Medium Voltage Underground Cable for Distribution Networks

An underground feeder must match its electrical load and the conditions along its route. Soil, ducts, groundwater, nearby circuits, and installation space can all affect the cable design.

Therefore, purchasing medium voltage underground cable requires more than a voltage rating and conductor size. Buyers also need to confirm insulation, metallic screens, mechanical protection, accessories, and inspection requirements.

Shenghua Cable Group manufactures medium voltage armored cables for industrial and utility distribution. Its published range includes copper and aluminum conductors, XLPE insulation, and several protective constructions.

For utilities, EPC contractors, and industrial buyers, the following steps help turn a cable schedule into a clear manufacturing specification.

Define the Network and Installation Route

Start with the electrical system. Confirm the cable voltage designation, system earthing arrangement, fault conditions, and required service duty.

Next, describe how each route section will be installed:

• Direct burial

• Underground ducts

• Concrete trenches

• Cable tunnels

• Indoor equipment connections

• Outdoor transitions

A single feeder may pass through several environments. Consequently, the design should consider the most demanding section rather than use one general current rating for the entire route.

Also identify water exposure, chemical contamination, and restrictions on joint locations before requesting a quotation.

Select Copper or Aluminum Conductors

Copper and aluminum are both used in medium voltage distribution. The appropriate choice depends on electrical performance, available space, handling, and connection requirements.

Copper can provide a more compact conductor for a given electrical duty. Aluminum offers lower conductor weight, although it generally needs a larger cross-section for comparable performance.

Shenghua’s YJV22 copper conductor cable and YJLV22 aluminum conductor cable illustrate these options.

Compare complete installed designs. Include cable diameter, joint and termination costs, pulling arrangements, and compatible conductor connectors. A lower cable price per meter may not produce the lowest overall project cost.

Size the Cable for Buried Conditions

Current capacity depends on how effectively heat moves away from the cable. A rating calculated for open air cannot be transferred directly to a buried installation.

Provide the design engineer with:

• Required continuous current

• Soil temperature

• Soil thermal resistivity

• Burial depth

• Circuit spacing and grouping

• Duct dimensions and materials

• Cable arrangement

• Expected load pattern

Voltage drop and short-circuit duty also require review. The selected conductor must satisfy the project’s electrical requirements under the approved installation conditions.

Where a route includes a crowded duct bank or a thermally difficult section, check whether that section limits the feeder capacity.

Understand Screens, Armor, and Sheaths

These cable layers perform different jobs.

Semiconductive screens control electrical stress around the insulation. The metallic screen forms part of the designed earthing and fault-current arrangement.

Armor provides mechanical protection. The outer sheath separates the internal construction from the surrounding environment.

Therefore, specify each layer separately. The metallic screen should have a defined material and cross-section, while its bonding arrangement should follow the system design.

Likewise, armor selection should reflect the cable configuration and mechanical risks. Single-core AC cables require particular care when selecting armor and nearby metallic components.

Match Protection to the Ground Conditions

An armored cable is not automatically suitable for every underground environment.

Review the need for water-blocking features, sheath resistance, duct protection, and suitable bedding. Where water exposure is expected, identify whether the requirement concerns damp soil, flooded ducts, or another condition.

Also distinguish protection against mechanical damage from protection against moisture penetration. A metal armor layer alone does not establish a watertight construction.

Before approval, request a construction drawing showing all required protective layers. This makes it easier to compare quotations and identify omitted features.

Coordinate Joints and Terminations Early

Medium voltage accessories must match the cable being supplied.

Share the following dimensions with the accessory manufacturer:

• Conductor size and construction

• Insulation diameter

• Screen type

• Metallic screen dimensions

• Overall cable diameter

• Sheath and armor details

Confirm the accessory’s voltage rating and installation requirements as well.

For example, a conductor change from copper to aluminum may affect connector selection. A change in insulation diameter may also move the cable outside an accessory’s approved range.

Approving cable and accessories together can prevent delays after delivery.

Set the Applicable Standard and Test Plan

IEC 60502-2 covers construction, dimensions, and testing for extruded-insulation power cables within its stated medium voltage range. However, buyers should confirm that the exact voltage designation and offered construction fall within the specified standard’s scope.

For other voltage ratings or market requirements, identify the appropriate governing standard separately.

The purchase documents should also state the required edition and acceptance criteria.

An agreed inspection plan may include conductor resistance, dimensional checks, partial discharge testing, voltage testing, and sheath checks, as applicable. Separate routine production tests from type-test evidence.

Request reports that identify the tested cable construction. A general certificate should not replace product-specific technical approval.

Plan Drum Lengths Around Installation Limits

Longer cable lengths can reduce joints, but they also increase drum size and handling demands.

Review transport access, drum weight, lifting equipment, pulling tension, bends, and available joint bays before confirming production lengths.

Each drum should have a clear destination within the route. Include the cable item number, supplied length, batch reference, and planned installation section on the identification schedule.

Finally, agree on end sealing and transport protection. Inspect drums and cable ends when they arrive, before releasing them for installation.

Prepare a Complete Inquiry for Shenghua

For an accurate proposal, send Shenghua Cable Group:

• Cable voltage designation

• Conductor material and cross-section

• Number of cores

• Load and fault requirements

• Installation and ground conditions

• Metallic screen specification

• Armor and sheath requirements

• Water-blocking requirements

• Applicable standards

• Total quantity and drum lengths

• Required documents and inspection scope

• Destination and delivery schedule

Include the route drawing, cable schedule, and accessory requirements where available.

Shenghua’s medium voltage cable range provides options for utility feeders and industrial distribution. A clearly approved specification helps align manufacturing, inspection, delivery, and site installation from the start.