Table of Contents
Key takeaways
- "4 core × 25 sq. mm" gives core count and conductor area only, not voltage, material, insulation or armour.
- Core count shows how many conductors exist; phase and neutral roles come from the approved design.
- Sq. mm measures conductor area only; overall diameter must be taken from the datasheet.
- Conductor material must be stated explicitly, since equal core count and sq. mm do not make cables equivalent.
- Confirm phase and neutral areas for 3.5 core cables before ordering.
Armoured cable specifications that look identical on two quotations can still describe different cables. Both may read “4 core × 25 sq. mm” yet differ in conductor material, insulation or armour, so careful reading before comparing prices prevents approving the wrong product.
Core count and sq. mm identify key parts of a cable but neither define the complete product nor prove it suits a circuit. This guide explains how to read descriptions of Aluminium Armoured Cables and Copper Armoured Cables listed by Capital Cables India Pvt. Ltd.
Procurement teams, estimators and junior engineers can use it to check cable core count, cable cross sectional area, conductor material and size chart columns before sending an enquiry for Aluminium and Copper Armoured Cables.
Reading Armoured Cable Specifications by Core Count and Size
A description such as “4 core × 25 sq. mm” normally means four conductors, each with a nominal cross sectional area of 25 sq. mm, unless the product documentation states otherwise. Core count precedes the multiplication symbol and conductor area follows it.
Illustration 1: Annotated notation example (illustrative notation only, not a listed Capital Cables product; schematic, not to scale)
| Notation part | Example entry | What it tells the buyer |
| Core count | 4 | Number of insulated conductors inside the cable |
| Multiplication symbol | × | Separates the core count from the conductor area |
| Conductor area | 25 sq. mm | Nominal cross sectional area of each conductor, unless the documentation states otherwise |
| Not conveyed | Not stated | Voltage grade, conductor material, insulation, armour type, sheath and applicable standard |
Suppliers abbreviate descriptions differently, so the same notation may hide different constructions. Buyers should check how the datasheet defines each entry rather than rely on the abbreviated description alone.
Engineer’s note
Before comparing prices, read the conductor material, core count, phase and neutral areas and overall diameter from the datasheet, not from the abbreviated description alone. Confirm the phase and neutral arrangement against the approved design.
Cable Core Count and Phase and Neutral Conductors
Core count tells the buyer how many conductors exist, not what each one does. Phase, neutral and protective functions are assigned by the approved circuit design and the drawings that support it.
A three core or four core cable can therefore serve different conductor arrangements on different projects. Colour identification on the cores, the single line drawing and the specified arrangement must agree before the cable is ordered.
Armour provides mechanical protection, but its use as a protective conductor is a design decision. Buyers should not assume armour satisfies that role in every installation unless the approved design and applicable rules confirm it.
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Aluminium 3.5 Core Armoured Cable and Reduced Neutral Notation
A 3.5 core designation commonly describes three phase conductors of the stated area plus a neutral conductor of smaller area. It is a configuration label, not three full conductors and a physically half formed fourth core.
The designation alone does not state the neutral area, and reduced neutral sizes vary between phase sizes and products. Buyers requesting a 1.1KV Aluminium 3.5 Core Armoured Cable should confirm the actual phase and neutral areas from the specific Capital Cables product documentation.
A reduced neutral arrangement needs design approval because it is not automatically suitable for every load. The enquiry should then state the approved neutral area in sq. mm alongside the phase area.
Cable Cross Sectional Area Versus Overall Diameter
Sq. mm describes the conductor cross sectional area only. Overall cable diameter is a separate dimension expressed in mm and includes every layer built around the conductors.
Illustration 2: Conductor area versus overall diameter (schematic, not to scale; layer order shown for a typical armoured construction)
| Cable layer | Contributes to | Unit used |
| Conductor | Conductor cross sectional area | sq. mm |
| Insulation | Overall diameter | mm |
| Inner sheath or bedding | Overall diameter | mm |
| Armour | Overall diameter | mm |
| Outer sheath | Overall diameter | mm |
Only the first row appears in a “core × sq. mm” description. Gland size, duct fit and bending space depend on the finished dimensions, so buyers should take the overall diameter from the datasheet.
Two cables with the same conductor area need not share an outside diameter. Insulation type, voltage grade, conductor shape and armour construction all change the finished size.
