3.6/6kV, 6/10kV, 8.7/15kV XLPE Insulated, LSOH (SHF1) Sheathed, Armoured Flame Retardant MV Power Cables (Halogen Free Inner Covering)

8.7/15kV

In the realm of electrical engineering, particularly within maritime and offshore industries, the choice of power cables is paramount to ensuring operational safety, reliability, and environmental compliance. Medium voltage (MV) power cables, such as those rated at 3.6/6kV, 6/10kV, and 8.7/15kV, play a critical role in transmitting electricity aboard ships and in fixed installations where harsh conditions prevail. This article delves into the specifics of XLPE insulated, LSOH (SHF1) sheathed, armoured flame retardant MV power cables featuring a halogen-free inner covering. These cables are designed to meet stringent international standards, offering flame retardancy, low smoke emission, and halogen-free properties that are essential in confined spaces like ship compartments.

Cross-linked polyethylene (XLPE) insulation has revolutionised cable technology by providing excellent electrical properties, thermal stability, and resistance to moisture. Combined with low smoke zero halogen (LSOH) sheathing, specifically SHF1 type, these cables minimise toxic gas release during fires, enhancing crew safety. The armouring adds mechanical protection, while the flame retardant characteristics prevent fire propagation. Drawing from South African perspectives, where maritime trade and shipbuilding are vital to the economy—think of ports like Durban and Cape Town—these cables align with global best practices while addressing local regulatory needs under bodies like the South African Maritime Safety Authority (SAMSA).

Applications in Maritime Settings

These armoured MV cables are primarily engineered for use on board ships in all locations for fixed installations, as per IEC 60092-352 standards. Their design caters to environments where fire hazards are a constant threat, such as engine rooms, cargo holds, and navigation bridges. The flame retardant, low smoke, and halogen-free attributes make them ideal for confined spaces where smoke inhalation or corrosive gases could exacerbate emergencies.

In South Africa, with its extensive coastline and bustling ports, these cables find relevance in vessels operating in the Indian and Atlantic Oceans. For instance, in the fishing industry off the Western Cape, where trawlers face salty, humid conditions, the XLPE insulation ensures long-term dielectric strength, preventing breakdowns that could lead to power outages at sea. Similarly, in offshore oil and gas platforms near Mossel Bay, the armoured construction protects against mechanical stresses from vibrations and impacts.

The halogen-free inner covering further enhances safety by eliminating the release of halogens like chlorine, which can form hydrochloric acid in fires, corroding equipment and harming personnel. This is particularly advantageous in passenger ships or ferries servicing routes between Durban and Mozambique, where passenger safety is non-negotiable.

Compliance with International Standards

Adherence to rigorous standards is a hallmark of these cables. They comply with IEC 60092-350/351/354/359 for general construction and testing of shipboard cables. Flame retardancy is verified through IEC 60332-1 (single cable) and IEC 60332-3-22 (bunched cables), ensuring they do not propagate fire. Low smoke emission is tested per IEC 61034, while halogen-free properties are confirmed via IEC 60754-1/2, which measures acidity and halogen content in combustion gases.

In a South African context, these standards align with SANS (South African National Standards) equivalents, such as SANS 60092 series, facilitating seamless integration into vessels built or refitted in local shipyards like those in Saldanha Bay. This compliance not only meets international maritime organisation (IMO) requirements but also supports insurance and classification society approvals from bodies like Lloyd's Register or Bureau Veritas, which are common in South African maritime operations.

Advantages:

The core characteristics of these cables—XLPE insulation, LSOH sheathing, armouring, and flame retardancy—confer multiple advantages.

Electrical Performance: XLPE's high insulation resistance (>1000 MΩ·km) and low dielectric loss (tan δ < 0.004) ensure efficient power transmission. The semi-conducting screens reduce electric stress, minimising ageing. Compared to PVC-insulated cables, XLPE offers better overload capacity, handling 130% rated current for hours.

Fire Safety: Flame retardant per IEC 60332, these cables self-extinguish, preventing fire spread. LSOH (SHF1) limits smoke density to <60% transmittance and halogen content to <0.5%, reducing visibility loss and toxicity. In a fire scenario on a South African cargo ship, this could mean the difference between controlled evacuation and catastrophe.

Environmental and Health Benefits: Halogen-free inner covering eliminates corrosive emissions, protecting electronics and human health. This aligns with South Africa's environmental regulations under the National Environmental Management Act, promoting sustainable maritime practices.

Mechanical Durability: Copper wire braid armour withstands >1000N crush force and tensile loads, ideal for dynamic ship environments. It also provides EMC shielding, reducing interference in sensitive navigation systems.

Installation and Maintenance Ease: Flexible stranding and colour-coded cores simplify handling. The broad temperature range suits global shipping, from Antarctic research vessels to equatorial traders.

Advantages over alternatives: Unlike EPR-insulated cables, XLPE is lighter and cheaper while maintaining performance. Versus non-armoured types, these offer superior protection in hazardous zones.

Applications in South African

Consider a hypothetical refit of a bulk carrier at the Durban shipyard. The vessel, servicing iron ore exports, required MV cables for its electrical upgrade. Opting for 6/10kV three-core 3×95mm² cables (part no. 6/10KV-3C95, 60.8mm diameter, 5900kg/km), the installation enhanced power distribution to cranes and pumps. The LSOH sheathing proved vital during a simulated fire drill, emitting minimal smoke and allowing quick response.

Another example: An offshore supply vessel operating from Cape Town for the oil fields. Using 8.7/15kV single-core 1×185mm² cables (8.7/15KV-1C185, 39.3mm, 3180kg/km), the armoured design resisted wave-induced vibrations, preventing faults. Post-installation, maintenance logs showed zero breakdowns over two years, attributing success to XLPE's moisture resistance in salty air.

In the renewable sector, these cables could power floating wind farms off Algoa Bay, where flame retardancy mitigates risks from electrical arcs.

The 3.6/6kV, 6/10kV, and 8.7/15kV XLPE insulated, LSOH (SHF1) sheathed, armoured flame retardant MV power cables with halogen-free inner covering represent a pinnacle of cable technology for maritime applications. Their construction ensures safety, efficiency, and durability, making them a wise choice for South African and global shipping. By prioritising these cables, industries can mitigate risks, comply with standards, and foster sustainable operations. As maritime electrification advances, these innovations will undoubtedly play a starring role.