Question:

In what situation and applications should I use a Hazardous Area cable joint over a standard resin-filled joint?

Answer:

A Hazardous Area joint kit should be used if you have a requirement for your cable jointing solution, to be flame retardant, halogen-free or hydrocarbon resistant.

All of our 3M Hazardous Area joints have been tested extensively to prove their performance within hazardous and harsh environments and the effects of hydrocarbons and chemical solvents on resins and joint bodies.

The LVI-3 range of cable joints have been successfully installed within ATEX rated Hazardous Area including mines and quarries, underground applications, petrochemical sites and offshore areas where there is a risk of flame or explosion.

The specialist joint shell, which is flame retardant, hydrocarbon resistant and halogen free, is filled with a specially designed polyurethane resin, which is a highly modified joint resin mix, which makes the resin flame retardant, halogen free and virtually unaffected by immersion in either hydrocarbon or chemical solvent solutions.

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Question:

Are bushing extenders available for the Nexans Euromold Interface ‘C’ bushings? I have noted extenders are available for Interface D and E bushings but cannot find any examples for the interface C range.

Answer:

Unfortunately 400series bushing extenders do not exist. Being a European-designed product, it as always felt that sufficient control could be exerted over equipment manufacturers to negate the need for such a product. Unfortunately that hasn’t always worked and Nexans Euromold were forced some years ago to come up with a solution which is:

– Use a 400series tee connector, i.e. (K)400TB, for which Euromold produce an insulated rod/contact assembly to take the place of the cable which would normally be present.
– The bushing is then “extended” by using a conventional (K)400CP connecting plus and thread assembly.

Although it doesn’t look conventional, it is however the only solution and usually available within a few weeks, from ETS Cable Components.

Please note that this solution is only valid up to 24kV maximum.

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Question:

I’m about to use a bonded screen removal tool for the first time, how do I make sure it works correctly and the screen is properly removed from the cable?

Answer:
When terminating or jointing MV cables with a bonded semi-conductive screen, this will have to be shaved from the cable primary insulation to the dimensions given within the accessory installation instructions. There are a variety of tools available that will perform this task, however when using a purpose-made screen removal tool the following points should be noted to ensure the cable is prepared correctly:

Ensure the blade is set to the correct depth. Excessive removal of the cable insulation could increase the electrical stress at the point of removal, particularly with air-clearance terminations (Heatshrink and ColdShrink types). The best way to ensure the correct depth is to practice on a piece of unused cable first.

Some tools require the application of silicone grease to the semi-conductive screen in order to lubricate and ease tool rotation. Fully familiarise yourself with the usage instructions supplied with the tool you are using and practice on a few lengths of unused cable to “get the feel” of the tool.

Ensure the core is perfectly straight. Any bend in the cable can lead to the screen not being removed evenly around the circumference. This could happen to the underside of the cable and may not be immediately noticed, potentially causing partial-discharge issues.

Using a specialist tool usually results in a perfectly prepared core, but if small amounts of bonded semi-conductive screen are left on the cable these can be removed with the use of a fine abrasive, non-linting cloth (120grit minimum). Care should be taken to only abraid cables circumferentially (NOT longitudinally) to avoid creating a partial-discharge path along the cable insulation.

Once you have prepared your core(s), the primary insulation will require cleaning to ensure any loose particles are removed. Always clean polymeric insulation from the exposed conductor end, along and TOWARDS the semi-conductive layer in one direction, avoiding inadvertently contaminating the insulation with any semi-conductive compound residue.

There are a number of different types of bonded screen used on cables. Although the aforementioned procedures are common to most polymeric semi-conductive compounds, it is important to confirm that your tool and cable/s are compatible before commencing work.

ETS Cable Components offer a variety of quality-manufactured cable preparation tools from GBZ-Mannheim and Nexans. Please contact our Sales Team for further information, prices and advice.

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Question:

I need to secure a cable in triplex formation with the use of a trefoil cleat, how would I go about doing this?

Answer:

Triplex cables are formed by having their three cores twisted around each other, this causes an issue when trying to secure the cable with traditional trefoil cleats. As the relative position of the cable varies along the cable run, the three cores will be in a different ‘twisted’ position at each cleat interval.

The overcome this problem, a SFT triplex cable former is available. The inner liner is applied around the cable, giving it a uniform profile allowing it to be fixed within a two-bolt LSF, VRT Vulcan or single way ES Emperor cable cleat.

The triplex liner is manufactured from LSF Zero Halogen (LSZH) materials and thus is suitable for applications where LSZH properties are required.

2LSF Cleat with Triplex Liner	Vulcan Cleat with Triplex Liner	Emperor Cleat with Triplex Liner

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