1 Scope and object
This part of IEC 60947 applies to separable contacts used in the utilization area considered, such as switching
elements for control circuits.
This standard takes into consideration two typical rated voltage areas:
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a) above (and including) 10 V (typically 24 V) where contacts are used for switching
loads with possible electrical erosion, such as programmable controller inputs;
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b) below 10 V (typically 5 V) with negligible electrical erosion, such as electronic
circuits.
This standard does not apply to contacts used in:
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– functional safety area. In case of contacts used in functional safety area, Annex N
of IEC 60947‑5‑1:2016 applies;
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– very low energy area of measurement, for example, sensor or thermocouple systems.
The object of this standard is to propose a method of assessing the performances of
low energy contacts giving
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– useful definitions;
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– general principles of test methods which are to monitor and record the behaviour of
contacts at each operation;
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– functional bases for the definition of a general testing equipment;
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– preferred test values;
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– particular conditions for testing contacts intended for specific applications (such
as switching of PC inputs);
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– information to be given in the test report;
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– interpretation and presentation of the rest results.