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Why do industrial cables need to be flame-resistant in power plants

Power plants stand as the backbone of modern energy supply, responsible for converting various energy sources (such as coal, natural gas, nuclear energy, and renewable energy) into electricity that powers industries, cities, and households. For a power plant to operate safely and continuously, every component in its system must meet strict performance and safety standards—including industrial cables. As the “nervous system” and “blood vessels” of a power plant, industrial cables are responsible for transmitting electrical energy, control signals, and data between key equipment such as boilers, turbines, transformers, and control rooms. However, the operating environment of power plants is extremely harsh and high-risk, with multiple potential fire hazards. This raises a critical question: Why do industrial cables in power plants must be flame-resistant?

1. The Unique Fire Risks in Power Plants: Why Industrial Cables Are a Key Safety Link

Power plants are filled with fire-prone factors that can easily ignite materials—especially industrial cables, which are widely laid across the entire plant (in cable trenches, tunnels, control rooms, and near high-temperature equipment). Understanding these risks is the first step in recognizing the need for flame-resistant industrial cables.

1.1 High-Temperature Equipment: A Persistent Ignition Source

Power plants house a large number of high-temperature operating equipment. For example, the surface temperature of a boiler’s furnace wall can reach 500–800°C, and the exhaust pipe of a gas turbine may exceed 600°C. Industrial cables routed near these devices are exposed to long-term radiant heat. If ordinary non-flame-resistant cables are used, their insulation and sheath materials (usually polymers like PVC or PE) will soften, melt, and even ignite at high temperatures. Once ignited, the cables will act as a “fire path,” spreading the flame to other areas of the plant.

1.2 Oil and Fuel Systems: Explosive Fire Triggers

Power plants rely heavily on oil and fuel systems. Transformers use insulating oil to cool and insulate; gas turbines run on natural gas or diesel; and lubricating oil systems keep rotating equipment (like turbines) operating smoothly. These oils and fuels are highly flammable. A small leak—caused by pipe corrosion, valve failure, or equipment damage—can form an oil film or vapor. If this comes into contact with a hot surface (such as an overheated industrial cable) or an electrical arc (from cable short circuits), it will immediately ignite. Ordinary industrial cables, when burned, will release a large amount of flammable gases, accelerating the spread of the fire and even causing explosions.

1.3 Electrical Faults: Direct Causes of Cable Ignition

Industrial cables in power plants carry high voltages (from low-voltage control signals to high-voltage power transmission, often up to 500kV or more) and large currents. Electrical faults such as short circuits, overloads, or poor contact are common triggers for cable fires. A short circuit can generate an instantaneous arc with a temperature of over 2000°C, which directly ignites the cable’s insulation layer. Overload causes the cable’s conductor to overheat, gradually melting the insulation material until it catches fire. In addition, aging or damaged cables (due to vibration, mechanical wear, or chemical corrosion) may expose their conductors, leading to arcing and ignition. Without flame-resistant properties, these ignited cables will quickly become a source of fire spread.

1.4 Combustible Dust and Materials: Amplifiers of Fire Hazards

Coal-fired power plants produce large amounts of coal dust, while biomass power plants handle flammable biomass materials (like wood chips or straw). These dusts and materials accumulate on the surface of industrial cables over time. When a fire breaks out (even a small one), the dust will burn rapidly, and the cables—if non-flame-resistant—will burn alongside the dust, turning a small local fire into a large-scale conflagration. Moreover, power plant buildings often use thermal insulation materials (such as foam or fiberglass), which are also flammable and can further fuel the fire if the cables ignite.

2. The Core Role of Flame-Resistant Industrial Cables: Protecting Power Plant Safety

Flame-resistant industrial cables are not just “fire-proof cables”—they are designed to mitigate the impact of fires in multiple ways, directly addressing the high-risk environment of power plants. Their role can be summarized in four key aspects:

2.1 Preventing Fire Spread: Containing Hazards to Local Areas

The most critical function of flame-resistant industrial cables is to stop the spread of fire. Unlike ordinary cables, which continue to burn and spread flame along their length once ignited, flame-resistant cables use specialized materials (such as flame-retardant additives or halogen-free flame-retardant polymers) and structural designs (like armored layers). When exposed to fire, these cables will self-extinguish within a short time (usually 30–60 seconds) after the ignition source is removed, rather than continuing to burn. This prevents the flame from spreading through the cable network to other parts of the plant—for example, stopping a fire in the boiler room from reaching the control room or cable tunnel, where it could cause more severe damage.

