24kV Three-Core Heat Shrink Straight-Through Joint

The cable schedule says 12/20kV, three cores and 240 mm². Both cable ends are already at the jointing location. Is there enough prepared cable length and working space to complete the three connections, install the heat shrink components and close the joint assembly correctly?

That question should be addressed before installation begins, not after the cable sheaths have been removed.

RIKI’s 24kV three-core heat shrink straight-through joint range is intended for XLPE-insulated power cables. Four conductor-size selections cover 25–50, 70–120, 150–240 and 300–500 mm². The illustrated kit contains two long black tubes, three smaller red-ended sleeve assemblies and other accessories associated with the jointing process.

The Space Occupied by Three Connections

Each conductor in a three-core cable must be connected to its corresponding conductor on the opposite cable end. The prepared cores, connectors and surrounding insulation components all occupy space within the finished joint.

The jointing instructions determine the required conductor preparation lengths and relative connection positions. Depending on the approved kit design, connections may need particular axial positioning or separation to accommodate the insulation and protection components. An installer should not choose aligned or staggered connection positions simply from the product photograph.

The completed joint may occupy considerably more space than the original cable diameter. Where the installation is inside a restricted chamber, cable route or enclosure, the available longitudinal space and permitted cable bending must be checked against the actual joint assembly dimensions.

Two Cable Ends Mean Two Sets of Measurements

On a new installation, both cable lengths may have been supplied to the same specification. During a repair, however, the original cable and its replacement may differ in insulation diameter, metallic screening or outer sheath construction.

The catalog conductor range does not establish that two cables with different constructions can automatically be joined using the same standard kit. A compatibility review should use the specifications of both cable ends, including:

• Conductor material and nominal cross-section.
• Outside diameter over the prepared XLPE insulation.
• Metallic screen type, construction and bonding requirements.
• Armour type and outer sheath dimensions, where applicable.
• Connector dimensions and the intended connection method.

This is particularly important when the joint replaces a damaged section of an existing feeder. The new cable may carry the same nominal voltage and conductor area without having identical dimensions.

Heating Access Is an Installation Constraint

The heat shrink components must be positioned and recovered according to the supplied installation procedure. Adequate access is needed to apply heat around the required circumference and length without damaging adjacent cable materials or components.

Restricted access should be identified during work planning. The type of heating equipment, allowable cable preparation dimensions and component recovery sequence are determined by the installation instructions, not by a universal heating temperature or time.

After the individual conductor connections have received their required electrical insulation and screening treatment, the completed assembly must also have the specified outer protection. The exact function and sequence of the illustrated sleeves should be confirmed from the product-specific instructions.

The Material Schedule Should Include More Than the Joint Kit

A three-core joint may require conductor connectors, metallic screen restoration accessories, earthing or bonding components and provisions for the outer cable construction. The actual supply package must be agreed for the specified cable, particularly if armoured cable is involved.

The photo identifies the jointing product family but does not prove that every connector or earthing accessory is included in each size selection.

For project procurement: provide the cable datasheets for both ends, the proposed joint location, available working dimensions and installation environment. This allows the selected kit and accessory configuration to be reviewed before the cable is cut or the purchase order finalized.