Fire Survival Cables (FS Cables)

What are Fire Survival Cables?

Fire survival cables, are specialized cables designed to maintain their functionality in the event of a fire. These cables are made of materials that are highly resistant to heat and flames, and they are capable of maintaining their electrical integrity even when exposed to extreme temperatures.

The primary purpose of fire survival cables is to ensure the continued operation of critical electrical circuits during a fire. This is particularly important in buildings where the failure of electrical systems could have catastrophic consequences, such as hospitals, airports, and high-rise buildings.

Fire survival cables are typically constructed with special materials, such as mineral insulation or ceramic compounds, that are highly resistant to fire and heat. Additionally, fire survival cables are often coated with fire-retardant materials to prevent the spread of flames in the event of a fire.

It's worth noting that while fire survival cables are designed to maintain their functionality during a fire, they are not indestructible. In extreme cases, even fire survival cables may fail, so it's important to take appropriate precautions, such as installing fire suppression systems and ensuring that all electrical systems are properly maintained and inspected.

Generic design of a fire survival cable

1. Conductor: The conductor is the central component of the cable and is typically made of copper or aluminum, for FS cables copper is used as the conductor due to higher melting point of copper at 1085°C.
2. First layer of mica tape: The first layer of mica tape is helically wound over the condcutor in one direction. This layer helps to provide additional insulation and fire resistance. Melting point of mica tape is around 1200 ~ 1300°C.
3. Second layer of mica tape: The second layer of mica tape is helically wound over the first layer in the opposite direction. This creates a cross-hatched pattern that helps to prevent the conductor from cracking or breaking under stress.
4. Insulation: The insulation is typically made of a Poly Vinyl Cholride. This layer provides thermal insulation.
5. Inner Sheath: This layer is also typically made of Fire Resistant Low Smoke Zero Halogen Poly Vinyl Cholride and it provides additional thermal insulation and heat resistance property to the cable.
6. Armor layer: The armor layer is a metal moslty galvanised steel wire or strip which provides mechanical protection for the cable.
7. Sheathing layer: The sheathing layer is the outermost layer of the cable and is typically made of a fire-retardant material, such as Fire Resistant Low Smoke Zero Halogen Poly Vinyl Cholride. This layer provides additional protection against fire and environmental hazards.

The grade of materials used in each layer of the cable will depend on the specific application and standards to be met. For example, cables designed for use in high-temperature environments may require more heat-resistant insulation and mica tape, while cables designed for use in harsh chemical environments may require specialized sheathing materials. The materials used in fire survival cables must also comply with various industry standards and regulations, such as UL 2196, IEC 60331, and BS 6387.

What are the advantages of Fire Survival Cables?

Fire survival cables offer several advantages over conventional cables, particularly in critical applications where safety is a primary concern. Here are some of the key advantages of fire survival cables:

1. Fire resistance: Fire survival cables are designed to resist the effects of fire, including high temperatures, flames, and smoke. This makes them ideal for use in critical applications where fire safety is a primary concern, such as emergency lighting, fire alarms, and sprinkler systems.
2. Electrical integrity: Fire survival cables are designed to maintain their electrical integrity and function during a fire. This is important in critical applications where the failure of electrical systems could lead to serious consequences, such as loss of life or property damage.
3. Durability: Fire survival cables are designed to be durable and reliable in harsh environments, including extreme temperatures, moisture, and chemicals. This makes them ideal for use in industrial and marine applications where the cables may be exposed to harsh conditions.
4. Flexibility: Despite their high level of fire resistance, fire survival cables are typically designed to be flexible and easy to install. This makes them ideal for use in applications where the cables may need to be routed through tight spaces or around corners.
5. Compliance: Fire survival cables are designed to comply with various industry standards and regulations, such as UL 2196, IEC 60331, and BS 6387. This ensures that they meet the necessary requirements for fire resistance and electrical performance, and can be safely used in critical applications.

What are the disadvantages of fire survival cables?

While fire survival cables offer many advantages in terms of fire resistance and electrical integrity, there are also some potential disadvantages to consider. Here are a few:

1. Cost: Fire survival cables can be more expensive than conventional cables due to the use of specialized materials and manufacturing processes required to provide their fire resistance and electrical performance.
2. Performance: While fire survival cables are designed to maintain their electrical integrity during a fire, their performance may still be affected by high temperatures and other factors. This can potentially impact their reliability in certain critical applications.
3. Availability: Depending on the specific application and requirements, fire survival cables may not be readily available in certain sizes or configurations, which can limit their suitability for certain projects.

What are the testing applicable on fire survival cables?

Fire survival cables are subject to various testing procedures to ensure their fire resistance and electrical performance. Here are some of the most common tests that are applicable to fire survival cables:

1. Fire resistance test: This test measures the ability of the cable to withstand fire conditions, including exposure to high temperatures, flames, and smoke. The most common fire resistance tests for fire survival cables include the IEC 60331 and BS 6387 standards, which involve subjecting the cable to fire conditions for a specified period of time and measuring its electrical integrity before and after the test.
2. Circuit integrity test: This test measures the ability of the cable to maintain its electrical performance during a fire. The most common circuit integrity tests for fire survival cables include the IEC 60331-21, BS 6387 and UL 2196 standards, which involve subjecting the cable to fire conditions and measuring its electrical performance over time.
3. Mechanical testing: This test measures the cable's ability to withstand physical stress, such as bending and twisting, without compromising its fire resistance or electrical performance. The most common mechanical tests for fire survival cables include the IEC 60794-1-2 and IEC 60811-2-1 standards, which involve subjecting the cable to various mechanical stresses and measuring its performance.
4. Chemical testing: This test measures the cable's ability to withstand exposure to various chemicals and substances without compromising its fire resistance or electrical performance.

What are the applications of Fire Survival Cables?

Fire survival cables are designed for use in critical applications where fire safety is a primary concern. Here are some of the most common applications of fire survival cables:

1. Emergency lighting: Fire survival cables are often used to provide power to emergency lighting systems, which are critical for safe evacuation in the event of a fire.
2. Fire alarms: Fire survival cables are commonly used in fire alarm systems, which are designed to detect and alert occupants of a building in the event of a fire.
3. Sprinkler systems: Fire survival cables are often used to power the pumps and controls in automatic sprinkler systems, which are designed to help control and extinguish fires.
4. Data centers: Fire survival cables are commonly used in data centers, where they provide power and connectivity to critical equipment, such as servers and networking devices.
5. Oil and gas industry: Fire survival cables are commonly used in the oil and gas industry, where they are exposed to harsh environmental conditions and the risk of fire and explosion is high.
6. Marine industry: Fire survival cables are commonly used in the marine industry, where they are exposed to harsh environmental conditions and the risk of fire is high.

Overall, fire survival cables are used in a wide range of critical applications where fire safety and electrical integrity are of paramount importance.