For instance, in a cable trench with hundreds of industrial cables, a single non-flame-resistant cable catching fire could ignite all adjacent cables in minutes, blocking the entire power transmission and control system. In contrast, flame-resistant cables would limit the fire to the initial ignition point, allowing firefighters to contain and extinguish it quickly.

2.2 Reducing Toxic Gas and Smoke: Protecting Human Life and Equipment

When ordinary industrial cables burn, their insulation and sheath materials (especially halogen-containing materials like PVC) release large amounts of toxic gases—such as carbon monoxide (CO), hydrogen chloride (HCl), and dioxins—and thick black smoke. In a power plant, most cable installations are in enclosed or semi-enclosed spaces (like cable tunnels, control rooms, or underground trenches). These toxic gases and smoke spread rapidly, making it impossible for on-site personnel to breathe or evacuate. HCl gas, for example, is highly corrosive; it can damage the respiratory tracts of workers and corrode sensitive electrical equipment (like circuit boards in control systems), leading to permanent equipment failure even after the fire is put out.

Flame-resistant industrial cables—especially halogen-free low-smoke (LSOH) flame-resistant cables—are designed to minimize this risk. They use halogen-free polymers (like XLPE or EPR) and flame-retardant additives (such as aluminum hydroxide or magnesium hydroxide) that release only small amounts of non-toxic or low-toxic gases when burned. The smoke density is also significantly lower, maintaining visibility in the fire area to help personnel evacuate safely and reducing corrosion damage to equipment.

2.3 Maintaining Critical Power Supply: Ensuring Emergency Response

During a fire, the continuity of power supply to critical systems (such as emergency lighting, fire-fighting equipment, and key control loops) is essential for minimizing losses. For example, fire pumps need electricity to spray water; emergency lights guide personnel to exits; and turbine control systems need to maintain power to shut down equipment safely (preventing secondary accidents like turbine overspeed).

Flame-resistant industrial cables are designed to maintain their electrical conductivity for a specified period (usually 1–2 hours) under fire conditions—this is known as “circuit integrity.” Even if the cable is exposed to high temperatures, its insulation layer will not immediately fail, ensuring that critical circuits remain operational. This gives firefighters enough time to control the fire and allows plant operators to execute emergency shutdown procedures, avoiding catastrophic failures (like boiler explosions or transformer oil fires).

2.4 Complying with Safety Standards and Regulations: Avoiding Legal and Operational Risks

All countries and regions have strict safety standards and regulations for power plants, which mandate the use of flame-resistant industrial cables. For example:

• The International Electrotechnical Commission (IEC) has standards like IEC 60332-3, which classifies cable flame resistance into Categories A, B, and C (with A being the highest level, requiring cables to resist fire spread in a vertical bundle).
• In the United States, Underwriters Laboratories (UL) has standards like UL 1685, which tests the flame resistance of cables in vertical and horizontal installations.
• In China, the national standard GB/T 18380 specifies flame resistance, smoke density, and toxic gas release requirements for cables used in power plants.

Using non-flame-resistant industrial cables not only violates these regulations but also leads to the rejection of power plant safety certifications (like ISO 45001 or local safety audits). This can result in fines, plant shutdowns, or even legal liability in the event of a fire. Flame-resistant cables ensure that power plants meet these mandatory requirements, avoiding operational and legal risks.

3. Technical Principles of Flame-Resistant Industrial Cables: How They Achieve Fire Safety

The flame-resistant performance of industrial cables is not achieved by a single material or design—it is the result of a combination of advanced materials, structural optimization, and strict testing. Understanding these technical principles helps power plant operators select the right cables for their needs.

