1. Introduction to 19/33kV Medium Voltage Cables

The Medium Voltage Armoured Cable portfolio includes the 19/33(36)kV cables designed for power distribution networks. These cables are manufactured to standards including BS6622, BS7835, and BS7870-4.10, and are available as single core cables or three-core cables. The 19/33kV voltage rating represents the highest voltage class within the British Standard medium voltage range, serving critical infrastructure for national grid connections, industrial substations, and major commercial installations.

33kV cables are generally specified as underground mains power cables, supplied with Class 2 stranded copper conductors, although standards also allow for Class 1 solid and Class 2 stranded aluminium conductors which are available upon request. These cables are suitable for direct burial subject to relevant regulations, with armoured cables featuring MDPE, PVC, or LSZH sheathing providing additional mechanical protection where the installation environment demands it.

2. BS6622 XLPE PVC 19/33kV Armoured Cable

British Standard BS6622 sets out the specifications and required tests for armoured cables designed for use in fixed installations including networks and industrial installations. These cables feature single core AWA (Aluminium Wire Armour) and three core SWA (Steel Wire Armour) constructions with XLPE insulation and PVC or MDPE sheathing. The armour provides robust protection against mechanical stresses and potential damage from external forces, making these cables suitable for direct burial in the ground.

BS6622 Applications

BS6622 armoured cables are primarily used for underground power distribution networks. The robust construction allows for direct burial in free-draining soil without the need for additional mechanical protection. Common applications include industrial power distribution, utility networks, substation connections, and commercial building supplies where PVC or MDPE sheathing provides adequate environmental protection.

Source: Power & Cables – 33kV MV Cables

3. BS7835 XLPE LSZH 19/33kV Fire-Safe Cable

BS7835 is the Low Smoke Zero Halogen (LSZH) equivalent of BS6622, designed for installations where fire safety is paramount. These cables emit minimal smoke and no toxic halogen gases when exposed to fire, making them essential for tunnels, metros, airports, hospitals, and other public buildings where life safety is critical. The LSZH sheathing also provides a higher CPR (Construction Products Regulation) classification.

BS6622 vs BS7835 Comparison

Source: Eland Cables – MV Armoured Cable

4. BS7870-4.10 DNO-Standard Unarmoured Cable

British Standard BS7870-4.10 covers Copper and Aluminium medium voltage cables used for the foundation of electricity supply from a distribution main. BS7870 Part 4, Section 4.10 covers single core cables up to 19/33kV, with cables designed to connect sub-mains to local networks where the final connection occurs. These cables can be installed either by direct burial in the ground or in buried cable ducts.

BS7870-4.10 Variants at 19/33kV

5. UK DNO-Approved 33kV Cables

Eland Cables supplies a range of 11kV and 33kV DNO-approved cables manufactured by G81-approved suppliers for the UK distribution network operators including UKPN, SSE, National Grid Energy Distribution (NGED/WPD), Northern Power Grid (NPG), Scottish Power Energy Networks (SPEN), and Electricity Northwest (ENW). Any connection from the existing grid to new sub-main developments must use DNO specification cables manufactured by G81-approved suppliers.

DNO 33kV Cable Specifications

Sources: Eland Cables – UKPN Cable, Eland Cables – DNO Approved Cable

6. Complete 19/33kV Cable Comparison

7. Technical Specifications

Electrical Parameters

Source: Tratos Group – 33kV Cables

8. Applications & Installation Environments

33kV is one of the voltage ratings listed in IEC 60038 (IEC Standard Voltages) and is included in several British Standards. This voltage level is typically used in large medium voltage power distribution networks, between substations, local transformer stations, and industrial installations. The adoption of these standards ensures the safety, performance, and compatibility of electrical equipment and systems in the UK.

Installation Methods