Medium Voltage Unarmoured Cable Selection Guide

To select medium voltage unarmoured cable, first confirm the system voltage, installation environment, conductor requirements, insulation type, and the mechanical protection available along the route. Unarmoured cable can be suitable for installations in ducts, conduits, cable trays, or controlled indoor areas when the design provides adequate protection against impact and crushing. It is not automatically suitable for direct burial or exposed locations. At Zhongdong Cable Co., Ltd., we recommend sharing your project specifications and installation details before requesting a quotation so we can help clarify the appropriate product requirements.

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Key Takeaways

Match the cable’s rated voltage to the network and applicable local standards, not just the nominal voltage stated in a brief inquiry.
Choose unarmoured construction only when the installation route offers adequate mechanical protection.
Specify conductor material and size, insulation, screen, sheath, temperature conditions, and required documentation.
Ask suppliers to confirm construction, compliance basis, quantity, production schedule, and shipping terms in writing.

Who This Guide Is For

This guide is intended for electrical contractors, project engineers, distributors, EPC companies, and procurement teams evaluating medium voltage cable for a defined project. It is especially useful when a specification calls for an unarmoured cable but does not fully describe the installation or protection measures. We focus on the decisions buyers should make before comparing quotations. Final cable selection should be reviewed against the project design and the standards applicable at the installation location.

What Is Medium Voltage Unarmoured Cable?

Medium voltage unarmoured cable is a power cable designed for medium voltage distribution circuits that does not include a metallic armour layer for mechanical protection. A typical construction may include a conductor, conductor screen, insulation, insulation screen, metallic screen, and an outer sheath, with exact layers depending on the design and governing specification. The word “unarmoured” describes the absence of armour; it does not mean the cable lacks electrical screening or a protective outer sheath. Buyers should confirm the complete layer arrangement rather than relying on the product name alone.

Voltage and Construction Context

Medium voltage classifications vary among markets and standards, so the project’s rated voltage notation must be checked carefully. For example, IEC 60502-2 addresses extruded-insulation power cables for rated voltages from 6 kV (Um 7.2 kV) up to 30 kV (Um 36 kV); this is a standard scope, not a claim that every project or product uses those ratings. Ask the design engineer or network owner to confirm the required U₀/U/U_m values and the applicable standard edition. We use those details to avoid quoting a cable that matches a broad voltage label but not the actual system requirement.

Types, Materials, and Specifications to Review

Conductor, Insulation, and Screen

Conductors are commonly specified as copper or aluminium, with size and conductor class selected according to load, voltage drop, short-circuit duty, installation conditions, and project rules. XLPE is a widely used medium voltage insulation material, while other constructions may be required by the design or local specification. Conductor and insulation choices affect electrical performance, weight, termination requirements, and total installed cost. A commonly specified maximum conductor operating temperature for XLPE-insulated cable is 90°C under defined normal operating conditions, but the applicable product standard and project design must confirm the rating.

Medium voltage designs generally use semiconductive screens around the conductor and insulation to manage the electric field, along with a metallic screen that supports grounding and fault-current requirements. Screen material and cross-section should be selected in coordination with the earthing design and the expected fault conditions. The outer sheath protects the cable from the environmental conditions specified for the route. Confirm whether requirements include resistance to moisture, sunlight, chemicals, or flame, rather than assuming these properties from the word “cable.”

Specification Checklist

Rated voltage and applicable standard, including any project-specific deviations.
Conductor metal, cross-sectional area, conductor class, and number of cores.
Insulation material, conductor and insulation screens, metallic screen design, and sheath material.
Installation method, ambient conditions, route length, bending requirements, and available mechanical protection.
Current-carrying load, voltage drop, short-circuit requirements, earthing approach, and termination compatibility.
Required inspection records, test documentation, marking, packing, and delivery destination.

Match the Cable to the Application

Unarmoured cable may be a practical option for protected routes such as enclosed ducts, conduits, or cable systems where the project design addresses mechanical risks. It can also be considered for indoor distribution routes when installation rules and the selected cable construction permit its use. The cable route matters as much as the cable itself: pulling conditions, supports, access, and exposure to other services can affect the selection. Confirm local installation requirements before treating any route as suitable.