3.1 Flame-Retardant Materials: The Foundation of Fire Resistance

The choice of insulation and sheath materials is the core of flame-resistant cables. Manufacturers use two main types of flame-retardant materials:

• Halogen-containing flame-retardant materials: These include PVC or PE modified with brominated flame retardants (like decabromodiphenyl ether) and antimony trioxide (a synergist). When burned, brominated flame retardants release bromine radicals that inhibit the combustion reaction, while antimony trioxide enhances this effect. However, these materials release HCl gas, so they are mainly used in open areas (like outdoor cable racks) where smoke and toxicity are less of a concern.
• Halogen-free low-smoke (LSOH) flame-retardant materials: These are the preferred choice for power plants, especially in enclosed spaces. They use polymers like cross-linked polyethylene (XLPE) or ethylene propylene rubber (EPR) mixed with inorganic flame retardants (like aluminum hydroxide or magnesium hydroxide). When heated, these inorganic additives decompose to release water vapor (which cools the cable) and form a dense ceramic-like carbon layer on the cable surface. This carbon layer blocks oxygen and heat, preventing the cable from continuing to burn. LSOH materials release no halogens, so smoke density and toxicity are drastically reduced.

3.2 Structural Design: Enhancing Fire Resistance and Durability

In addition to materials, the structural design of flame-resistant industrial cables plays a key role in their performance:

• Armored layers: Most flame-resistant cables for power plants include a steel tape or steel wire armored layer. This layer not only protects the cable from mechanical damage (like vibration or rodent bites) but also acts as a physical barrier against fire. Steel has a high melting point (over 1500°C), so it can resist high temperatures during a fire and prevent the flame from reaching the inner conductor and insulation.
• Filling and wrapping materials: The gaps between the cores of multi-core cables are filled with flame-retardant materials (like flame-retardant yarn or tape) instead of ordinary non-flame-resistant fillers (like jute). This prevents the filling material from catching fire and spreading the flame to other cores.
• Conductor design: The conductor (usually copper or aluminum) is made of high-purity metals with good thermal conductivity. This helps dissipate heat during normal operation, reducing the risk of overheating and ignition. Some high-voltage flame-resistant cables also use stranded conductors to enhance flexibility and reduce mechanical stress (which can damage the insulation layer over time).

3.3 Strict Testing: Ensuring Reliable Performance

To ensure that flame-resistant industrial cables meet standards, manufacturers subject them to a series of rigorous tests before they leave the factory:

• Flame resistance test: Cables are bundled (usually 3–7 cables) and exposed to a propane flame (with a temperature of 750–800°C) for a specified time (like 45 minutes). After the flame is removed, the cables must self-extinguish within 120 seconds, and the flame spread along the cable length must not exceed the standard limit (e.g., 1.5 meters for IEC 60332-3 Cat A).
• Smoke density test: Cables are burned in a closed chamber, and the smoke density is measured using a light transmittance meter. For LSOH cables, the minimum light transmittance must be above 60% (to ensure visibility during fires).
• Toxic gas release test: The types and concentrations of gases released during cable combustion are analyzed. For halogen-free cables, the concentration of HCl must be below 5 mg/g, and the concentration of CO must be below 1000 ppm.
• Circuit integrity test: Cables are exposed to a fire (with a temperature of 950–1000°C) while carrying a specified current. They must maintain electrical conductivity for at least 1 hour without short-circuiting or breaking.

4. Application-Specific Requirements for Flame-Resistant Industrial Cables in Different Power Plant Areas

Not all flame-resistant industrial cables are the same—different areas of a power plant have unique environmental conditions, so the choice of cables must be tailored to the specific location.

