International Electrotechnical Commission

Low-voltage switchgear and controlgear – Part 5-9: Control circuit devices and switching elements – Flow rate switches - Edition 1.0
 N 60947-5-9

Annotation

Scope and object

This part of IEC 60947 applies to flow rate switches that sense the rate of flow of a gas, a liquid or a granular solid. These switches change their output state if a pre-set value for the speed of flow is exceeded.

These flow rate switches are self-contained, have semiconductor switching element(s) and are intended to be connected to circuits, the rated voltage of which does not exceed 250 V 50 Hz/60 Hz a.c. or 300 V d.c.

This standard does not specify the additional measures that are necessary for flow rate switches used in conjunction with explosive sensing materials and/or in an explosive location.

This standard is not intended to cover devices with analogue outputs.

The object of this standard is to state for flow rate switches:

– definitions;

– classifications;

– characteristics;

– product information;

– normal service, mounting and transport conditions;

– constructional and performance requirements;

– tests to verify rated characteristics.