For direct burial, areas exposed to vehicle traffic, or locations where impact and crushing are credible risks, do not assume that an unarmoured design is adequate. The project may require armour, a protective duct, concrete covering, or another engineered protection method. The right solution depends on the site conditions and applicable regulations, not on a blanket preference for one cable type. If the route changes during design, reassess the cable and protection arrangement before procurement.

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A Practical Selection Framework

1. Confirm the Electrical Design

Start with the system voltage, rated cable voltage, load current, fault level, and earthing requirements. Have the responsible electrical designer verify conductor sizing and screen requirements using the project’s operating and fault conditions. Do not select a cross-section from load current alone, because installation method and surrounding conditions also influence cable performance. Record all assumptions so the supplier can quote against a consistent specification.

2. Map the Installation Route

Describe whether the cable will be installed in a duct, conduit, tray, tunnel, building, or other route, and identify sections that may be exposed to mechanical or environmental hazards. Include route length, pulling conditions, ambient temperature, and any special entry or termination constraints. This information helps determine whether an unarmoured design is appropriate and whether additional route protection is required. Where conditions are uncertain, obtain a design review before finalizing the purchase specification.

3. Freeze the Construction and Documentation Requirements

Issue a cable data sheet or project specification covering conductor, insulation, screens, sheath, voltage rating, and standard. State required tests, inspection documents, drum lengths, marking, and packing preferences. If the project requires a particular approval or certificate, name it explicitly and confirm that the supplier can provide the requested evidence for the offered product. We encourage buyers to resolve deviations in writing before placing an order.

Price, MOQ, and Lead Time Considerations

Medium voltage cable pricing depends on factors such as conductor material and size, voltage rating, construction, order quantity, drum length, documentation, and delivery destination. Copper and aluminium options can produce different material costs and installation considerations, so compare equivalent technical specifications rather than headline prices alone. Minimum order quantities and production schedules vary by construction and order details. We provide project-based quotations after reviewing the required specification, quantity, and requested delivery schedule.

When comparing offers, check whether the quoted length is the total required length, how tolerance is handled, and whether accessories are included or excluded. Confirm the quotation validity period, packing arrangement, shipping terms, and any inspection requirements. A low initial price may not represent the same scope if the construction or documentation differs. Request a line-by-line technical confirmation to make commercial comparisons more reliable.

Supplier Evaluation Checklist

Can the supplier confirm the offered construction against your voltage, standard, and installation specification?
Will the quotation clearly identify conductor material, size, insulation, screens, sheath, and cable length?
Can the supplier state which inspection or test documents are available for the specific order?
Are production timing, minimum order conditions, packing, and delivery responsibilities clearly explained?
Is there a process for reviewing technical deviations and resolving questions before production?

At Zhongdong Cable Co., Ltd., we support B2B buyers by reviewing project requirements and clarifying the information needed for a suitable cable quotation. As a communication cable supplier, we do not assume that every medium voltage configuration is available or appropriate without checking the requested design and supply scope. Share your technical data sheet, target quantity, destination, and required delivery date so we can confirm what we can offer. Where a specification is incomplete, we can help identify the details that need confirmation before commercial evaluation.

Conclusion: How to Choose with Confidence

The best medium voltage unarmoured cable is the one that matches the electrical design, complies with the project’s applicable requirements, and is protected appropriately along its installation route. Confirm voltage, conductor, insulation, screens, sheath, fault conditions, and documentation before comparing supplier offers. Avoid specifying unarmoured cable for a mechanically exposed route unless the design includes a suitable protective measure. These checks provide a clear basis for evaluating both technical suitability and total procurement scope.

As a next step, send us your cable specification or project data sheet, estimated quantity, installation method, destination, and delivery target. We can review the information, clarify open technical points, and prepare a quotation for the requested scope. Contact Zhongdong Cable Co., Ltd. to discuss your medium voltage cable requirements and supplier evaluation questions.