4.1 Boiler and Turbine Halls: High-Temperature and Oil-Resistant Cables

The boiler and turbine halls are the hottest areas of a power plant, with ambient temperatures often exceeding 50°C and surface temperatures of equipment reaching hundreds of degrees Celsius. Additionally, these areas have a high risk of oil leaks (from turbine lubricating systems or boiler fuel lines). For these locations, flame-resistant cables must meet two key requirements:

• High-temperature resistance: The insulation and sheath materials must withstand long-term exposure to high temperatures. XLPE-insulated cables (with a maximum operating temperature of 90–125°C) or EPR-insulated cables (with a maximum operating temperature of 105–150°C) are preferred.
• Oil resistance: The sheath material must be oil-resistant to prevent degradation from oil leaks. Materials like nitrile rubber (NBR) or chlorosulfonated polyethylene (CSPE) are commonly used.
• Flame resistance level: At least IEC 60332-3 Cat B or higher, to resist fire spread in the dense cable bundles near boilers and turbines.

4.2 Control Rooms and Switchgear Rooms: Low-Smoke and Low-Toxicity Cables

Control rooms house the power plant’s central control system (including DCS and PLC systems), while switchgear rooms contain high-voltage circuit breakers and transformers. These areas are enclosed, with a large number of personnel working there daily. The priority for cables here is:

• Halogen-free low-smoke (LSOH) properties: To minimize toxic gas and smoke release in the event of a fire, protecting personnel and sensitive electronic equipment.
• Flame resistance: IEC 60332-3 Cat A, as the cables are densely routed in cable trays above or below control panels.
• EMI resistance: Some control cables may also need electromagnetic interference (EMI) shielding (like copper tape or braid) to prevent signal interference—this shielding must also be flame-resistant.

4.3 Cable Tunnels and Trenches: Waterproof and Rodent-Resistant Cables

Cable tunnels and trenches are underground or semi-underground spaces that house hundreds of industrial cables (power, control, and communication cables). These areas are prone to water accumulation, humidity, and rodent infestations. For these locations, flame-resistant cables must have:

• Waterproof and moisture-resistant properties: The sheath material (like PE or XLPE) must be waterproof to prevent water from penetrating the insulation layer and causing short circuits.
• Rodent and termite resistance: The armored layer (steel tape or wire) or a special rodent-repellent sheath (like nylon) can prevent damage from rodents (which often chew through cables, causing faults).
• Flame resistance: IEC 60332-3 Cat A, with circuit integrity (to maintain power to emergency systems like tunnel ventilation fans during fires).

4.4 Outdoor Areas (e.g., Switchyards and Wind Turbine Bases): Weather-Resistant Cables

Outdoor areas of power plants (like high-voltage switchyards or wind turbine bases) are exposed to harsh weather conditions—rain, snow, UV radiation, and extreme temperatures (from -40°C in winter to 60°C in summer). Flame-resistant cables here must be:

• Weather-resistant: The sheath material must be UV-stabilized (to prevent degradation from sunlight) and low-temperature flexible (to avoid cracking in cold weather). Materials like PE or XLPE with UV additives are ideal.
• Flame resistance: IEC 60332-3 Cat C (for individual cables) or Cat B (for bundled cables), as outdoor fires are less likely to spread quickly but still require flame resistance.

5. The Consequences of Using Non-Flame-Resistant Industrial Cables in Power Plants

The decision to use non-flame-resistant industrial cables in power plants is not just a cost-saving measure—it is a critical safety risk that can lead to catastrophic consequences. Real-world cases and data highlight these dangers:

5.1 Economic Losses from Plant Shutdowns

A single fire caused by non-flame-resistant cables can shut down a power plant for days or even weeks. For example, in 2019, a coal-fired power plant in Southeast Asia experienced a cable fire in its turbine hall. The fire started when a non-flame-resistant control cable short-circuited and ignited, spreading to adjacent power cables. The fire destroyed 30% of the plant’s cable network, forcing a complete shutdown. The plant was offline for 10 days, resulting in a loss of 120 GWh of electricity (worth approximately \(5 million) and additional costs of \)2 million for cable replacement and equipment repairs.

