Doncaster SWA Cable Construction Explained
Doncaster SWA cable construction explained: understanding the different layers of steel wire armoured cable helps electricians choose suitable products for underground, outdoor, commercial and industrial electrical installations. Doncaster Cables manufactures multicore SWA cables with copper conductors, XLPE insulation, protective bedding, galvanised steel wire armour and an outer sheath. This guide explains the role of each component, the differences between PVC and LSZH versions, core configurations and important installation considerations.
Doncaster SWA Cable Construction Explained – The Five Layers
Doncaster’s H694-XL is a commonly specified 600/1000V steel wire armoured cable manufactured to BS 5467. Its construction combines electrical insulation with mechanical protection and an outer environmental barrier.
The manufacturer’s construction is described as copper conductor, XLPE insulation, PVC bedding, galvanised steel wire armour and PVC sheath.
1. Copper Conductors
The conductors carry electrical current. Doncaster specifies plain annealed copper, Class 2 stranded to BS EN 60228, for its H694-XL range.
Class 2 stranded construction provides a practical conductor arrangement for fixed wiring applications. It should not be confused with the finer-stranded conductor construction used in many flexible cables.
2. XLPE Conductor Insulation
XLPE stands for cross-linked polyethylene. It is used to electrically insulate the individual conductors.
Doncaster specifies thermosetting XLPE insulation for the H694-XL cable, with a published maximum operating temperature of 90°C.
This rating does not automatically mean that every connected accessory or termination is suitable for 90°C operation. The complete circuit design, equipment temperature limits and installation conditions must be considered.
3. Protective Bedding
The bedding layer sits between the insulated conductors and the steel wire armour. It provides a protective separation and helps form the cable’s overall construction.
Doncaster H694-XL uses compatible polymeric bedding material, identified as PVC in the manufacturer’s construction specification.
4. Galvanised Steel Wire Armour
The steel wire armour provides mechanical protection for suitable fixed electrical installations.
Armour is particularly relevant where cables could be exposed to external mechanical forces, including certain underground installations and industrial environments.
The armour may also form part of the protective conductor arrangement when its electrical characteristics and termination method are suitable. This must be established by design and verified according to the applicable electrical installation requirements.
5. PVC Outer Sheath
The outer sheath provides protection to the cable’s internal construction and is intended for the environments specified by the manufacturer.
Doncaster H694-XL has a black PVC sheath. The manufacturer’s data confirms that this range is intended for suitable installations in air, on cable trays, clipped to surfaces, in concrete and underground.
Environmental suitability depends on the particular cable specification and installation conditions. Where exposure to chemicals, exceptional mechanical stress or other unusual conditions is expected, additional assessment is necessary.
Doncaster H694-XL SWA Cable Specifications
The H694-XL cable range is manufactured to BS 5467 and is specified for fixed wiring and mains distribution applications.
Its published characteristics include:
- Rated voltage: 600/1000V.
- Conductor material: plain annealed copper.
- Conductor construction: Class 2 stranded.
- Insulation: thermosetting XLPE.
- Bedding: compatible polymeric material.
- Armour: galvanised steel wire.
- Outer sheath: black PVC.
- Published minimum operating temperature: -15°C.
- Published maximum operating temperature: 90°C.
- Minimum bending radius: eight times the cable’s overall diameter.
These are manufacturer’s published characteristics for the H694-XL range. The actual outside diameter, weight, gland size and electrical characteristics vary by core count and conductor cross-section.
Consult the current Doncaster H694-XL product specifications for individual sizes.
Understanding SWA Cable Core Counts
Doncaster manufactures SWA cable in different core configurations. The number of cores determines how many insulated conductors are provided within the cable, but the appropriate arrangement depends on circuit design.
2-Core SWA Cable
Two-core SWA may be selected for suitable single-phase arrangements where the protective conductor requirements are separately satisfied.
Do not assume the armour can be used as the circuit protective conductor without checking its suitability and termination arrangements.
3-Core SWA Cable
3-core armoured cable is often considered for single-phase circuits where separate line, neutral and protective conductors are required.
However, standard three-core SWA conductor colours may be brown, black and grey, requiring correct identification and sleeving for the assigned functions.
