Hammer tests (Test Eh) - enclosure impact resistance from 0.14 to 50 J; basis of the IK code.
The standard specifies three standardized and coordinated methods for testing a specimen’s ability to withstand impacts of specified severity: Test Eha – pendulum hammer, Test Ehb – spring hammer, Test Ehc – vertical (free-fall) hammer.
The impact-energy range is 0.14 J to 50 J, with impacts applied in specified directions. The method applies to electrotechnical products and is used to demonstrate mechanical resistance of enclosures and guards, including in safety assessment.
The test demonstrates that an enclosure or guard withstands an impact of specified energy without damage defined by the product specification (visual, dimensional and functional checks). The standard describes the apparatus and procedure; impact energy, number and locations of impacts and acceptance criteria are prescribed by the product standard or the IK classification according to IEC 62262. An “IEC 60068-2-75” entry without energy in joules or an IK code does not define product resistance.
The specimen is mounted normally on a rigid flat support or placed against such a support without gaps. The pendulum hammer (Eha) swings in a vertical plane around an axis 1000 mm above the measuring point and falls solely under gravity; a portable version is used for large or awkward specimens.
The spring hammer (Ehb) consists of a body with guide and trigger mechanism, striking element and release system with a release force up to 10 N. The vertical hammer (Ehc) falls freely from a specified height along a low-friction guide onto a horizontally positioned specimen.
Energy is selected from 0.14 – 0.2 – (0.3) – 0.35 – (0.4) – 0.5 – 0.7 – 1 – 2 – 5 – 10 – 20 – 50 J; values in parentheses remain as alternatives for backward compatibility. Unless otherwise specified, three impacts are applied at each location; the specification states whether the product operates during impact and whether its function is monitored.
After testing, visual, dimensional and functional inspections are performed.
Look for impact energy in joules or an IK code; the standard number alone only indicates the hammer method used. For an IK code, check that the manufacturer cites IEC 62262 (classification) and IEC 60068-2-75 (method) together and which hammer type was used - for IK07 and above, IEC 62262 provides for a vertical or pendulum hammer.
