny – EHV Cable Jointer / Fitter
• Product Category: MV HV Power Cable Terminations

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

33kV Cable Terminations Installation

Here, high voltage substation cables are shown connected and terminated into switchgear using 33kV cable terminations.

The copper earthing tapes are used to bond all of the cable glands together which are providing mechanical retention to the 33kV high voltage power cables.

The earth tapes are clamped and attached to the substation earthing system as they are insulated from the 33kV cable box and high voltage oil-filled switchgear. The whole bank of HV switchgear is insulated from the ground and has its own earth which runs through a Current Transformer (CT) for protection reasons – the separate ‘frame earth’ is painted green in the photograph below. The stand for the cable cleats was also bonded to the substation earth. As there is a steel sandwich plate fitted to the front of the wooden cable cleats the threaded bar used is stainless steel to avoid circulating currents.

Sealing Cable Ducts 33kV

Client specified expanding foam has been used to seal the substation cable ducts within the high voltage substation – outside the substation the 33kV cable ducts were effectively sealed using a specified system to provide certain protection against water ingress and gas migration using recognised systems such as the CSD RISE duct seal or Filoform Filoseal re-enterable cable seals.

The insulating oil is usually heated before the high voltage cable box is dismantled by venting it above and heating with halogen heaters.

Stripping & Terminating 33kV Cables

The 33kV cables were stripped using the correct cable jointing tools – the PVC cable sheath was thoroughly stripped from the high voltage power cable using the Boddingtons “plough” type sheath stripper. The cable jointer then removed the XLPE insulation cleanly and without damaging the cable using Alroc LH2 tool suitable for cable stripping HV cables up to 60mm.

Finally, Alroc CWB 18-60 tool was used to remove the bonded semicon from the cable – the “blue tool” manufactured by Alroc is preferred by jointers for working on medium/high voltage power cables where a clean square cut of the semicon without jagged finish is vital to the long term reliability of power cable performance.

Poor cable jointing skills with respect to MV-HV cable preparation can create future cable failure potential – it is critical a skilled jointer uses the correct cable tools to prepare MV-HV cables before installing joints, terminations or connectors up to 33kV.

Comments from fellow HV cable jointers:

Jimmy Nicklin: “Nice job Craig Kilkenny. I did a nine bank of these 15 years ago and is quite the breakdown and remake to do.”

Dean Wilson: “Nice neat work Craig Kilkenny and yes I agree Jimmy Nicklin it’s getting the old oil out that’s a job in itself!”

Andrew Brezovszky:  “Very neat 33kV cable terminations !”

Thorne & Derrick International

Should you require any assistance with the selection or specification of heat shrink terminations to suit 33kV high voltage power cables please do not hesitate to contatct us.

T&D distribute the most extensive range of MV & HV Cable Joints & Terminations, Cable Installation Accessories & Cable Pulling Equipment – we service UK and international clients working on underground cables, overhead lines, substation earthing 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, Cable Spikers, 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.

A series of How-To videos for repairing, jointing and terminating cables using 3M Cold Shrink & Scotchcast products.

Cold Shrink

This video by 3M Electrical shows the benefits of using 3M Cold Shrink compared to heat shrink cable accessories to insulate, joint, repair and terminate cables.

3M cold shrink tubes utilise a unique cold applied delivery system which is designed to make cable jointing, insulating, termination and abandonment as simple as possible without any of the inherent workplace risks associated with “hot-working” and using naked flames to activate heat shrink type cable accessories.

Cold shrink reduces the risk of damaging XLPE cable insulation caused by scorching or over-heating of the cable by the jointer. No cooling time is required before energising cables.

Cold Shrink Benefits

Installation is fast and an easy one-step installation process:

• Labour Savings – enables installation of cable accessory in 1/3 of the time or less compared to heat shrink equivalents
• Tooling – no special heating tools or “hot-work” work permits required
• Compact – smooth profile cold shrink limits volume displacement on cable tray where congregated cable joints are located
• Outdoor – resistant to weathering for continued outdoor service in environmental and exposed locations
• User Friendly – easy to learn and train with less installation steps
• More Cold Shrink Videos | Cable Abandonment | Cable Terminations MV HV

➡ See How To Use Cold Shrink Tubes.  

3M Tubes – available in EPDM Rubber or Silicone

Depending on the application cold shrink is available manufactured in EPDM Rubber or Silicone – contact us to discuss your application.

Cold Shrink creates a static and stable cable seal that does not expand or contract with the cable under thermal cycling of LV-HV cables, potentially leading to the creation of voids between the cable accessory and the cable which could lead to a joint or termination failure.