4-Core SWA Cable
4-core armoured cable may be used for suitable three-phase arrangements or other circuit configurations.
The selected core functions, conductor identification and protective conductor arrangement must be consistent with the electrical design.
5-Core SWA Cable
5-core armoured cable provides additional insulated conductors for appropriate three-phase, neutral and protective conductor arrangements.
Doncaster’s published H694-XL five-core colour arrangement includes green/yellow, blue, brown, black and grey.
Always confirm the core colours and electrical requirements against the exact cable being ordered.
PVC vs LSZH SWA Cable – What Is the Difference?
When selecting Doncaster SWA cable, the sheath and insulation construction may be important for the installation environment and fire-performance specification.
PVC SWA Cable
Standard Doncaster H694-XL uses XLPE conductor insulation, compatible polymeric bedding and a PVC outer sheath.
PVC-sheathed SWA is widely used for suitable mains distribution, external wiring and fixed industrial installations.
Browse our PVC SWA cable selection for available configurations.
LSZH SWA Cable
LSZH stands for Low Smoke Zero Halogen. These cables use materials designed to reduce smoke emission and corrosive halogen-containing gas release under relevant fire-test conditions.
LSZH should not be confused with general low-smoke or low-smoke-and-fume descriptions. The exact cable construction, applicable standards and declared fire performance must be checked.
LSZH cable is not automatically fire-resistant or suitable for maintaining circuit operation during a fire.
Electrical4Less has separate categories for 2-core LSZH SWA, 3-core LSZH SWA, 4-core LSZH SWA, 5-core LSZH SWA and 7-core LSZH SWA.
Check the individual listing to confirm the actual manufacturer and construction rather than assuming every LSZH product is part of the same Doncaster H694-XL range.
Can Doncaster SWA Cable Be Buried Underground?
Doncaster confirms that its H694-XL SWA cable is intended for suitable underground installation, including direct burial or installation in ducts.
However, underground suitability depends on more than the cable’s armour.
The installation must consider:
- Expected mechanical damage and ground conditions.
- Appropriate burial depth for the location and risk.
- Suitable cable bedding and backfill where necessary.
- Relevant warning tape or identification arrangements.
- Thermal conditions affecting current-carrying capacity.
- The route, future excavation risks and other buried services.
- Correct protective conductor and fault-protection arrangements.
There is no single burial depth that can safely be assumed for every site. The design should follow the applicable regulations, ground conditions and expected external influences.
SWA armour provides mechanical protection but does not eliminate the need for correct installation or suitable protection against damage.
Doncaster SWA Cable Bending Radius and Installation Temperature
The minimum bending radius is important when routing SWA through bends, around equipment or into enclosures.
Doncaster lists a minimum bending radius of eight times the cable’s overall diameter for the H694-XL range.
For example, if a particular cable has an outside diameter of 20mm, a radius of eight times the diameter would be 160mm. The actual cable diameter must be taken from the correct product data sheet.
The manufacturer also publishes an operating temperature range. However, installation and handling temperatures may have different limitations from operating temperatures.
Do not force cable bends or assume that a heavy armoured cable can be handled in the same way as a flexible unarmoured cable.
SWA Cable Current Ratings and Voltage Drop
Choosing a conductor size requires more than looking at a cable’s nominal cross-sectional area.
The electrical designer must consider current demand, protective device characteristics, installation method, ambient temperature, grouping, voltage drop and fault protection.
Doncaster refers to BS 7671 current-carrying capacity data for its H694-XL cable range.
Long cable runs may require a larger conductor to satisfy voltage-drop limits even when the cable’s current-carrying capacity appears sufficient.
For example, a long supply to an outbuilding or EV charge point should be designed using the actual route length, load and installation conditions.
No fixed cable size can be recommended for every garage supply, EV charger or garden installation without the necessary design information.
Correct SWA Cable Glands and Armour Earthing
SWA cables require a suitable termination method for the armoured construction.
The selected gland must accommodate the cable’s bedding and armour dimensions and provide the necessary mechanical clamping and electrical continuity.
