BS EN 60947-5-4:2003+A1:2019 - Page 2

Low-voltage switchgear and controlgear. Control circuit devices and switching elements. Method of assessing the performance of low-energy contacts. Special tests | Status: Current

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:

1. 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;
2. b) below 10 V (typically 5 V) with negligible electrical erosion, such as electronic circuits.

This standard does not apply to contacts used in:

• – functional safety area. In case of contacts used in functional safety area, Annex N of IEC 60947‑5‑1:2016 applies;
• – 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

• – useful definitions;
• – general principles of test methods which are to monitor and record the behaviour of contacts at each operation;
• – functional bases for the definition of a general testing equipment;
• – preferred test values;
• – particular conditions for testing contacts intended for specific applications (such as switching of PC inputs);
• – information to be given in the test report;
• – interpretation and presentation of the rest results.