This part of 60947 specifies requirements for three-position enabling switches. These switches are used as components of enabling devices described in 10.9 of 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 9.2.6.3 of 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 60947-5-5).