Jointers Blogs
Heat Shrink Cable Terminations – Potential Critical Medium Voltage Power Outage
April 25th, 2018-
uploaded by Chris Dodds - Thorne & Derrick Sales & Marketing Manager
Medium Voltage Terminations
A Cause For Concern
MV HV Application: Electric Arc Furnace Power 48 MVA 13.8kV
The heat shrink cable terminations are connecting the 13.8kV high voltage power cable to Siemens Circuit Breakers (3AH2 Type) with vacuum ruptors located in the MV-HV control room – notice the bleeding mastic melting from the cable terminations suggesting overheating potentially caused by sub-standard jointing at the semicon screen cut of the MV-HV cable. The client has used suitable electrical cable cleaners to remove the mastic however the situation is recurring and the client is extremely concerned about the potential risk of a critical power outage caused by eventual failure of the cable in the furnace vacuum circuit breaker.
Although no diagnostic results are available for this application the information is posted to highlight the potential shortcomings with respect to cable preparation prior to the installation of the cable terminations – medium voltage terminations and cable joints should only ever be installed by Trained & Competent Cable Jointers using the correct cable preparation tools.
“The bulge at the bottom of the cable termination will be the red mastic applied over the constant force spring. Definitely too much yellow mastic over the semi-conductive screen ends (large bulge), really no need to fit that much by the cable jointer. I witnessed some testing some years ago in the Elcon HV lab (see Elcon listed on the anti-track heat shrink tube) and the jointer applied less than half that was in the termination kit, just enough to fill the small semicon screen cut void. But the partial discharge (PD) reading was near zero. Apply too much and the PD readings were far above acceptable test standards but not enough to cause this heating issue. Would have liked to have seen some more pictures further out and different angles. But with the red mastic flowing and the discolouration of the heat shrink tubes, a lot of heat there and could be an earthing issue and high circulating currents present as a result.” Richard Poulter, Shrink Polymer Systems.
Medium Voltage Electrical Equipment
Siemens 3AH2/3AH4 Vacuum Circuit-Breakers
In the voltage range up to 24kV, up to 60,000 operating cycles are possible with Siemens 3AH2 circuit-breakers. Minimum maintenance work, such as greasing of operating mechanisms after 10,000 operating cycles and replacement of vacuum interrupters after 30,000 operating cycles, preserves the reliability of these circuit-breakers throughout their entire service life – despite high mechanical stress.
Siemens vacuum circuit-breaker type 3AH4 up to 33kV/36kV is designed for extremely high numbers of operating cycles – the circuit-breaker controls 120,000 operating cycles. 3AH4 circuit-breakers master this extreme stress throughout their entire service life.
Greasing of the operating mechanism is not required until 10,000 operating cycles have been reached – vacuum interrupters just have to be replaced after 30,000 operating cycles.
Note: Due to low quantities, the 3AH2 medium voltage vacuum circuit-breaker will be discontinued by December 31, 2007. As of January 1, 2008, Siemens will offer this circuit-breaker type for another 10 years for replacement purposes only.
➡ See also: T-Plug Cable Connectors – 33kV Medium Voltage Switchgear Connectors For Siemens NXPLUS C
MV Medium Voltage Jointing, Terminating & Electrical Equipment Specialists
Medium Voltage Product Categories
Thorne & Derrick are specialist distributors of Medium Voltage Cable Accessories, Copper Earthing Products and Electrical Equipment for use with 11kV/33kV underground cables and overhead lines – including an extensive range of heat shrink, cold shrink joints, terminations and connectors for LV MV HV cables.
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
3M | Nexans Euromold | Pfisterer | MV HV Joints Terminations Connectors
Nexans Screened Elbow Terminations (Type C Bushings On 33kV Transformer)
April 18th, 2018
More info: Euromold Screened Separable Connectors
- Application: Type C Bushings On 33kV Transformer
- Contributor: Dave Boyd EHV Cable Jointer – HV Cablepower Pty Ltd
- Featured Manufacturer: Nexans
- Product Type: Type C Bushing Connectors
Nexans Screened Elbow Terminations
Nexans Euromold 480TB type MV separable connectors are used to terminate MV-HV XLPE/EPR (polymeric) insulated cables up to 42kV into Interface C Bushings.
Nexan’s 480TB tee connector with 630A – 1250A current rating is designed for Interface C and covers voltages from 12kV to 42kV with a maximum conductor size of 300sqmm.
Nexans separable connectors are typically used to terminate cables on power systems and circuits distributing MV-HV electricity at 6.6kV, 11kV, 33kV and 66kV according to CENELEC EN50180 and IEEE ANSI – in the site photographs below the 33kV single core cables (185sqmm) with XLPE insulation and copper wire screens are shown prepared and awaiting connection of the Euromold connectors. The copper wire screens are oversleeved with green/yellow insulation and bonded to earth point.
Once installed the high voltage cable terminations were subjected to and passed VLF, Tan Delta and PD tests.
