Electrical and electronic devices must adhere to strict safety standards, including resistance to high temperatures. Under heat exposure, the properties of non-metallic and insulating materials may degrade, leading to softening or melting, increasing the risk of failure or hazards to users. The ball pressure test is a precise method used to evaluate the heat resistance of materials under elevated temperatures.
The significance of heat resistance
Heat resistance is a critical requirement in testing standards such as:
- PN-EN 60598-1:2021 – applicable to lighting fixtures.
- PN-EN 60335-1:2024 – applicable to electrical appliances for household and similar use.
According to these standards, external parts made from insulating material that protect against electric shock, as well as components supporting conductive elements or SELV (Safety Extra Low Voltage) parts, must be sufficiently heat-resistant. Degradation of their structural properties can lead to non-compliance with safety standards.
Ball pressure test: method for heat resistance evaluation
The ball pressure test is a standard method for assessing the heat resistance of non-metallic and insulating materials. It involves pressing a steel ball of a specified diameter onto the surface of the tested material under constant load and at a controlled temperature. After the test, the indentation diameter is measured to determine if the material meets heat resistance requirements.
Standard: PN-EN 60695-10-2
The ball pressure test is detailed in the PN-EN 60695-10-2:2014-10 standard, titled “Fire hazard testing – Part 10-2: Abnormal heat – Ball pressure test.”. This standard defines the method for evaluating material resistance to excessive heat by assessing their softening temperature and ability to withstand load under elevated temperatures.
This method is used for materials in electrotechnical devices, such as plugs, sockets, transformers, power supplies, and switches.
Test procedure
The ball pressure test is conducted as follows:
- Sample preparation:
- The sample is cut from the product to obtain an element at least 2.5 mm thick with parallel upper and lower surfaces.
- If this is not feasible, a piece of the same material with a thickness of 3.0 mm ± 0.5 mm can be used.
- Sample conditioning:
- The sample is conditioned in an environment with a temperature between 15°C and 35°C and relative humidity of 45% to 75% for at least 24 hours.
- Test execution:
- The sample is placed in an oven heated to the required temperature (125°C for conductive or SELV parts, and 75°C for other parts).
- A steel ball with a 2.5 mm radius and a force of 20 N is applied to the sample’s surface.
- After one hour, the sample is removed and cooled in water at 20°C ± 5°C for six minutes.
- Result evaluation:
- After cooling, the indentation diameter is measured.
- If the indentation diameter does not exceed 2.0 mm, the material is considered heat-resistant.
Temperature requirements
The standard specifies different testing temperatures based on the purpose of the tested parts:
- 125°C – for parts supporting conductive or SELV components.
- 75°C – for other non-metallic or insulating parts.
Applications of the ball pressure test
The ball pressure test is applicable to a wide range of products, including:
- Plugs and sockets.
- Transformers and chokes.
- Power supplies.
- IT equipment.
- Device switches.
Safety standards for these products clearly define heat resistance requirements for materials, and performing the ball pressure test is a crucial step in assessing compliance.
Why heat resistance matters?
The heat resistance of non-metallic and insulating materials directly impacts the safety and durability of devices. A material’s ability to withstand high temperatures minimizes the risk of:
- Device failure.
- Structural damage.
- Fires caused by overheating.
Meeting the requirements of the PN-EN 60695-10-2 standard is not just a legal obligation but also a key factor in ensuring the longevity and reliability of products.
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The ball pressure test is one of the most important methods for assessing the heat resistance of materials used in electrical and electronic devices. This method evaluates whether a product meets rigorous safety standards, such as PN-EN 60695-10-2. Heat resistance in non-metallic and insulating materials is not only a formal requirement but also a guarantee of safety and durability.
Manufacturers aiming to ensure the highest quality and compliance of their products can benefit from the advanced testing methods available at RCC Laboratory. Our cutting-edge equipment and expertise enable precise execution of the ball pressure test in accordance with current standards.
For more information, visit: rcc.com.pl.
