2XSEYQY 6/10kV MV Tunnel Power Cable

2XSEYQY for Medium-Voltage Tunnel Distribution

2XSEYQY is a three-core 6/10 kV medium-voltage power cable developed for underground mining and tunnelling networks. It is used where transformers, main distribution panels, switchboards or approved equipment connections require screened XLPE-insulated cores together with substantial external mechanical protection.

Each phase core has inner and outer semiconductive field-control layers and an individual copper tape screen. The three screened cores are laid up with PVC filling, protected by a galvanized steel wire braid with at least 90% coverage, and finished with a red flame-retardant special PVC sheath. This layered construction supports electrical field control and physical protection in confined underground routes.

The cable uses IEC 60228 Class 2 conductors. It should therefore be selected as an armoured tunnel power cable rather than automatically treated as a continuous-flex reeling cable. Any moving-machine application must be checked against the bending cycle, movement frequency, tensile force, torsion and minimum mobile temperature stated for the project.

Key Engineering Features

• Three individually screened MV cores: Semiconductive layers smooth the electrical field around the XLPE insulation, while copper tape around each phase provides a defined metallic screen for field containment and the project earthing design.
• 90°C XLPE insulation system: XLPE supports a maximum conductor temperature of 90°C in normal operation and a stated short-circuit conductor temperature of 250°C.
• Class 2 copper conductors: Circular stranded plain annealed copper provides a stable power conductor for tunnel distribution. It is less flexible than Class 5 designs, which is important when comparing this cable with trailing or reeling alternatives.
• Minimum 90% GSWB coverage: The galvanized steel wire braid protects the laid-up screened cores against mechanical damage while allowing a round, compact construction. Armour continuity and termination must be included in the bonding design.
• Red flame-retardant PVC sheath: The visible red sheath supports route identification, while the supplied specification lists flame testing to the stated VDE, EN and IEC methods.
• Defined mechanical limits: Maximum tensile load is 15 N/mm² and maximum torsion is 25°/m. These limits must be considered together with pulling equipment, cable weight and route geometry.
• Six declared power sizes: Available data covers 3 × 25/16 through 3 × 120/16 mm², with diameter, 20°C conductor resistance and approximate weight for routing and handling calculations.

Technical Specifications

Cable Construction

1. Conductors: Circular stranded plain annealed copper, Class 2 according to IEC 60228.
2. Inner semiconductive layer: Extruded rubber semiconductive compound over the conductor for electrical field control.
3. Insulation: XLPE medium-voltage insulation.
4. Outer semiconductive layer: Extruded rubber semiconductive compound over the insulation.
5. Core identification: Natural insulation colour with a black semiconductive layer.
6. Metallic screen: Copper tapes applied around each main core.
7. Lay-up and bedding: Three screened cores laid up concentrically with PVC filler.
8. Armour: Galvanized steel wire braid with minimum 90% coverage.
9. Outer sheath: Red flame-retardant special PVC compound.

Applications

• Medium-voltage supply to underground mining and tunnelling transformers
• Main panels and switchboards in tunnel distribution networks
• Power routes in mines and underground excavations where screened cores and steel-wire-braid protection are required
• Stationary installations exposed to mechanical handling risks
• Connections to mobile operating equipment only where movement duty and bending conditions have been technically approved

Selection Notes for Buyers

Select the main conductor size from operating current, route length, permissible voltage drop, prospective short-circuit current, ambient temperature and installation method. Current capacity should be calculated according to DIN VDE 0298-4 for the actual route; the same conductor size can carry a different load when installed in air, ducts, trays, grouped runs or thermally restricted underground spaces.

The copper tape screen and galvanized steel wire braid require a documented bonding and earthing arrangement. Verify screen fault-current capacity, armour continuity, termination hardware and whether one-point or both-end bonding is required by the system design. The `/16` suffix is reproduced from the supplied size table; its exact screen or secondary-conductor definition should be confirmed on the approved construction drawing.

For mechanical planning, check the actual cable diameter, minimum bending radius, route changes, cable weight, pulling length, pulling-eye method and cleat spacing. Keep pulling load within 15 N/mm² and torsion within 25°/m. Because the conductor is Class 2 and the stated mobile temperature starts at +5°C, continuous reeling, high-cycle festoon service and cold-weather movement require a purpose-designed alternative unless separately approved.

An RFQ should state the system voltage, conductor size, route length, installation method, fault level and duration, bonding arrangement, movement duty, ambient temperature, hazardous-area documentation, required flame test, drum length and inspection documents.

Why Choose Tebaoflex

Tebaoflex supports medium-voltage tunnel projects with construction review, conductor-size coordination, production-length planning, drum packing, cable marking and technical document preparation. Quotations can be aligned with the required size, voltage, screen arrangement, armour, sheath colour and inspection scope so that contractors and equipment builders can compare the offered cable against their approved project specification.

FAQ

What is 2XSEYQY cable used for?

2XSEYQY is used for 6/10 kV power distribution to transformers, main panels, switchboards and approved equipment connections in mines, tunnels and underground excavations.

Is 2XSEYQY a flexible reeling cable?

It uses Class 2 stranded conductors and steel-wire-braid armour, so it should not automatically be specified for continuous reeling or high-cycle flexing. The movement duty must be checked for each installation.

How are the medium-voltage cores screened?

Each main core has inner and outer semiconductive field-control layers around the XLPE insulation, followed by an individual copper tape metallic screen.

What mechanical protection does the cable have?

A galvanized steel wire braid with minimum 90% coverage protects the laid-up screened cores beneath the red outer sheath.

What are the temperature limits?

The stated working range is -25°C to +80°C for fixed installation and +5°C to +80°C for mobile use. Maximum conductor temperature is 90°C.

Does use in a hazardous underground environment mean the cable is Ex certified?

No. The application description does not itself establish Ex certification. Required hazardous-area approvals and project documents must be confirmed before ordering.

What information is needed for a 2XSEYQY quotation?

Provide the size, length, route, current, short-circuit level, bonding method, movement duty, ambient temperature, drum requirement and required test or approval documents.