What is an Electrical Insulation System?
The International Electrotechnical Commission [IEC] document 61857 offers the following definition:
- Electrical Insulation Systems [EIS] – An insulating structure containing one or more Electrical Insulating Materials [EIM] together with associated conducting parts employed in an electrotechnical device.
The important aspect of this definition is that an EIS evaluates a total of two or more materials [at least one EIM with at least one conductive part] in a single combined test object. The inclusion of materials into a single test object allows for the evaluation of interactions that may occur between the materials, which cannot be evaluated when the traditional EIM level of testing is conducted.
The type of interaction could be chemical related – as one material decomposes the “by-products” may cause other components to decompose more rapidly. There could be physical stress caused by different rates of thermal expansions and contractions. There could be problems related to adhesion. EIS testing is intended to help identify potential problems, which may lead to a constructive solution.
Another important benefit of EIS testing is that because each type of EIM has different criteria used to establish a thermal class rating, trying to select EIM can become confusing and may lead to problems. By placing EIM and conductive parts into a single combined test object, a more accurate evaluation of the system (group) of materials can be established.
It is also important to keep in mind that an EIS test will evaluate the thermal life of the electrical insulating portion of the system. An EIS test has no physical strength testing and no evaluation of the conductive parts. This is the reason the test results are identified as an Electrical Insulation System.
In summary, an EIS is a group of EIMs combined and evaluated as a collective set.
ELTEK Labs conducts more EIS testing than any other laboratory in the world
EIS testing is applicable to a wide range of applications and purposes. This test methodology can be beneficial to evaluate such needs as:
- A new EIS
- New processing or comparison of processing
- Reduction of thickness of insulation in an established EIS
- To compare alternate suppliers/vendors of similar materials used in manufacturing
Applications for areas such as:
- House-hold appliances
- Power tools
- Coils / solenoids
- Wind Turbine
Industries such as:
The test methods of the evaluation of Electrical Insulation Systems (EIS) are developed mainly by two organizations: IEEE and the IEC. The complete list of Standards for EIS testing at ELTEK Labs is available on our EIS Test List.
ELTEK Labs has over a hundred Thermal Aging ovens in three sizes with the capability for temperatures up to and including 350°C, four freezers for Cold Shock exposure at temperatures down to -40°C, and vibration tables for mechanical stress up to 10g.
High Voltage up to 150kVAC and Impulse testing up to 48kV can also be performed on motors, generators, coils, transformers, lab models, straight bars, or other configurations within the above limits of impulse stress and within limits of the size and configuration of the product. Please refer to the Impulse Test page to learn more about our Impulse Testing Capabilities.