Cold Shrink – invented by 3M over 40 years ago and now the preferred technology for heat-free jointing, terminating, sealing and abandonment of LV HV cables

We hope you find this video informative and educational, contact T&D for technical support, quotations and stock availability for 3M Cold Shrink.

Trust Cold Shrink

• Low Cable Failure Rates*:
  – 0.067% for Cold Shrink Cable Joints & Cable Splices
  – 0.022% for Cold Shrink Terminations

* Data based upon U.S. failure data of U.S. manufactured 3M Cold Shrink Medium Voltage Cable Accessories between 2009 and 2012.

3M

Should you require support about selecting the correct 3M Cold Shrink product range for use with low, medium or high voltage cables please contact us – a complete range of Cold Shrink cable joints and terminations is available for MV-HV cables, including 11kV/33kV.

➡ Visit 3M Electrical for further information about 3M cable joints, terminations, tapes and insulation to seal, repair, splice and connect LV MV HV cables.

Cold Shrink | Joint | Terminate | Seal | Repair | Splice | LV MV HV Cables | 3M

• 3M Electrical Products Stocked By Thorne & Derrick International 

Schneider Gas Insulated (SF6) Switchgear, RMU’s & MV Medium Voltage Electrical Equipment

• Uploaded by Chris Dodds – reading time 8 minutes

Switchgear Bushings & Cable Connectors

The following information has been provided to enable to correct selection and specification of MV Bushings and Separable Connectors used to connect and terminate medium/high voltage power cables into Schneider RM6 gas insulated switchgear and Ring Main Units (RMU) up to 24kV.

General

• The profiles, contacts and dimensions of the Schneider RM6 connection interfaces are defined by the IEC 60137 standard
• 100% of the epoxy resin interfaces undergo dielectric testing at power frequency and partial discharge tests
• Insulated connectors must be used in order to guarantee the dielectric performance

Appropriateness For Use

Types of Connection Interface

The bushings carry the electrical current from the outside to the inside of the MV switchgear enclosure, which is filled with SF6 gas, ensuring insulation between the live conductors and the frame for MV power distribution.

There are 3 types of MV bushing, which are defined by their short-time withstand current:

• Type A Interface Bushing: 200 A: 12.5 kA 1 s and 31.5 kA peak (plug-in)
• Type B Interface Bushing: 400 A: 16 kA 1 s and 40 kA peak (plug-in)
• Type C Interface Bushing: 630 A: 25 kA 1 s, 21 kA 3 s + 62.5 kA peak (disconnectable M16)

➡ For further information on Euromold Connectors for all other Interface Bushings up to 66kV please see the following information:

The Euromold brand of MV Cable Connectors manufactured by Nexans for 11kV 33kV 66kV connection of medium/high voltage power cables into gas insulated electrical equipment.

How To Define The Cable Connectors Interface

The connection interfaces depend on specific criteria, such as:

Installation

• Current rating of the connected equipment: 200, 400, 630 A
• Short-time withstand current for 12.5 kA, 16 kA, 25 kA switch and circuit breaker functions
• For the fuse-switch combination function, as the short-circuit current is limited by the fuse, the connection interface will be of type A (200 A)
• Minimum phase expansion length
• Connection type: plug in: multicontact ring, disconnectable: bolted
• Output position: straight or elbow connectors

MV Medium Voltage Cable

• Specified voltage: of the cable, of the network
• Type of conductor: aluminium or copper
• Cross section in mm²
• Primary insulation diameter
• Cable composition: single-core or 3-core
• Insulation type: dry, paper impregnated (non-draining type)
• Type of screen: copper tape or copper wire screen
• Armour: SWA (steel wire armour), AWA (aluminium wire armour) or unarmoured (copper wire screened)

Gas Insulated Switchgear – Schneider RM6

1. Stainless steel tank filled with SF6 gas, sealed for life and containing the medium voltage (MV) busbar and all live switching components such as the switch-disconnector, earthing switch, the fuse switch combination or the MV circuit breaker
2. One of the five cable compartments with interfaces to connect to the network or medium voltage transformer
3. User interface with single line diagram, actuators and LV components
4. Manual or motorised operating mechanism compartments
5. Earthing circuit with visible earthing contacts

Type A Bushing – Directed field plug-in connector

Dry single-core cable

➡ Further information link: Elastimold Connectors

Type A/M8 bushing – Non-directed field disconnectable connector (*)

