Breaking Down HV Cable Boxes & Using Guroflex - Applications & Tips

By Chris Dodds on 7th September, 2015

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Guroflex Cold Pour Insulating Compound, manufactured by Tyco (TE Connectivity), has virtually replaced hot pour bitumen type cable box compounds - Guroflex is easier and quicker to break down and clean out.

No heating is needed therefore no heat stress is inflicted on the high voltage bushings.

Guroflex compound insulates high voltage cable connections and improves the clearances of the 3 phases on all cable box terminations between 6.6kV and 33kV - the 2 part synthetic cable compound provides insulation in cable end boxes where traditional heatshrink or coldshrink type bushing boots cannot be used. 

Pictured : A High Voltage Cable Box Break Down Insulated With E38 - the E38 is scooped out by paint scraper and the cable box is cleaned down using cleaning rags and 3M cable cleaners, such as 3M CC4 wipes. 

Image : Andrew Brezovszky (EHV Cable Jointer).

Tip : Loosen the sides of the front cover on the cable box. Remove the filler hole cap at the top of the cable box and put infra red heaters on the outside for a few hours. Leave a drip box underneath with some oil sorbent pads. If you leave the front cover on loose the heater lamps cannot burn the cable box bushings. (By Andy O' Malley). 

TE Connectivity Guroflex has recently been banned by UKPN (December 2014 Doc : EBP 02-0058) for the purpose of topping and re-making of old cable boxes, containing PILC cables. UKPN permit the continued use of Guroflex where the cable box contains polymeric insulated cables (XLPE or EPR) - the cable must be fitted with a UKPN approved heatshrink cable termination.  

Following a spate of cable box failures and investigations UKPN determined that Guroflex is not compatible with PILC cable and bitumen compound. UKPN concluded "with immediate effect, Guroflex shall not be used to top up or refill cable end boxes that contain PILC cable and/or bitumen or G38 compound.

Pictured : Burning Down An 11kV Cable Box

The following Cable Jointing Manual issued by Central Networks, a UK DNO now part of Western Power Distribution, concisely covers the steps required by the cable jointer to burn out traditional compound cable boxes and re-terminate using 11kV triplex cables and Guroflex.

• Further reading

11kV Cable Box Terminations (Compound Filled) - Breaking Down & Terminating With Triplex Cables

Cable Fault Analysis : 5 Case Studies - Heat Shrink Cable Joints & Cable Terminations

 

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Established since 1985, T&D distribute the most extensive range of LV, MV & HV Cable Jointing, Terminating, Pulling & Installation Equipment - contact us today for a competitive quotation.

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Tyco Guroflex High Voltage Electrical Insulating Compound

Category:  Cable Jointing - PhotoBlog

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