Fire-rated cables play a vital role in building safety, particularly in fire prevention and protection. In New Zealand, stringent regulations, such as the Building Code Clause C – Protection from Fire, set clear fire safety standards for building design and construction.1 Fire-rated cables help meet these requirements by preventing electrical wiring from spreading flames and ensuring critical systems remain operational during a fire.
AS/NZS 3000:2018 (Wiring Rules) specifies electrical wiring standards across various building types, mandating fire-rated cables in high-risk environments like hospitals, schools, and high-rise buildings.2 In these settings, the failure of essential systems—such as emergency lighting, fire alarms, and sprinklers—could have catastrophic consequences. Fire-rated cables are engineered to withstand extreme conditions, maintaining power to these life-saving systems when they are needed most.
Beyond regulatory compliance, fire-rated cables provide an added layer of security, protecting both lives and property. By preventing electrical systems from fueling a fire, they reduce risk, liability, and potential financial losses. In the event of a fire, they can also simplify insurance claims and improve overall safety outcomes. Investing in fire-rated cables isn't just about meeting codes—it's about safeguarding the future.
How will fire-rated cable react during fire conditions?
Fire-rated cables are specially engineered to withstand extreme heat and maintain functionality during a fire. While they are engineered to resist flames, it's important to note that they are not entirely fireproof. These cables are typically made from materials like ceramic, mica, or low-smoke halogen-free compounds - designed to minimise toxic smoke emissions and reduce the risk of fire spreading.3 In the event of a fire, they play a crucial role in preserving the integrity of electrical systems.
One of the defining features of fire-rated cables is their ability to keep critical systems running for a specified duration—ranging from 30 minutes to several hours—depending on their fire rating. These ratings (e.g., 30, 60, or 90 minutes) indicate the period during which the cables can endure high temperatures while maintaining power.4 This capability is essential for ensuring that fire alarms, emergency lighting, and other safety systems remain operational when they are needed most.
Although fire-rated cables will eventually degrade beyond their rated time, they are designed to fulfill their primary purpose: sustaining life-saving systems long enough to aid evacuations and emergency response efforts. By the time they begin to break down, they will have already contributed to safeguarding lives and minimising damage.
How do fire-rated cables perform under fire conditions?
Fire-rated cables are engineered to withstand extreme conditions, ensuring that critical systems stay operational when it matters most. Their insulation is crafted from high-performance fire-resistant materials like ceramic, mica, or low-smoke halogen-free compounds. These materials don’t just resist combustion, they actively prevent flames from spreading along the cable, providing crucial time for evacuation and emergency response.
Inside, the conductors—typically copper or aluminum—are sometimes coated with additional fire-resistant layers to enhance durability. Even under intense heat, these conductors are designed to maintain their electrical integrity, keeping essential circuits functional during a fire.
Unlike standard cables, fire-rated cables won’t propagate flames along their length. Instead, the specialised insulation acts as a protective barrier, stopping fire in its tracks. However, while it is engineered to perform in fire conditions, it isn’t indestructible. After its rated fire-resistance duration, the insulation may degrade, becoming brittle or melting—but by then, it already served its vital purpose: sustaining life-saving systems.
Many fire-rated cables are also halogen-free, meaning it produces minimal smoke and doesn’t release toxic gases when exposed to flames. This significantly reduces the risk of poisoning and improves visibility, making evacuations safer in a fire emergency.5
Are fire-rated cables and flame-retardant cables the same?
Fire-rated and flame-retardant cables are not the same, although they share a common purpose of enhancing fire safety. The key difference lies in their performance in fire conditions, the materials used, and their intended applications.
Fire-rated cables are designed to continue operating during a fire for a specified period - depending on the specific fire rating (such as 30 minutes, 60 minutes, or 90 minutes). Its primary function is to ensure that critical systems (e.g., fire alarms, emergency lighting, smoke control systems) remain operational during a fire, allowing time for safe evacuation and firefighting efforts.6
Flame-retardant cables are designed to reduce the spread of fire along the cable but are not necessarily built to maintain function during a fire. They prevent the cable from igniting and propagating flames to other parts of the building or structure.6
The key differences between the two are:
- Fire-rated cables are designed to maintain functionality for critical systems during a fire, whereas flame-retardant cables are intended to slow or prevent the spread of fire.
- Fire-rated cables undergo fire-resistance tests, while flame-retardant cables are tested for flame propagation resistance. 6, 7
- Fire-rated cables are used in more critical safety applications (emergency systems, fire alarms), while flame-retardant cables are typically used in general electrical installations to limit the spread of fire.
While both types of cables are designed to enhance safety in the event of a fire, fire-rated cables provide a higher level of protection by maintaining system functionality, whereas flame-retardant cables focus on slowing the spread of fire.
Which electrical installations are fire-rated cables suitable for?
Fire-rated cables play a crucial role in maintaining the functionality of essential systems during a fire. These specialised cables ensure that life-saving equipment continues to operate when it matters most. Here are some key areas where fire-rated cables are indispensable:
- Fire-rated cables keep escape lighting, emergency lighting, and exit signs operational, ensuring safe evacuation routes remain visible in an emergency.
- Reliable fire-rated wiring ensures fire alarms function without interruption, providing early warnings that save lives.
- From ventilation systems to sprinklers, fire-rated cables ensure that smoke and heat management systems continue to operate, reducing fire spread and improving safety.
- These cables support fire suppression systems, ensuring that sprinklers activate and function properly to control flames.
- In healthcare settings, data centers, and high-rise buildings, fire-rated cables maintain power to backup generators and essential systems, preventing dangerous disruptions.
- Multi-storey offices, high-rise buildings, and major infrastructure projects rely on these cables to keep fire alarms, emergency systems, and other critical functions running under fire conditions.
- Power distribution centers (e.g., substations and electrical rooms) require fire-rated cables to prevent fire-related power failures that could compromise control systems.
- In hospitals, nursing homes, and other public spaces, these cables support life-saving equipment, emergency lighting, and fire alarms, ensuring continuous protection for occupants.
Fire-rated cables are a critical component of fire safety, ensuring that essential systems remain operational in emergency situations. In New Zealand, stringent regulations like the Building Code Clause C and AS/NZS 3000:2018 (Wiring) mandate their use in high-risk environments to enhance building resilience and occupant safety. By preventing electrical failures during a fire, these cables protect lives, reduce property damage, and support firefighting efforts. Whether in hospitals, high-rise buildings, or public spaces, investing in fire-rated cables is not just about compliance—it’s about ensuring the safety and continuity of critical infrastructure when it matters most.
Active Electrical Suppliers Ltd partners with leading cable distributors in New Zealand to offer a range of cables. Click here to learn more about what AS/NZS3013 fire-rated cable is available from your local branch.
by Sean Aucamp, 15 April 2025
References:
1 Building Code Clause C – Protection from Fire
2 AS/NZS 3000:2018 (Wiring Rules)
3 What are fire-resistant cables and their applications?
4 Cable fire ratings and what they mean
5 Halogen-free cables and wires - How, what, when and, above all, why?
6 Flame retardant vs fire resistant cables – what’s the difference?