Dry single and 3-core cable

(*) 520 mm plinth must be used

Type B bushing Directed field plug-in connector

Dry single-core cable

Type C bushing – Directed field disconnectable connector

Dry single-core cable

Non-directed field disconnectable connector

Dry single and three-core cable

Non-directed field disconnectable connector

Single-core cable, paper impregnated, non-draining type

Non-directed field disconnectable connector

Three-core cable, paper impregnated, non-draining type

Disconnectable Connector Single-core Dry Cable &

MV Medium Voltage Lightning Arrestor

See How Thorne & Derrick & Nexans Euromold can support your MV Bushings & Connectors requirements

Thorne & Derrick International

Since 1985 Thorne & Derrick based in the UK have been specialist distributors of LV, MV & HV Cable Installation, Jointing, Substation, Arc Flash Clothing & Electrical Safety Equipment – customers include UK and worldwide contractors, specifiers, traders and end-users involved in medium and high voltage cable installations, cable jointing, substation, overhead line and electrical construction.

We are specialist stockists and distributors of 11kV-33kV Cable Joints, Terminations & Connectors from manufacturers including 3M, Pfisterer, Prysmian and Nexans Euromold in a selection of cable jointing technologies including push-on, heat shrink and cold shrink joints and cold shrink terminations.

MV HV | Medium & High Voltage Power Products, Tools, Cables & Electrical Equipment

• Application: 15kV EPR Okonite Medium Voltage Cable – Primary UD Cables
• Cable Joint Type: Prysmian Cable Joints – Medium & High Voltage
• Cable Jointer: Christopher Fusarelli Splicer at The United Illuminating Company

Joints, Splices & Terminations to suit Okonite Cables LV MV HV | 15kV

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

MV Joints & Cable Preparation

1. MV Cable Preparation. The medium voltage cables are expertly prepared by the cable jointer/splicer using basic tools such as cable jointing knife, needle nose pliers and a scale ruler – no specialist cable jointing tools were used to complete this MV cable preparation or joint. To achieve this level of precision and accuracy without damaging the cable and jeopardising the medium voltage cable joint requires an exceptional skill level. The 15kV cable manufactured by Okonite is 750 KCMIL with EPR insulation and ready to be connected using Prysmian cable joints. The white tape overlap section between the copper tape screen and semicon screen is used to secure the medium voltage cable shielding in place.

2. Medium Voltage Cable Joints – Fire Proof. The medium voltage cable joint is over-wrapped to provide fire protection and arc proofing. This MV cable joint was for a new medium voltage circuit with several cable chambers so the 15kV cable is actually open on both ends and not grounded – “the phasing is not completed until every medium voltage cable joint or splice is completed except the first and last, and that’s when we phase it,” comments Christopher.

3. Medium Voltage Straight Joints – no tee (or branch) cable joints were installed, “this particular MV circuit isn’t very long and goes from substation to a dozen or so manholes, then the medium voltage cable terminates at a riser. If our circuit has wyes or tees, we still typically phase at the end,” added Christopher. Branch joints can be used to split main feeder cables into two cables that can be directed to other loads. 

Cable Pulling – the cable gang pulling 15kV 500MCM medium voltage EPR cable. Here the contractor is preparing to piece out a circuit that runs through the middle of the manhole (cable splicing or jointing chamber).

Prysmian Elaspeed Cable Joints

Prysmian Elaspeed cold shrink cable joints and splices are medium voltage cable accessories extensively specified in North American markets – Elaspeed are not molded cable joints. Elaspeed cable joints feature a core constructed from ethylene propylene rubber (EPR) on a vertical triple extruder which maintains concentricity on medium voltage cables. Cable joints are installed cold-applied without the requirement for heat or open flames associated with heat shrink cable joints.

Watertight Cable Joints

The circumferential pressure of the Prysmian Elaspeed cable jacket in conjunction with the cold flow properties of the mastic supplied with the cable joint kit will prevent water ingress. The Elaspeed MV cable joint has successfully passed external water pressure tests of 45 psi. In addition, the tight interface between the cable and cable joint body can withstand pressures up to 30 psi.

Compact Joints

Prysmian Elaspeed joints mimic the behaviour and performance of MV EPR cables in terms of bending radius in tight manhole situations – cable joints or splices can be bent to the same radius as the cable without impacting upon the performance of the joint. The small and smooth profile of the completed joint occupies less installation space where confined space working does not permit oversized joints.

Medium Voltages

Prysmian Elaspeed joints are available in the following voltage categories: 15kV, 25kV, 28kV, 35kV – the cable joints are available to also connect 3 core conductor armoured cables and aluminium inter-locked armoured MV-105 cables, including TECK Cable. Transition joints are also available to splice 3 or single core conductor paper lead (PILC) cables to 3 or single core conductor EPR / polymeric cables.