Euromold
The Euromold range of Separable Connectors are suitable for the termination of power cables onto all MV-HV bushing interfaces:
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View the complete range of Nexans Terminations | Joints | Connectors
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, Underground Cable Protection, Cable Jointing Tools, Feeder Pillars, Cable Ducting, Copper 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
Waveform Cable Termination – 3 Core 300sqmm Cable Onto A 2 Ganged Metered Way In Lucy Cabinet
April 11th, 2018
- Application: Waveform Cable Termination
- Photo by: James Hitchmough Operations Manager at Matrix Networks Limited
by Chris Dodds T&D - estimated reading time 3 minutes
Lucy LV Distribution Cabinet
Lucy Fused LV Distribution Cabinet
The Lucy Electric AcuLok TMO range of transformer mounted low voltage distribution cabinets incorporates the unique AcuLok fuse handle system – improving reliability and operator safety levels.
The LV cabinet is suitable for outdoor applications or indoor as part of a unit substation, the high equipment specification includes current transformers for load monitoring, a programmable digital meter, integral 660A Veam Powerlock generator sockets and an RCD protected auxiliary socket.
- Multi position attachment option for mechanical cable connectors on fuse stalks
- Individual load-bearing cable cleat per fuse way
- Easily removable fuse stalks for connector attachment
- Complete 3 phase fuse ways are easily removable to allow panel reconfiguration
- Live current measurement per fuse handle facility
- 4, 5 or 6 outgoing fuse ways
- 800A or 1600A busbar ratings
- MCCBs up to 1600A fitted to a chassis assembly
- ACBs up to 2500A directly connected to transformer flange
- 3-phase disconnector handle
- 4-core cable kit
Waveform Cable Accessories
T&D UK distribute an extensive range of low voltage utility waveform power cables including cable joints, cable cleats, cable glands and accessories required to lay and install waveform cables to BS7870.
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, 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.
11kV Heat Shrink Cable Terminations Connecting XLPE Wire Screened Cables
April 11th, 2018
- Application: 11kV Heat Shrink Cable Terminations Connecting XLPE Cables
- Cable Termination Type: Raychem Heat Shrink Termination
- Cable Type: XLPE Wire Screened Cables 11kV Single Core
- Cable Jointer: Stuart Duncan HV/LV Cable Jointer at CableTec Services
- Featured Manufacturer: Raychem
11kV Heat Shrink Cable Terminations
Single core 11kV heat shrink termination for medium or high voltage XLPE cables in indoor applications are designed to terminate polymeric insulated 11kV cables into air insulated switchgear and cable end boxes.
Single core 11kV cable termination kits are supplied with all the necessary components for 3 single core terminations:
- Stress-control tubing kit
- 3 x heatshrink cable termination tails (650mm per core)
- Earth kit for 11kV cables with copper tape screens
- Mastic tape
- Cable termination installation instructions
3 core termination kits are supplied with all the necessary components for 1 three core terminations:
- 3 core breakout sleeve
- Stress-control tubing kit
- 3 x heatshrink cable termination tails (650mm per core)
- Earth kit for 11kV cables with copper tape screens
- Mastic tape
- Cable termination installation instructions
➡ Cable Terminations | Cold Shrink 11kV Termination | Heat Shrink 11kV Termination
The cables have been terminated using heat shrink cable terminations and bolted to the copper busbar using crimp or mechanical shearbolt 11kV cable lugs. The 11kV copper wire screens have been bundled and bonded to an earth point using brass type mechanical lugs.
Note the smooth and even completed finish of the anti-track heat shrink (coloured red) to the cable termination evidencing the subtle skill of the cable jointer to avoid over-heating or localised scorching to the heat shrink tubes by inconsistent application of the naked flame from the heat shrink gas torch.
Should you require any assistance with the selection or specification of heat shrink terminations or cable joints for medium/high voltage electrical cables and power systems please do not hesitate to contact us.
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, 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.
Raychem Cable Terminations – HV High Voltage Outdoor Substation 88kV
April 11th, 2018
- Application: Terminating HV High Voltage Outdoor Substation 88kV
- Cable Type: Nexans
- Cable Termination Manufacturer: Raychem Cable Terminations
- Cable Jointer: Henry Kriek High Voltage Jointer at CBI Electric Power Installations
Cable Terminations
Raychem cable terminations using heat shrink technology can operate under severe environmental conditions for connecting and terminating MV HV cables in both indoor and outdoor applications.
Polymeric insulated cables of various designs and cross sections can be adopted with respect to shielding and metal sheath. Composite housings with different creepage lengths up to 50 mm/kV are available for the most common and also extreme pollution levels according to IEC 60071-1 and IEC 60071-2.
Brugg cable stripping tools were used by the cable jointer to strip tand prepare the single core high voltage 2500sqmm XLPE insulated cables.
High voltage products help enhance the safety, reliability and efficiency of power networks while minimising environmental impact in applications such as substations, power transmission, enabling smart grid and enhancing eco-efficiency.
Operating and maintaining high voltage systems requires experienced operatives with specialist skills.
CBI Electric African Cables
Since 1935, African Cables, now CBI-electric: African Cables designs and manufactures a comprehensive range of MV HV electric power cables at its Vereeniging factory.
CBI-electric: African Cables is the only cable manufacturer in Southern Africa to supply a range that meets any user requirement, irrespective of load. Included in this manufactured range are low voltage PVC/XLPE insulated cable; medium voltage XLPE; paper-insulated cable, aerial Bundled Conductor (ABC), ACSR and high voltage XLPE insulated cable.
Should you require any assistance with the selection or specification of MV HV cable joints or terminations please do not hesitate to contact us.
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, 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.