Depending on the environment and gland construction, appropriate products may include conventional BW or CW glands or specialist SWA termination systems.
Electrical4Less supplies SWA Cable Glands and selected specialist products through our Wiska Shop.
Protective earthing requirements must be determined by design. An earth tag, suitable earthing nut or another manufacturer-approved termination arrangement may be required.
Do not assume that every SWA cable needs the same earthing accessory, or that the armour is automatically adequate as a circuit protective conductor.
The completed termination must be electrically and mechanically suitable and verified as required.
Outdoor Junction Boxes and Cable Protection
Where Doncaster SWA cable terminates into outdoor equipment, the junction box or distribution enclosure must be appropriate for the environment.
Suitable products may include selected Wiska COMBI junction boxes or other enclosures designed for the required application.
The overall protection depends on the enclosure, glands, sealing accessories and installation method.
For example, an IP-rated gland does not automatically make a lower-rated enclosure suitable for immersion or underground use.
Ensure that the selected enclosure can accommodate the cable dimensions and required gland without compromising its construction.
Alternatives to SWA Cable
Not every installation requires steel wire armoured cable. Other cable constructions may be appropriate where the electrical and mechanical requirements permit.
Hi-Tuff Cable
Hi-Tuff Cable is an unarmoured cable product used for appropriate fixed wiring applications.
Its construction differs from SWA and should not be considered a direct substitute where steel wire armour is required for mechanical protection.
Read our Hi-Tuff Cable Guide for further information.
NYY-J Cable
NYY-J Cable is another unarmoured fixed wiring option available in different conductor configurations.
Some NYY-J products are suitable for direct burial under specified conditions, but their lack of steel wire armour means mechanical protection must be assessed separately.
Always check the specific manufacturer’s cable specification and the required installation method.
Typical Doncaster SWA Cable Applications
Depending on circuit design and environmental suitability, Doncaster steel wire armoured cable may be used for:
- Garage and outbuilding power supplies.
- Garden lighting distribution circuits.
- Commercial and industrial mains distribution.
- Workshops and plant installations.
- Supplies to selected outdoor equipment.
- Appropriate EV charging infrastructure.
- Cable routes on trays, ladders or other suitable containment.
Individual installation requirements, including protective devices, earthing arrangements and any RCD requirements, must be determined under the applicable regulations.
Doncaster Cables SWA Technical Data Sheet
Use the original Doncaster SWA data sheet below to examine the manufacturer’s construction and technical information. Always confirm that the document applies to the exact cable model and product size being specified.
The manufacturer also provides its official BS 5467 SWA technical data sheet and individual product specifications.
BS 7671 and Doncaster SWA Cable Installations
BS 7671:2018 Amendment 4:2026 is the current edition of the IET Wiring Regulations following the transition ending on 15 October 2026.
Correct electrical installation involves suitable cable selection, circuit design, protective conductors, cable routing, mechanical protection, appropriate termination and verification.
Using cable manufactured to BS 5467 does not automatically guarantee that a completed electrical installation complies with BS 7671.
For current guidance, refer to the IET information about BS 7671 Amendment 4:2026.
About Electrical4Less – Doncaster Cables and SWA Supplies
Electrical4Less Ltd is an independent electrical wholesaler based at 9 Seagrave Road, Fulham, London SW6 1RP. Our online catalogue includes SWA armoured cable, cable glands, junction boxes and other electrical installation materials.
We are members of the Independent Buying Association (IBA) and Electrical Distributors’ Association (EDA).
In 2026, Electrical4Less was a finalist for Website of the Year at the London Chamber of Commerce SME London Business Awards and shortlisted for Best Wholesaler (1–5 Branches) at the Electrical Wholesaler Awards.
Our range includes different core configurations and conductor sizes, with selected cables available by the metre. Customers can check current stock, request suitable quantities and arrange eligible order collection from our Fulham trade counter or UK delivery.
Visit our SWA Armoured Cable category or browse the Doncaster Cables product selection.
Frequently Asked Questions About Doncaster SWA Cable
Further SWA Cable Information
For current product information, visit our SWA Armoured Cable range, or consult Doncaster Cables’ official technical specifications before selecting an installation cable.
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