Low-voltage switchgear and controlgear – Part 5-8: Control circuit devices and switching elements – Three-position enabling switches
|Publication Date:||1 October 2006|
|ICS Code (Low voltage switchgear and controlgear):||29.130.20|
This part of IEC 60947 specifies requirements for three-position enabling switches.
These switches are used as components of enabling devices described in 10.9 of IEC 60204-1 to provide signals that,
a) when activated, allow machine operation to be initiated by a separate start control, and
b) when de-activated,
i) initiate a stop function, and
ii) prevent initiation of machine operation.
NOTE 1 The enabling control function is described in 184.108.40.206 of IEC 60204-1.
NOTE 2 This standard does not deal with enabling devices.
This standard does not apply to:
− three-position enabling switches for non-electrical control circuits, for example hydraulic, pneumatic;
− enabling switches without three-position mechanism;
− emergency stop devices (see IEC 60947-5-5).