BLL Overhead Line Covered Conductor

Product Description / Technical Information

BLL conductor uses a triple extruded polyethylene covering consisting of a semi conducting layer, a clear insulating layer and a coloured UV stable layer. It is designed with integrated longitudinal water tightness through the addition of a polyethylene filler between the strands during production which ensures that the covering does not slip during use and no grease is required during the production of this conductor.

Specification

BLL conductor can be produced as standard in sizes from 50mm to 241mm.

Standard specifications for CCST construction are as below

• Conductor – AAAC
• Extruded longitudinal water blocking layer
• Extruded, inner semiconductive layer
• Insulation of PE
• Outer layer of UV resistant HDPE

Note: Other specifications of conductor are also available

• CCSX – Insulation of XLPE, Outer layer of UV-resistant XLPE
• CCSX Hybrid – Insulation of XLPE, Outer layer of UV-resistant HDPE

 

Cross section	50	70	99	120	159	241	329	[mm²]
Lay up of conductor	7×3,08	7×3,57	7×4,25	19×2,84	19×3,26	19×4,02	37×3,37	[-]
Conductor diameter, bare conductor	9,24	10,71	12,75	14,2	16,3	20,1	23,59	[mm]
Inner semi conductive layer, thickness	0,3	0,3	0,3	0,3	0,3	0,3	0,3	[mm]
Inner PE covering, thickness,	1,2	1,2	1,2	1,2	1,2	1,2	1,2	[mm]
Outer UV-resist. HDPE-covering, thickness,	1,1	1,1	1,1	1,1	1,1	1,1	1,1	[mm]
Diameter over covering, min – max	13,9-15,3	15,4-16,8	17,4-18,8	18,8-20,3	20,9-22,4	24,7-26,2	28,1-29,7	[mm]
Weight,	247	313	417	506	635	920	1244	[kg/km]
Rated operating voltage	20(24)	20(24)	20(24)	20(24)	20(24)	20(24)	20(24)	[kV]
DC-resistance at 20°C, maximum	0,600	0,445	0,318	0,259	0,2000	0,1265	0,099	[ohm/km]
Resistance temp. coefficient	0,004	0,004	0,004	0,004	0,004	0,004	0,004	[/°C]
Lightening impulse withstand strength of HDPE layer	100	100	100	100	100	100	100	[kV]
Operating temperature, maximum	70	70	70	70	70	70	70	[°C]
Max load(IEC 61597), cond.temp 70 °C, air temp. 20°C, wind speed 0,5 m/s, approximate value	205	244	301	339	396	512	617	[A]
Max short circuit current, 1 sec. 50-200°C	5,1	6,8	9,6	11,7	15,5	23,4	32,0	[kA]
Tensile strength of conductor, minimum	14,3	18,6	25,3	34,9	43,6	61,5	90,8	[kN]
Aluminium alloy	AL7	AL7	AL7	AL7	AL7	AL7	AL7	[-]

Drum Dimensions

BLL conductor is available on multiple size drums depending on conductor size and lengths required for specific projects.

Standard drum lengths for common conductor sizes as below

BLL	Length	Dimensions of Drum
50mm	2000m	1.2m x 0.98m
62mm	1000m	1m x 0.71m
120mm	1000m	1.2m x 0.98m
241mm	1000m	1.6m x 1.2m

Installation

Ritelite’s experienced staff work with DNO’s to specify the right fitting’s solution for each project.

Ritelite has worked with many UK fitting suppliers to test BLL conductor with a number of fitting solutions including

• Compression fittings
• Preformed ties
• Arc protection solutions

Ritelite is also able to supply a range of tools for installation including

• Cumalong clamps
• Cable socks
• Stripping tools
• Cable rollers

Areas where BLL has been installed to date in the UK

• Bird strike areas – where the line is in bird flight paths
• Through wooded areas where there is likely to be disruption from trees
• Public access areas
• High wind areas and wind farms
• For Anti-copper theft applications
• Coastal salt water areas

Features and Benefits of using BLL

 

FEATURES OF BLL	BENEFITS
Non compacted construction	No problems with vibration
Inner & Outer cores bonded to give no slippage of outer covering	Conductor will break before any slippage occurs. Allows full tensions to be applied via covering.
Meets EN standard 50397	Compatible for use with all accessories and fittings made to standard.
Covered conductor	Prevention of harm to animals and humans who come into contact with conductor Prevention of short circuits when line effected by wind, trees falling on line, birds flying into line. Less attractive to line sabotagers
100% recyclable	Meets latest European policy requirements.
Conductor covering contains additives against voltage break down	Track resistant.

Ritelite offers DNO’s full assistance on all BLL projects from the planning of a line to delivery of materials. To find out more about BLL Covered Conductor or to get a quotation for your project please contact the sales office on 01780 765600 or email [email protected]

Ritelite offer training lines and facilities to assist with:
• Installation training for linesman, supervisors and contractors
• Support including presentations to linesman and planners at training facilities or depots

Support for Planners and Designers

From initial scheme design to completion of project. This would include:

• Arc Protection Requirements
• Accessories & Integration into Existing Network

Support for Project Delivery

• Delivery of all materials, tooling and conductor in a kit format
• Supply of specific drum lengths of conductor labelled with pole references
• Site visits if required pre installation
• Provisions of Trailers & Winches if needed

All training and product recommendations sanctioned by network engineers.

Testimonials

“Our first line of BLL was put up in Crowland West, Lincolnshire in 2005 to cure a problem of a regular swan flight path crossing bare conductors. This was just outside the local MPs residence (and he got quite upset each time a swan died). The conductor has done its job and there have been no further power disruptions to the village. Since then many other lines have been put up in Lincolnshire. There have been no faults and performance has been excellent. Our linesman found BLL easy to work with once familiar with the IPC construction and we continue to use it where and when applicable.” Kevin Wade – WPD Stamford, Lincolnshire