Read nextIdentifying Conductor Material in Aluminium and Copper Armoured Cables
Conductor material should appear in three places: the product title, the conductor line of the datasheet and the purchase order description. Capital Cables lists aluminium and copper armoured power cables as separate products, which makes the material visible at the listing stage.
The term copper conductor identifies the conductor material; the armour material must be checked separately. Buyers should not assume every metallic component in a Copper Conductor Armoured Cable is copper.
Equal core count and equal sq. mm do not make an aluminium product electrically equivalent to a copper one. The approved design specifies the conductor material, and the order should state it explicitly rather than leave it implied.
Reading an Armoured Cable Size Chart
An armoured cable size chart lists the configurations a manufacturer offers. Buyers should read only the columns the chart actually includes and request a datasheet for any detail it leaves out.
Table: Interpreting common size chart columns (a reading guide, not product data; confirm which columns appear in the relevant Capital Cables size chart)
| Column heading | How to read it | If the column is absent |
| Number of cores | Core configuration, such as 3, 3.5 or 4 | Confirm from the product title |
| Nominal conductor area (sq. mm) | Phase conductor area; check whether a neutral area is listed separately | Request phase and neutral sizes in writing |
| Overall diameter (mm) | Finished outside dimension for gland and route planning | Request it before selecting glands |
A size chart shows what is available. It does not replace assessment of load, installation conditions, voltage drop or fault performance, which belong to the approved design.
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Aluminium and Copper Armoured Cable Application Examples
The scenarios below are general illustrations of interpretation issues, not applications stated by Capital Cables. Each one focuses on a different question the description leaves open.
Example 1: Aluminium 4 Core Armoured Cable for a distribution feeder. The description confirms four aluminium conductors of one stated area. The buyer still needs the designer’s assignment of phase, neutral and protective functions before placing the order.
Example 2: Aluminium 3 Core or 3.5 Core Armoured Power Cable for a three phase supply. The description shows whether a neutral is included. The buyer must confirm whether the load needs a neutral and, for 3.5 core, which neutral area the design approves.
Example 3: Copper Armoured Power Cable entering a panel. The description gives conductor material and area. Before selecting a cable gland, confirm the cable’s specified overall diameter, armour construction and compatible gland requirements from the product documentation.
Capital Cables and Armoured Cable Specification Enquiries
Capital Cables offers wires and cables, including a power and control cables range with aluminium and copper armoured options. These listed products give buyers a reference point for matching enquiry wording to an actual product description.
To request a quotation that matches the approved design, include these details when contacting Capital Cables:
- Conductor material
- Core configuration, including phase and neutral arrangement
- Phase and neutral conductor sizes in sq. mm
- Required voltage grade
- Applicable standard
- Insulation, armour and sheath construction
- Required lengths
Attaching the approved cable schedule or drawing reference keeps the enquiry tied to one specification and makes clarification questions quicker to resolve.
Confirming Armoured Cable Specifications Before Ordering
Before issuing a purchase order, compare the proposed cable description with the approved specification and supporting product documentation. Share the confirmed requirements with Capital Cables India Pvt. Ltd. for a product enquiry, while leaving cable sizing and installation approval to the responsible project engineer.
Frequently asked questions
Does "4 core × 25 sq. mm" mean all four conductors are the same size?
Normally yes, it means four conductors each with a nominal cross sectional area of 25 sq. mm, unless the product documentation states otherwise. Check the datasheet to confirm how the supplier defines the entry.
What does a 3.5 core armoured cable mean?
It commonly describes three phase conductors of the stated area plus a neutral of smaller area. The designation alone does not state the neutral area, so confirm it from the product documentation.
Is sq. mm the same as the cable’s outside diameter?
No. Sq. mm describes only the conductor cross sectional area, while overall diameter in mm includes insulation, sheath, armour and other layers. Take the overall diameter from the datasheet for gland and duct planning.
Can the armour be used as the earth conductor?
Not automatically. Using armour as a protective conductor is a design decision, so buyers should only assume this if the approved design and applicable rules confirm it.
What should I send when requesting a quotation for armoured cables?
Include the conductor material, core configuration with phase and neutral arrangement, phase and neutral sizes in sq. mm, voltage grade, applicable standard, construction details and required lengths. Attaching the approved cable schedule or drawing reference helps.
Summary
Core count and sq. mm identify only part of an armoured cable, so buyers should also check conductor material, phase and neutral areas, and overall diameter. Confirm the arrangement against the approved design and request missing details in writing before ordering.
