Description

Elsewedy 3-Core Unarmored Copper Cable Joint, (35+16) mm², 1 kV

Introduction: Connection Engineering for (35+16) mm² Copper Conductors

In electrical power distribution, cables with cross-sections such as35 mm²are widely used to feed sub-distribution boards in residential buildings, shops, and street-lighting systems. A critical point in these networks is the joint, which must carry continuous current that may exceed120 Aand withstand significant thermal stress during short-circuit conditions.

The Elsewedy joint for(35+16) mm²is not merely an insulating cover; it is an integrated system designed to rebuild the unarmored cable’s electrical insulation, mechanical protection, and moisture seal while maintaining stable connection points against moisture-related oxidation.

Chapter One: Engineering Structure and Three-Layer Protection System

Elsewedy joints use advanced radiation-crosslinked polymer technology and consist of technical layers that work together to rebuild the unarmored cable:

1. Industrial-Grade Phase Insulation Tubes

The kit includes four heavy-wall polymer tubes, three for35 mm²and one for16 mm², each heat-shrinking individually over a copper conductor.

• Technical Performance:These tubes provide high dielectric strength to help prevent electrical arcing between adjacent phases. The material is designed to resist stress cracking caused by thermal expansion of the35 mm²conductor during sustained full-load operation.

2. Active Hot-Melt Sealing Technology

The inner and outer tubes are lined with a dense layer ofactive hot-melt adhesive.

• Critical Function:When the joint is heated, the adhesive becomes semi-fluid and flows into gaps around the copper strands. For copper, this seal helps prevent moisture ingress that can promote corrosion and raise electrical resistance, leading to progressive joint heating and deterioration.

3. Heavy-Duty Outer Protective Sleeve

A large heavy-wall outer tube that acts as a protective barrier against external conditions.

• Features:The sleeve is designed to resist UV exposure, soil acids, and alkalis. It also provides additional mechanical protection that compensates for the absence of metallic armor in this cable type and helps protect the buried joint against minor impact and environmental corrosion.

Chapter Two: Technical Challenges and Elsewedy Solutions for 35 mm² Copper

1. Managing Thermal Stress Under Continuous Load

A copper conductor with a cross-section of35 mm²can generate significant heat under full load. Any increase in joint resistance can turn the connection point into a thermal weak spot in the system.

• The solution:Elsewedy polymer tubes are manufactured for stable dielectric and thermal performance, helping manage heat while maintaining insulation integrity at elevated cable operating temperatures.90°C.

2. Mechanical Expansion in Unarmored Cables

Because the cable is unarmored, it lacks an internal metallic structure that restricts longitudinal movement. Thermal expansion of copper can therefore produce noticeable cable movement under changing loads.

• The solution:Elsewedy tubes retain elastomeric flexibility and continue to compress around the cable, forming a dynamic seal that follows mechanical movement without losing the moisture barrier or creating gaps during repeated heating and cooling cycles.

Chapter Three: Joint Applications in Critical Projects

This joint is used where stable power transmission is important:

• Residential Buildings and Villas:For joining riser cables feeding sub-distribution boards.

• Farms and Rural Areas:For supply networks requiring protection against soil moisture and changing weather conditions.

• Street-Lighting Systems:Where reliable moisture sealing is needed for joints installed near lighting poles.

• Small Workshops:For networks using copper cables to minimize voltage drop and support long service life in underground distribution systems.

Chapter Four: Technical Installation Guide

To support a service life exceeding30 years, the following installation protocol should be followed for this conductor size:

1. Conductor Preparation:Clean the copper strands35 mm²thoroughly to remove oxidation using suitable cleaning materials such as alcohol wipes, then dry them completely.

2. Mechanical Connection:Use manual or hydraulic crimping with dies correctly matched to35 mm²and16 mm²to compress the strands uniformly and expel air from the connector.

3. Heat Distribution:Heat the tubes evenly in a circular motion from the center toward the ends to expel trapped air and reduce voids that can contribute to internal partial discharge.

4. Chemical Cleanliness:Ensure the joint area is free of dust and oil before heat shrinking so the active adhesive can bond effectively.