5.2 Threats to Human Life

Toxic gases from burning non-flame-resistant cables are the leading cause of death in power plant fires. In 2017, a fire broke out in the cable tunnel of a European nuclear power plant (during a maintenance shutdown). The fire was caused by a non-flame-resistant cable that overheated. The burning cable released large amounts of HCl gas, which spread through the tunnel’s ventilation system. Six maintenance workers were hospitalized with severe respiratory injuries, and one worker died from toxic gas inhalation. Although the nuclear reactor was not damaged, the incident led to a 6-month safety audit and shutdown of the plant.

5.3 Damage to Critical Equipment

Non-flame-resistant cables, when burned, release molten insulation material that can drip onto other equipment (like transformers, circuit breakers, or control panels), causing secondary damage. For example, in a 2021 fire at a gas-fired power plant in North America, molten plastic from burning non-flame-resistant cables dripped onto a transformer’s oil tank, causing the tank to crack and leak insulating oil. The oil ignited, destroying the transformer (worth $1.2 million) and delaying the plant’s restart by 3 weeks.

5.4 Reputational and Legal Risks

Power plant fires caused by non-flame-resistant cables damage the plant operator’s reputation and lead to legal consequences. For instance, after the 2019 Southeast Asia power plant fire, the operator faced public criticism for cutting costs on safety equipment (including cables). Local regulators fined the company \(1 million and required it to replace all non-flame-resistant cables in the plant (at a cost of \)8 million). The operator also lost a long-term power supply contract with a major industrial client, leading to a 15% drop in annual revenue.

6. FRS: Your Trusted Partner for Flame-Resistant Industrial Cables in Power Plants

When it comes to ensuring the safety and reliability of power plants, choosing the right flame-resistant industrial cables is non-negotiable. FRS, a leading manufacturer of industrial cables with over 20 years of experience, is dedicated to providing high-quality, standards-compliant flame-resistant cables that meet the unique needs of power plants worldwide.

Why FRS Flame-Resistant Industrial Cables?

• Compliance with Global Standards: All FRS flame-resistant industrial cables are tested and certified to meet international standards, including IEC 60332-3 (Cat A/B/C), UL 1685, GB/T 18380, and IEEE 1207. Our cables are regularly audited by third-party organizations (like SGS and TÜV) to ensure consistent quality.
• Advanced Halogen-Free Low-Smoke (LSOH) Technology: FRS prioritizes the safety of personnel and equipment. Our LSOH flame-resistant cables release less than 3 mg/g of HCl and have a smoke density (light transmittance) of over 70%—exceeding industry standards. This makes them ideal for enclosed areas like control rooms and cable tunnels.
• Customized Solutions for Every Power Plant Area: FRS understands that different areas of a power plant have unique requirements. We offer a full range of flame-resistant cables, including:
• High-temperature XLPE/EPR-insulated cables for boiler and turbine halls (with operating temperatures up to 150°C and oil resistance).
• EMI-shielded LSOH cables for control rooms (to protect signal integrity).
• Waterproof, rodent-resistant armored cables for cable tunnels and trenches.
• UV-stabilized weather-resistant cables for outdoor switchyards and wind turbine bases.
• Rigorous Quality Control: FRS has a strict quality control process, from raw material selection to final product testing. Every batch of cables undergoes flame resistance, smoke density, toxic gas, and circuit integrity tests in our in-house laboratory. We also offer traceability—each cable is marked with a unique serial number, allowing customers to track its production and testing history.
• Comprehensive Support: FRS does not just sell cables—we provide end-to-end support. Our team of engineers works closely with power plant operators to assess their needs, recommend the right cable models, and provide technical documentation (like installation guides and certification reports). We also offer on-site installation supervision and after-sales maintenance services to ensure the cables perform optimally throughout their service life (which can exceed 25 years).

Partner with FRS for a Safer Power Plant

Whether you are building a new power plant, upgrading an existing one, or replacing aging cables, FRS has the flame-resistant industrial cables you need to protect your facility, personnel, and operations. Our commitment to safety, quality, and customization has made us a trusted partner for power plants in over 50 countries—including coal-fired, gas-fired, nuclear, and renewable energy plants.

Choose FRS flame-resistant industrial cables: Because in power plants, safety is not an option—it is a necessity.