Prysmian | Cable Joints | Terminations | Cable Cleats | Connectors Distributor

Thorne & Derrick International

Should you require any assistance with the selection or specification of Prysmian cable joints please do not hesitate to contact us.

T&D distribute the most extensive range of MV & HV Cable Joints & Terminations, Cable Installation Accessories & Cable Pulling Equipment – we service UK and international clients working on underground cables, overhead lines, substation earthing 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, 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

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.

Uploaded By: Chris Dodds - reading time 5 minutes

Cable Covers

Centriforce Tapetile and Stokbord underground cable protection tiles and covers are the market leading, heavy duty utility protection system for protecting underground cable and pipes – this includes low voltage, medium voltage and high voltage power networks working at 11kV/33kV up to and including 132kV/275kV extra high voltage cables.

T&D supply the most extensive range of Centriforce Cable Protection products from stock for delivery throughout the UK to most UK DNO specifications in both Tapetile and Stokbord ranges – used to protect MV-HV Underground Cables & Joints.

Tapetile

& Stokbord Covers

Stokbord Cable Covers – 33kV Cable Protection For Underground MV-HV Cables

Tapetile – 11kV Cable Protection For Underground MV-HV Cables

See the complete Centriforce range: MV HV Medium & Voltage Cable Protection Products

➡ The following Selection Table outlines the current approved Cable Protection Systems for UK DNO’s for underground medium and high voltage cables.

Northern Powergrid	Centriforce	Tapetile	150×2.5mmx40m
Northern Powergrid	Centriforce	Tapetile	200×2.5mmx40m
Northern Powergrid	Centriforce	Stokbord	1000x244x12mm
Scottish Power	Centriforce	Tapetile	200×2.5mmx40m
Scottish Power	Centriforce	Stokbord	1000x244x12mm
UK Power Networks	Centriforce	Tapetile	200×2.5mmx40m
UK Power Networks	Centriforce	Stokbord	1000x244x9mm
Western Power Distribution (WPD)	Centriforce	Stokbord	1000x450x12mm
Western Power Distribution (WPD)	Centriforce	Stokbord	1000x244x12mm
Scottish & Southern Energy (SSE)	Centriforce	Stokbord	1000x244x12mm
GTC	Centriforce	Tapetile	150×2.5mmx40m
GTC	Centriforce	Tapetile	200×2.5mmx40m
National Grid	Centriforce	Tapetile	200×2.5mmx40m
National Grid	Centriforce	Stokbord	1000x300x14mm
National Grid	Centriforce	Stokbord	1000x450x14mm

Centriforce Benefits

Centriforce Stokbord and Tapetile heavy duty plastic underground cable covers have virtually replaced concrete cable covers, tiles and plates for several reasons:

• Clearest warning of underground buried cables to third parties
• Can be custom made with sizes to suit specific utility cable protection for 11kV, 33kV, 66kV and 132kV
• Contains bold warning text and UK DNO logo for clear cable identification
• Damage to medium and high voltage cables less likely therefore reducing the cost of repairs, jointing and outages
• Lightweight and easy to install cable covers irrespective of weather and soil conditions
• Durable with good impact resistance
• Rotproof and resistant cable covers to wide range of soil conditions

Electrical Explosion – An 11kV Cable Strike

Two construction companies have been fined £90,000 after workers were seriously burned, and one scarred for life, after they cut into a live 11kV electrical cable. Unprotected underground cables distributing medium and high voltage electricity pose serious health and safety dangers.

UK DNO’s

T&D are Specialist Distributors to the UK Distribution Network Operators (DNO’s), NERS Registered Service Providers, ICP’s and High Voltage Jointing Contractors of an extensive range of Cable Joints, Substation, Distribution, Tooling & Installation Equipment approved by the utilities:

• Electricity North West – ENW
• ESB Networks
• NIE – Northern Ireland Electricity Networks
• SPEN – Scottish Power Energy Networks
• SSE – Scottish & Southern Energy Networks
• UKPN – UK Power Networks
• WPD – Western Power Distribution 
• NPG – Northern Power Grid

THORNE & DERRICK SPECIALIST ELECTRICAL DISTRIBUTOR

LV ♦ MV ♦ HV

T&D distribute the most extensive range of LV, MV & HV Cable Jointing, Terminating, Cable 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, Underground Cable Protection, Cable Jointing Tools, Feeder Pillars, Cable Ducting, Earthing & Lightning Protection, Electrical Safety, Cable Transits, 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

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.