Fires, smoke emissions and toxic fumes can pose a real threat to life and equipment in small, enclosed environments such as commercial or cruise ships. TOXFREE® Low Smoke Halogen Free (LSHF) submarine cables are manufactured and tested to the most demanding fire requirements. The standards applied to offshore installations are based on EN (European Standard) and IEC (International Electrotechnical Commission).
Flammability and fire propagation tests for submarine cables
Non-spread of flame Based on standard EN 60332-1 / IEC 60332-1
The test consists of placing a 60 cm piece of cable upright inside a cabinet, to avoid drafts, and applying a 1 kW caloric flame for 30 seconds. Once the heat source is cut off, the flame should self-extinguish while keeping the top intact, thus ensuring that the flame does not spread.
All submarine cables must meet minimum safety requirements, so that a short circuit does not cause a fire inside the ship.
Fire does not spread Based on EN 60332-3 / IEC 60332-3-22 (Cat. A)
The test consists of placing a number of 3.5 meter cables together in the vertical position of a large cabinet. At the base of the cable assembly, the flame is ignited by a propane burner for 20 minutes. Once the heat source is turned off, the remaining flame on the cables should self-extinguish while leaving the top of the cable intact, proving that the cable is not spreading flame spread.
Installing non-spreadable submarine cables that meet this test prevents the spread of local fire to other areas of the ship through the cable network.
Halogen free Based on EN-50267 / IEC 60754
The test consists of placing 1.0 grams of cable insulation in a laboratory oven and burning it. The released gases are chemically analyzed and their hydrochloric acid content, pH and conductivity are measured. The percentage of halogens present should be less than 0.5%.
By installing halogen-free insulation, you ensure that the toxicity of the gases released during a fire is reduced, thus reducing the risk of poisoning by inhalation.
Smoke opacity | Based on standard EN 61034 / IEC 61034-2
The test consists of burning a number of 1 meter cables in a 27 cubic meter cabinet. Multilateral trading system. The opacity of smoke is measured with a lamp of constant brightness and a photometer. Luminous transmittance should be greater than 60%.
By reducing the opacity of smoke in the event of a fire, rapid location of emergency exits and evacuation of the vessel is facilitated.
Fire resistance tests for submarine cables
Fire resistance | Based on IEC 60331-21
IEC 60331 specifies tests of electrical submarine cables for circuit integrity under fire conditions. It is divided into the following parts that describe the test modes, conditions and equipment used. Testing was originally performed only on fire alone for 180 minutes at 750°C. To better simulate real fire conditions, with mechanical stresses from falling materials and the presence of water, the test conditions were modified by changing the duration, increasing the flame temperature, and adding mechanical stresses and water spray.
The cable must be able to continue to supply power in the event of a fire, ensuring electricity to emergency circuits such as signal lights, smoke extractors, audible alarms, water pumps etc.
IEC 60331-1 ed 1.0 (2009-05) – Part 1: Shock fire test method at a temperature of not less than 830°C for cables with rated voltage up to and including 0.6/1 kV and with a total diameter exceeding 20 mm. IEC 60331-2 ed 1.0 (2009-05) – Part 2: Shock fire test method at a temperature of not less than 830 °C for cables with a rated voltage up to and including 0.6/1 kV and with an overall diameter not exceeding 20 mm. IEC 60331-3 ed 1.0 (2009-05) – Part 3: Shock fire test method at a temperature of not less than 830 °C for cables with rated voltage up to 0.6/1 kV and involving testing in a metal enclosure. IEC 60331-11 ed1.01 Console. With am1 (2009-07) – Part 11: Device – Fire alone at a flame temperature of at least 750 ° C. IEC 60331-12 ed1.01 Console. With am1 (2009-07) – Part 12: Device – Fire with shock at a flame temperature of at least 830 ° C. IEC 60331-21 ed1.0 (1999-04) – Part 21: Procedures and requirements – Cables with rated voltage up to and including 0.6/1 kV. IEC 60331-23 ed1.0 (1999-04) – Part 23: Procedures and requirements – Electrical data cables. IEC 60331-25 ed1.0 (1999-04) – Part 25: Procedures and requirements – Fiber optic cables. IEC 60331-31 ed1.0 (1999-04) – Part 31: Procedures and requirements for fire with shock – Cables with rated voltage up to and including 0.6/1 kV. IEC 60331-21/60331-23: A sample of 1200 mm long cable supported by two metal rings is installed horizontally in a special ventilated cabin. During the test, a voltage of nominal value is applied to the core of the cable wire (for communications cables it is equal to 110 V), thus creating a closed electrical circuit. The sample is subjected to the action of a linear gas burner with a length of 500 mm and a flame temperature equal to 750 °C to 800 °C. The duration of the fire is 180 minutes. The test result is considered positive if at that time it is not considered a short circuit in the circuit being investigated. IEC 60331-25: Details of the method for evaluating the circuit integrity of optical fiber cables. The standard specifies a ribbon burner and the recommended flame temperature is 750°C. The optical power meter is set to zero and changes in attenuation are monitored over the burner operating period of 180 minutes. The maximum change in attenuation (change from zero) is recorded over the period of burner application. In a period of 15 minutes after flame application, the maximum attenuation is also recorded. A test result is considered positive if it is not considered a short circuit in the circuit being tested at that time. IEC 60331-31: Applies to cables with a diameter greater than 20 mm, and provides standards and test procedures for cables exposed to fire and mechanical shock (equipment in accordance with IEC 60331-12). The test sample provides a cable segment length of at least 1500 mm. A U-shaped curved wire with a radius equal to the smallest allowed by the manufacturer, is mounted on a metal inspection ladder. During the study, an electric current of rated voltage is passed through all cable wires, and these cables are exposed to fire within 120 minutes, where the fire source is a gas burner set according to standards, as well as mechanical shock for 5 minutes. A test result is considered positive if at that time it is not considered a short circuit in the circuit being tested.
TOXFREE® MARINE cable range is one of the top cables
At Top Cable, we have been developing and manufacturing submarine cables for over 30 years. We have a full range of power, control, instrumentation and low voltage marine cables. All of them are available in armored and non-armored versions and also according to their fire performance: flame-resistant, fire-resistant, and fire-resistant.
TOP CABLE TOXFREE® marine cable assembly is the best solution for commercial ships, cruise ships, feeder ships, bulk bulwarks, tankers, drilling vessels, buoys, etc. For more information about our range of submarine cables, contact us today
