IEC 60331 Fire-Resistance Cable Burning Test Apparatus

The Fire-Resistance Cable Burning Test Apparatus (Cable Fire Integrity Tester) is designed to evaluate the ability of mineral-insulated cables and cables with fire-resistant layers to maintain circuit integrity under flame exposure. The apparatus subjects the test sample to a controlled gas flame under specified temperature, time, and electrical loading conditions, monitoring for short circuits or open circuits. This allows assessment of the cable’s fire-resistance performance. The system is suitable for type tests, factory inspections, and research verification of fire-resistant cables.

Cables, as critical carriers for power transmission and information communication, have flame-retardant performance that is directly related to the safe operation of multiple sectors, including construction, transportation, energy, and telecommunications. Cable combustion test equipment is a core tool used to evaluate the ability of cables and optical cables to resist flame propagation under specified fire conditions and to determine their combustion characteristics.Conducting this type of testing plays an irreplaceable role in preventing major safety accidents caused by cable fires and in ensuring the safety of life and property. It is not only a key step in quality control for cable products, but also an important basis for ensuring compliance with national mandatory safety regulations and industry standards, as well as meeting stringent fire safety requirements in specific applications such as subways, high-rise buildings, and nuclear power plants.At the same time, this testing also provides a scientific evaluation foundation for new material development and advances in fire protection technology.

Basic Functions of a Cable Fire Resistance Testing Machine

The primary function of a cable fire resistance testing machine is to simulate a fire environment and evaluate the fire resistance performance of electrical wires and cables. The specific test items include:

(1) Fire Resistance Duration:

Records the time during which the cable maintains functional integrity under high temperature or flame exposure.

(2) Combustion Characteristics:

Observes the burning rate of the cable, flame propagation behavior, and whether dripping particles are produced during combustion.

(3) Smoke Emission:

Measures the smoke density generated during the combustion process and evaluates its impact on visibility and the surrounding environment.

(4) Insulation Performance:

Tests whether the insulation resistance of the cable after the fire exposure meets the required standards.

Applications

Based on practical applications of domestic and international fire-resistant and flame-retardant cable testing equipment, this apparatus is suitable for the following products and scenarios:

Mineral-insulated cables (MI cables)

Power cables with fire-resistant layer structures

Fire-resistant building wires

Low-voltage control and signal cables

Fire-resistant optical fibers and composite cables

Fire-resistant cables rated ≤ 450/750 V

Verification of fire, flame-retardant, and water-resistant fire performance

Applicable users include cable manufacturers, electrical inspection agencies, fire safety product testing centers, research institutes, and third-party laboratories.

Standards

The apparatus is designed to comply with and support the following standards:

GB/T 19216-2008 — Test methods for cable or optical fiber circuit integrity under flame conditions

GB/T 19666-2019 — General requirements for flame-retardant and fire-resistant wires and cables

IEC 60331-2009 — Tests on electric cables under fire conditions

BS 6387 — Performance requirements for maintaining circuit integrity of cables under fire conditions

BS 8491 — Assessment methods for fire-resistance of cables

Technical Specifications

Product Features

Mass flow controllers enable high-precision closed-loop control of gas and air flow.

Wide flame temperature adjustment range meets different fire-resistance test requirements.

Circuit integrity detection via breaker replaces traditional fuse structures, improving maintenance efficiency.

Continuous live monitoring system detects open or short circuits in real-time.

Side-mounted exhaust system ensures stable oxygen levels during combustion.

PLC + touchscreen control allows intuitive parameter settings and excellent test repeatability.

Compatible with multiple fire-resistance test modes, including water-spray fire-resistance and mechanical impact tests.

Accessories and Consumables

Testing Principle

During the test, the mass flow controller precisely adjusts the gas-to-air ratio, producing a stable and controllable high-temperature flame. The test cable is subjected to continuous flame while all cores are energized at rated voltage and a load current close to 0.1 A.

A continuous monitoring system observes the circuit status in real-time. Any short-circuit or open-circuit condition triggers an immediate signal, allowing evaluation of whether the sample maintains circuit integrity under the specified flame and loading conditions.

Operation Instructions

Ensure all gas lines, air lines, and exhaust systems are properly connected before testing.

Set the gas flow, air flow, and test duration according to the relevant standard.

Activate the exhaust system before ignition to ensure combustion gases are removed.

Do not open the test chamber door during testing.

For water-spray or water-jet fire tests, calibrate the flow meters and verify the tray setup before ignition.

Core Advantages of the Cable Fire Resistance Test System

The core advantages of a fire-resistant cable combustion test system lie in its precise simulation of fire conditions, ensured compliance of circuit integrity testing, and improved testing efficiency and safety. These advantages are reflected in the following aspects:

High-Precision Flame Control:

The system uses strip or tube-type propane burners (e.g., 500 mm length with three rows of Φ1.32 mm holes), combined with a mass flow controller and a Venturi mixer, to maintain a stable flame temperature of 750 ± 50°C (Class B) or 950–1000°C (Class A), in full compliance with standards such as GB/T and IEC requirements.

Real-Time Circuit Integrity Monitoring:

Equipped with a 0–1000 V adjustable load power supply and a continuity monitoring circuit (LED/current alarm), the system continuously monitors whether the cable remains electrically conductive during combustion. It automatically determines the “power maintenance duration” (e.g., 90 minutes), and the data can be synchronized to a computer for curve generation and report output.

Automation and Safety Design:

Supports both manual and automatic operation modes, with features such as automatic gas shutoff, high-capacity exhaust (≥3000 m³/h), grounding protection, and a tempered glass observation window. High-end models may integrate thermocouple calibration systems and touchscreen controls to reduce human error.

Multi-Standard Compatibility:

A single system can comply with multiple testing standards such as GB/T, BS, and IEC. By replacing burners or adding modules such as water spray or impact systems, the equipment can be flexibly expanded for different test requirements.

Robust Structure and Easy Operation:

The combustion chamber is typically made of 304 stainless steel with insulated aluminum silicate fiber lining. The specimen holder uses a metal ring and grounded support structure to ensure accurate horizontal positioning (error ≤ ±10 mm). Quick-connect gas pipelines and corrosion-resistant protective gloves further enhance repeatability and operator safety.