Author: Luke Publish Time: 21-10-2025 Origin: Site
Cables immune to fire hazards are the backbone of all key construction systems - they hold the assurance that even in the worst of fire conditions, alarm, communication lines, and emergency lighting are kept active. What stands behind the demonstration for a cable's ability to hold up against flames, water, and mechanical strain in an actual fire?
Let us give you a tour through the fire examination testing room, where Zion Communication's cables undergo the world's best tests: BS 6387, EN 50200, and BS 8434.
During this test, we do not only burn a cable, but we see if it can still conduct current and keep its insulation while being exposed directly to fire, water spray, and mechanical impact.
We develop such tests by simulating real-life emergencies in tunnels, high-rise buildings, airports, or data centers, where maintaining operation of critical systems is vital for the evacuation of the public and for firefighting.
This British Standard categorizes cables into three endurance tests, each representing a distinct hazard environment:
Category | Condition | Description | Duration |
Cat C | Fire | Cable exposed to 950 °C gas flame for 3 hours while energized at rated voltage. | 180 min |
Cat W | Fire + Water | Flame at 650 °C combined with water spray jets to simulate sprinkler systems. | 15 min |
Cat Z | Fire + Mechanical Shock | Cable receives hammer impacts (1 per 30 s) during combustion to simulate falling debris. | — |
A cable passing all three categories (CWZ rating) demonstrates the highest level of protection, qualifying it for use in emergency alarm, PA, and evacuation systems.
This European standard assesses the cable’s circuit integrity during fire and vibration.
Flame temperature: 842 °C
Test duration: 120 min
Mechanical stress: Continuous oscillation and hammering every 30 seconds
Pass criteria: Cable must maintain power to a 230 V circuit throughout the full 2 hours
Cables that achieve the PH120 rating are ideal for critical European infrastructure such as hospitals, metros, and control centers.
This test is carried out to verify circuit integrity during a fire.
The cable is exposed to a flame at 930°C and mechanical shocks for 60 minutes and additional 60 minutes to flame, Mechanical shocks and water spray.
A typical fire cable laboratory looks like a high-security furnace chamber equipped with:
Gas burners calibrated to maintain 950 °C ± 40 °C
Impact hammers delivering strikes every 30 seconds
Water spray nozzles arranged at 45° angles for uniform coverage
Voltage monitoring units recording circuit continuity in real time
Thermocouples and infrared sensors for precise temperature control
The laboratory is enclosed with refractory bricks and metal shielding to ensure stable combustion and prevent external airflow interference.
So, the cable is energized at the standard voltage ratings, usually 230 or 600 V. The laboratory measures:
Continuity: The circuit has to be constantly active till when off condition takes place.
Insulation Resistance (IR): The insulation should still have minimum IR value (generally ≥ 1 MΩ/km) after it has been cooled.
Dielectric Strength: Acquired through confirming post-test high-voltage withstand testing.
This shows that the cable can deliver power safely even when subjected to fire, water, and mechanical stresses — an absolutely vital characteristic in case of emergency evacuation routes.
Zion Communication's cables are subjected to an extensive in-house and third-party verification process that includes:
Pre-Test Preparation: To ensure insulation’s stable physical use, each sample is conditioned in controlled humidity and temperature.
Test Execution: A horizontally-mounted sample without the precise bending radius is installed using calibrated BS 6387 test rigs. The test is equipped with real-time current and voltage sensors to track any interruptions during the test.
Multi-Stage Evaluation: Zion's engineers examine, IR measure, and perform voltage breakdown testing, including the impact, when the task of validating endurance is accomplished by Spacecraft.
Third-Party Certification: Zion cables are tested and certified to BS 6387 CWZ, EN 50200 PH120, BS 8434-2, and IEC 60331. Well-reputed and internationally recognized labs do these to ensure compliance with the governing boards of LPCB, BSI, and IEC.
Quality Traceability:
Every batch carries a unique test record and date-coded sheath printing, ensuring traceability from raw material to final product shipment.
In real-world scenarios, the difference between compliance and failure can be measured in seconds that save lives.
Fire-resistant cables tested under BS 6387 and EN 50200 conditions ensure that:
Emergency alarms remain active
Evacuation lighting stays on
Communication and control systems function reliably
Toxic smoke emission is minimized (LSZH materials)
Zion Communication continues to improve material science and test automation to enhance cable performance under extreme fire conditions — proving that safety is engineered, not assumed.
✅ Key Takeaways
BS 6387 (Cat C/W/Z): Fire + Water + Shock sequence, 950 °C flame, highest protection rating.
EN 50200 (PH120): 842 °C flame, mechanical vibration, 120 min continuity.
BS 8434-2: Adds water spray to verify post-fire functionality.
Zion Communication: Ensures full compliance, third-party certification, and traceable quality control.
Luke Han is a Product Manager and Director at Zion Communication,
Specializing in fire, security, and alarm solutions. With extensive industry experience,
Dedicated to delivering high-performance, reliable products that are tailored to customer needs.
luke@zion-communication.com
0086 19883212162